Programmable Delay Detonator

PROGRAMMABLE ELECTRONIC DELAY DETONATOR.DOC

ABSTRACT


2

ABSTRACT

The detonator includes means for charging the capacitor from the supply in response

to occurrence of a first signal and for transferring stored electrical energy to the explosive

thereby to fire the explosive in response to occurrence of a second signal; and means for

storing an electrical representation of the firing delay time supplied from the firing

console, for responding to a first command from the firing console by transmitting the

firing delay time representation stored in the apparatus to the firing console, for supplying

the first signal in response to a second command from the firing console, and for

supplying the second signal as soon as a time interval, commencing on a third command

from the firing console, has elapsed, which time interval is substantially equal to the

firing delay time stored in the module.


3

LIST OF FIGURES


4

LIST OF FIGURES: - PAGE NO.

FIG.4.1.PLAIN DETONATOR 25

FIG.4.2.ELECTRIC DETONATOR 26

FIG.4.3.DELAY ELECTRIC DETONATOR 27

FIG.4.4.ELECTRONIC DETONATOR 28

FIG.4.5.FACTORY PROGRAMMED DETONATION SYSTEMS 29

FIG.4.6.FIELD PROGRAMMED DETONATION SYSTEM 30

FIG.5.1.TOWER OF VAL-FOURRÉ DISTRICT OF

MANTES-LA-JOLIE, FRANCE 34

FIG.5.2.CHUQUICAMATA MINE 34

FIG.5.3.BLAST AT PUNDI-E QUARRY, WEST BOKARO 35

FIG.7.1.BLOCK DIAGRAM OF TIME SETTER AND TIMER UNIT OF

DETONATOR 42

FIG.8.1.CIRCUIT DIAGRAM OF TIME SETTER UNIT 44

FIG.8.2.CIRCUIT DIAGRAM OF TIMER UNIT 46

FIG.9.1.FLOWCHART OF WORKING OF PROGRAMMABLE

ELECTRONIC DELAY DETONATOR 53

FIG.9.2.FLOWCHART FOR THE TIMER 54

FIG.9.3.FLOWCHART FOR SERIAL COMMUNICATION OF

TIME SETTER UNIT 55

FIG.9.4.FLOWCHART FOR SERIAL COMMUNICATION OF

TIMER UNIT 56

FIG.13.1.MULTIPLEXED DETONATOR SYSTEM 65


5

FIG.A.1. TIME SETTER UNIT 72

FIG.A.2. TIMER UNIT 73

FIG.B.1.PIN CONFIGURATION OF AT89C51RD2 74

FIG.B.2.44 KEYPAD 75

FIG.B.3.162 LCD DISPLAY 75

FIG.B.4.REGULATOR IC 7805 76

FIG.B.5.MAX 232 IC 76

FIG.B.6. PIN CONFIGURATION OF ATTINY 12 77


6

CHAPTER 1

INTRODUCTION


7

1. INTRODUCTION: -

The mining and explosives industry is rapidly adopting technology in all forms in

order to improve performance. One such technology that is being developed to improve

blasting efficiency and mining economics is the electronic detonator. Currently, there are

several types of electronics systems being tested and used in the industry, all of which

utilize some type of stored energy device to provide energy for their timing and firing

circuits. We will review the basic electronic detonator design concepts currently being

developed and used in the industry. If travel to almost any mine site today and you will

encounter the same type of technology that is changing the fundamental way other

industries will compete in the next millennium. It would be very common for the visitor

to encounter the latest forms of communication technology, computer systems, global

positioning systems (GPS), and laser measurement technologies, to name a few. Global

competition and increasing customer demands are forcing operators to seek out and adopt

these technologies in order for them to produce their product more economically and

more efficiently. The mine’s blasting operation is no exception. Today, many operators

employ the newest explosives, equipment, designs, and measurement tools in an effort to

ensure every pound of explosives is being utilized to its fullest potential.

One specific technology that has been under development for several years, by several

manufacturers, and is beginning to be tested and used increasingly in the industry is the

electronic detonator. Electronic detonators, of which there are several different types and

designs, all utilize stored electrical energy inside the detonator as a means of providing

the timing delay and initiation energy. All other detonator technologies, including shock

tube, electric or safety fuse initiated, utilize pyrotechnic energy as a means of delay and

initiation. Figure 1 shows the basic components and design of a typical shock tube

detonator, electric detonator and an electronic detonator.

Presently known delay detonators have a built-in chemical delay located between the

fuse head and primary charge. The length of delay is affected by the use of differing

chemical mixes and lengths of the delay unit. It is believed that existing delay detonators

are frequently inaccurate, their inaccuracy stemming from the chemical delay element,

especially in long series delay detonators. The inaccuracies are such that detonators in a

delay series can explode out of sequence. Also, known electric delay detonators have a


8

significant risk of accidental detonation by static electricity, stray currents, induction from

overhead power cables, and radio waves. Known delay detonators are believed to be less

than fully secure from use by unauthorized personnel.

Among the several objects of the project are to replace chemical delay by a compact

electronic package exhibiting substantially greater flexibility of operation for an electrical

delay detonator; to significantly increase delay detonator accuracy; to increase delay

detonator flexibility so that one integrated electronic unit is programmable for any delay

time; to increase delay detonator safety over presently available delay detonators; to

provide an electronic delay detonator capable of two-way communication with a

detonation controller in order to provide status information about the integrated

component within the blasting delay detonator unit; to provide an electronic blasting

delay detonator unit having a fail-safe mode of operation incorporated into the device to

prevent premature ignition of the detonator; to provide an electronic blasting delay

detonator unit which recognizes a unique detonation code to start its delay timer

sequence; to provide an electronic blasting delay detonator unit having a power storage

capability within the device to allow independent operation once the detonation code has

been recognized; to provide an electronic blasting delay detonator unit having power up

and power down modes of operation which are usable in the event it is necessary to abort

the firing of a detonator network; to provide a precision electronic blasting delay

detonator unit utilizing attached or self-contained integrating timing circuits which can be

controlled through a single pair of wires and so that two or more such detonator units are

connectable in a parallel wired electrical network; to provide an electronic blasting delay

detonator unit which is able to be charged or fired by electrical means; to provide an

electronic blasting delay detonator unit which is able to electronically respond to an

integrated initiation device immediately prior to blasting giving status, program delay

time, and designated number; to provide an electronic blasting delay detonator unit

having a factory programmed security code unique to the operator which excludes

unauthorized use; to provide an electronic blasting delay detonator unit which can be

rendered harmless by issuing an abort command from a firing console; to provide an

electronic blasting delay detonator unit having a security code which is unique to the user

and which can be kept secret with the manufacturer so that the user need not know the

code and fire control command which initiates timing circuits and subsequently

capacitive discharge and firing of the individual detonators; to provide an electronic


9

blasting console system compatible with the foregoing electronic blasting delay detonator

units having a fire control program requiring a single user security code for usage; to

provide an electronic blasting delay detonator unit having three leg wires, two long ones

for power and firing purposes and the third solely for factory programming which can be

clipped and sealed.


10

CHAPTER 2

ORGANIZATION PROFILE


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2. ORGANIZATION PROFILE: -

ARMAMENT AND RESEARCH DEVELOPMENT ESTABLISHMENT

Dr. Homi Bhabha road Pashan, Pune-411021

2.1. BACKGROUND

Established in 1958, Armament Research & Development Establishment is on the

threshold of the fifth decade of its existence, under defense research & development

organization.

The task of Armament R&D was entrusted to ARDE to achieve the cherished goal of

self-sufficiency in the vital field of Armaments. ARDE embarked on its mission in a

rudimentary facility within the campus of Ammunition Factory, Kirkee and personnel

were drawn from erstwhile Technical Development Establishment (Weapons) located in

Jabalpur and Technical Development Establishment (Ammunition) at Kirkee. In 1966,

ARDE moved to its presort location at Pashan on the out-skirts of pune City, where its

distinguished neighbor is the National Chemical Laboratory, a major CSIR Laboratory.

We are indeed fortunate to be located in a city with a very strong Science and Technology

culture and to have the resources of several sister R&D Labs/Establishments, Higher

Academic Institution, R&D Centers in the Non-Defense Sector, the industries in and

around the environs of Pune and Mumbai Metropolis.

The progress of ARDE over the past 40 years can be viewed as a journey from the

"know-what" and "know-how" phase to the "know-why" phase of armament design and

development. The capability of ARDE embraces the whole gamut of research,

development, prototyping, test and evaluation, and transfer of technology activities,

including limited scale pilot-plant production of crucial items in the complex, multi-

disciplinary field of conventional armament technology.


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2.2. ROLE

The Armament Research & Development is primarily concerned with research,

design & development in the field of conventional armaments for all the three Defense

Services. One of the largest R&D Establishments in the DRDO, it is the lead

Establishment in the conventional armament group of labs/establishments.

The Charter of Duties of ARDE as envisaged at its formation has undergone

considerable changes though the role per se remains more or less unaltered. The current

Charter of Duties broadly covers the following:

Design and development of indigenous armament stores to meet Services'

requirement & to establish their production.

Assistance in the technical evaluation and subsequent production of foreign stores.

AHSP (Authority Holding Sealed Particulars) Duties till Establishment of free-

flow production of newly developed stores.

Design and development of stores for other agencies (e.g. Home Ministry).

Basic/applied research.

Modelling and software for armaments.

It is seen that the Charter of Duties encompasses the entire gamut of activities which

goes by the generic name of R&D viz., research, design, development, testing, evaluation,

production, quality assurance and documentation.

The work at ARDE embraces a wide range of disciplines including applied

mechanical, electrical and aeronautical engineering, electronics, applied chemistry,

physics, mathematics and ballistics, operational research, metallurgy and material

sciences. The advice and assistance of higher academic institutions like ISRO, CMTI and

the industry in both Public and Private Sector, is actively and frequently enlisted for

completing the multifarious tasks related to the projects undertaken by ARDE.


13

CHAPTER 3

OBJECTIVE OF THE PROJECT


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4. OBJECTIVE: -

Detonators are very essential devices in many fields of application. They should be

very accurate in their functioning for reliable operation. For that the time delay generated

by the detonators should be very accurate. The programmed delay and the testing delay

should not vary much i.e. there should be very less error between the two.

The detonators, which have been invented till date, are having a fixed delay for their

operation and that to a very large delay ranging from 200ms to 10s. Hence, the attempt in

this project will be to reduce the delay and also to generate a variable delay for the

detonators as per the requirement of the situation.

The other various objectives of this project are: -

To provide greater flexibility of operation for an electronic delay detonator.

To significantly increase delay detonator accuracy.

To increase delay detonator flexibility so that one integrated electronic unit is

programmable for any delay time.

To increase delay detonator safety over presently available delay detonators.

To provide an electronic delay detonator capable of two-way communication with

a detonation controller in order to provide status information about the integrated

component within the blasting delay detonator unit.

To provide an electronic blasting delay detonator unit which recognizes a unique

detonation code to start its delay timer sequence (optional).

To provide a precision electronic blasting delay detonator unit utilizing attached

or self-contained integrating timing circuits which can be controlled through a

single pair of wires and so that two or more such detonator units are connectable

in a parallel wired electrical network

To provide an electronic blasting delay detonator unit which is able to be charged

or fired by electrical means.

To provide an electronic blasting delay detonator unit which can be rendered

harmless by issuing an abort command from a firing console.

To provide an electronic blasting delay detonator unit having a security code

which is unique to the user and which can be kept secret (optional).


15

UNIQUE FEATURES: -

In addition to highly accurate timing circuits, the micro-chip design described herein

incorporates:

1. Safety elements, including a unique fire control command which eliminates the

majority of types of accidental electrical initiation.

2. On-line programmability such that a single detonator may be programmed for any

delay period.

3. A factory programmed security code unique to the operator which will provide a high

degree of security and exclude unauthorized use.

An important concept to consider in the design of electronic detonator of the

project is that it need only have two wires and therefore arrays of such devices would be

designed simply to be wired together in parallel. In addition, a very large number of

different delays could be initiated using the present standard two blasting lead wire

system.

Read-only-memory (ROM) holds the firing console program and security code

information which is secret even from the normal authorized user. Random access

memory (RAM) holds information input from the keyboard and provides memory

locations for calculations and formation of communications


16

CHAPTER 4

LITERATURE SURVEY


17

4. LITERATURE SURVEY: -

4.1. TYPES OF EXPLOSIVES

In considering the use of high explosives, the first requirement is to use the most

effective explosive available for the situation. This will require the selection of a burster

with maximum effect and acceptable safety level. This will usually mean using the

smallest possible amount of suitable primary explosives. In practice, it is usually found

that maximum efficiency can often be achieved by using a very small primary charge to

explode a secondary charge which builds up the initiating shock to where full detonation

of the burster charge is obtained. Such an intermediate charge is known as a booster. The

combined system of the primary charge and booster charge form an explosive train,

which together with the main charge (bursting charge) form the explosive system of the

weapon.

Main classifications of explosives:-

By velocity

By sensitivity

By job function

By science

By chemistry

By velocity

-Low

e.g. black powder or gun powder

-Medium

e.g. Mercury Fulminate (VOD=4480 m/s)

-High

e.g. HMX (VOD=9110 m/s), also TNT, PETN


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By sensitivity

- Primary

A very sensitive explosive such as Mercury Fulminate or Lead Azide

Typically used as initiators in detonators

Sensitive to heat, shock, friction and static electricity

- Secondary

Typically high velocity shockwave propagators such as PETN or boosters

Insensitive to normal handling

- Tertiary

Typically blasting agents such as ANFO

Very insensitive and often require a booster for optimal energy release

By job function

- Initiator

Any devise that “starts” the explosive process

- Detonator


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Typically a blasting cap which contains an initiator (nickel wire attached to a

primary explosive) that is in turn attached to a high explosive shockwave

propagator

- Booster

Increases or boosts the energy and wave velocity through a column charge

Typically made 50/50 PETN/TNT

- Primer

A booster with a detonator in it

- Blasting Agent

A tertiary bulk explosive such as ANFO

.By science

- Mechanical

Can be due to chemical or non-redox reactions, therefore the reaction may or may

not be an oxidation/reduction reaction.

A boiler explosion is a mechanical explosions. In both cases, more gas is

produced than can be effectively vented in a closed container. However if the

reactants are unconfined than neither of these cases are explosive.

The firing of a gun can be considered a mechanical explosion as well.

- Nuclear

The reactions are on a subatomic level and energy transfer is the most efficient

known. The issues here deal with critical mass/density

12 kg of 235U has the approximate effect of 2000 tons of TNT

- Chemical

This course will deal primarily with chemical explosives.

These compounds typically pose little residual environmental challenges and are

almost always simple redox reactions, allowing us to exercise conventional

thermo-chemistry, dynamics, and physics.

By chemistry

- Inorganic


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Inorganic compounds are often composed of metal-salts.

Inorganic compounds are considered all compounds except hydro carbons, their

derivatives, and some compounds of carbon

- Organic

Organic compounds are primarily composed of carbon, hydrogen, nitrogen, and

oxygen (i.e. Hydrocarbons)

Organic compounds are considered to be all compounds of carbon, except for

some binary and tertiary compounds

The basic high explosive train consists of the detonator, booster, and bursting

charge. The high explosive charges are loaded into their containers by one of three

methods:

cast-loaded

pre-loaded

extrusion

4.1.1. Propellants

Propellants are classified as single-base, double-base, and composite. Single base

propellants include compositions that are principally gelatinized nitrocellulose and

contain no high-explosive ingredient such as nitroglycerin. Double-base propellants are

mainly compositions that are predominately nitrocellulose and nitroglycerin. Composite

propellants are compositions that contain mixtures of fuel and inorganic oxidants but do

not contain a significant amount of nitrocellulose or nitroglycerin.

There are many different types of propellants currently in use. Some of the more

frequently used types are black powder and smokeless powder.

4.1.2. Initiating Explosives

Under normal conditions, initiating explosives will not burn, but they will detonate if

ignited. Their strength and brisance are inferior, but they are sufficient to detonate high

explosives. Because of their sensitivity, they are used in munitions for initiating and

intensifying high-order explosions.


21

Mercury fulminate is white when pure but ordinarily, it has a faint brownish

yellow or gray tint. It is a heavy, practically non-hygroscopic, crystalline solid.

Lead azide is a crystalline, cream-colored compound which is practically

insoluble in water. When lead azide is stored in water, however, care must be

taken to assure that the water is free of bacteria-forming impurities which may

react with the dextrinated lead azide to form a gas.

Lead Styphnate has two forms: six-sided monohydrate crystals and small

rectangular crystals. Lead styphnate varies in color from yellow to brown. Lead

styphnate is particularly sensitive to fire and the discharge of static

electricity.

Tetracene is a colorless or pale yellow material. It is soluble in strong

hydrochloric acid but practically insoluble in alcohol, water, benzene, ether, and

carbon tetrachloride..

(DDNP) is a yellowish brown powder. It is soluble in acetic acid, acetone, strong

hydrochloric acid, and most of the solvents but is insoluble in water. A solution

of cold sodium hydroxide may be used to destroy it. DDNP may be desensitized

by immersing it in water, as it does not react in water at normal temperature.

4.1.3. Auxiliary Explosives

The explosives used as auxiliary explosives are less sensitive than the primary high

explosives that are employed in initiators, primers, and detonators. However, they are

generally more sensitive than those high explosives used as filler charges or bursting

explosives.


22

Tetrytol is a cast mixture of tetryl and TNT and is designed to obtain a tetryl

mixture that may be used in burster tubes for chemical bombs, in demolition

blocks, and in cast shaped charges.

PETN (Pentaerythritoltetranitrate) is one of the strongest known high explosives.

It is more sensitive to shock or friction than TNT or tetryl, and it is never used

alone as a booster. It is primarily used in booster and bursting charges of small

caliber ammunition.

Tetryl (Trinitrophenylmethylnitramine) can be initiated from flame, friction,

shock, or sparks; it burns readily and is quite likely to detonate if burned in large

quantities.

TNT (Trinitrotoluene) is a constituent of many explosives, such as amatol,

pentolite, tetrytol, torpex, tritonal, picratol, ednatol, and composition B. It has

been used under such names as Triton, Trotyl, Trilite, Trinol, and Tritolo. In a

refined form, TNT is one of the most stable of high explosives and can be stored

over long periods of time. It is relatively insensitive to blows or friction.

4.2. DEFLAGRATION VS. DETONATION

Deflagration is a process of subsonic combustion that usually propagates through

thermal conductivity (hot burning material heats the next layer of cold material and

ignites it).

Detonation is a process of supersonic combustion in which a shock wave is

propagated forward due to energy release in a reaction zone behind it. It is the more

powerful of the two general classes of combustion, the other one being deflagration. In a

detonation, the shock compresses the material thus increasing the temperature to the point


23

of ignition. The ignited material burns behind the shock and releases energy that supports

the shock propagation. This self-sustained detonation wave is different from a

deflagration that propagates at a subsonic speed (i.e., slower than the sound speed of the

explosive material itself), and without a shock or any significant pressure change.

Because detonations generate high pressures, they are usually much more destructive than

deflagrations.

Deflagrations are thermal processes that proceed radially outward in all directions

through the available fuel away from the ignition source. As the volume of the reaction

zone expands with every passing moment, the larger surface area contacts more fuel, like

the surface of an inflating balloon. The reaction starts small and gathers energy with time.

This process occurs at speeds depending largely on the chemistry of the fuel--from 1 to

10 meters per second in gasoline vapors mixed with air to hundreds of meters per second

in black powder or nitrocellulose propellants. These speeds are less than the speed of

sound in the fuel (The speed of sound through a material is not constant, but dependent on

the density of the material; the higher its density, the higher the speed of sound will be

through it). Deflagrations, then, are thermally initiated reactions propagating at subsonic

speeds through materials like: mixtures of natural gas and air, LP gases and air, or

gasoline vapors and air; black powder or nitrocellulose (single-base) propellants or rocket

fuels. The pressures developed by deflagrating explosions are dependent on the fuels

involved, their geometry, and the strength (failure pressure) of a confining vessel or

structure (if any). Pressures can range from 0.1psi to approximately 100psi for gasoline:

air mixtures to several thousand psi for propellants. Times of development are on the

order of thousandths of a second to a half-second or more. Maximum temperatures are on

the order of 1000-2000 degrees Celsius (2000-4000 degrees Fahrenheit).

Detonations are very different. While a detonation is still chemically an oxidation

reaction, it does not involve a combination with oxygen. It involves only special

chemically unstable molecules that, when energized, instantaneously splits into many

small pieces that then recombine into different chemical products releasing very large

amounts of heat as they do so. High explosives are defined as materials intended to

function by detonation, such as TNT, nitroglycerine, C4, picric acid, and dynamite. The

reaction speeds are higher than the speed of sound in the material (i.e., supersonic). Since


24

most explosives are roughly the same density, a reaction speed of 1000 m/s (3100 feet per

second) is set as the minimum speed that distinguishes detonations from deflagrations.

Due to the supersonic reaction speed, a shock wave develops in the explosive (like the

sonic boom from supersonic aircraft) that triggers the propagating reaction. Detonation

speeds are on the order of 1000-10000 m/s so times of development are on the order of

millionths of a second. Temperatures produced can be 3000-5000 degrees Celsius and

pressures can be from 10000 psi to 100000 psi. It should be noted that a few materials can

transition from deflagration to detonation depending on their geometry (long, straight

galleries or pipes), starting temperature, and manner of initiation. Double-base smokeless

powders (containing nitroglycerine), perchlorate-based flashpowders, hydrogen/air

mixtures and acetylene (pure or with air) can detonate under some conditions.

The effects of detonations are very different from those of deflagrations.

Deflagrations tend to push, shove, and heave, often with very limited shattering and little

production of secondary missiles (fragmentation). Building components may have time to

move in response to the pressure as it builds up and vent it. The maximum pressures

developed by deflagrations are often limited by the failure pressure of the surrounding

structure. Detonations, on the other hand, tend to shatter, pulverize and splinter nearby

materials with fragments propelled away at a very high speed. There is no time to move

and relieve pressure so damage tends to be much more localized (seated) in the vicinity of

the explosive charge (and its initiator) than a deflagration whose damage is more

generalized. Damage from a deflagration tends to be more severe away from the ignition

point, as the reaction energy grows with the expanding reaction (flame) front.

4.3. TYPES OF DETONATOR

The various detonators that have been developed till date are described as follows:

4.3.1. Chemical (plain) detonator

- Have a primary (initiating) charge and a base charge of high explosive

- Primary charge of ASA

- Base charge of PETN or RDX


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Fig.4.1. Plain detonator

Chemical detonators are thin metal or paper cylindrical shells, open on one end for the

insertion of safety fuse, which contain various types of primary and secondary explosives.

They are sensitive to heat, shock and crushing and are designed to be initiated with safety

fuse or detonating cord. All detonators of this type are instantaneous and therefore, do not

have a delay element.

4.3.2. Instantaneous Electric Detonator

- First prototype emerged in late 1880s

- It is a replacement of safety fuse with electric wires connected to a fusehead

- Initiation is done by electric current passed through leg wires

4.3.3. Electric Detonator

- It has two cotton insulated leg wires, ignition mixture of mercury fulminate, high-

resistance platinum bridge wire and a sulfur plug

- Its design has changed slightly over the years

Electrical detonators are similar to non-electrical detonators except they are initiated

by the application of electrical current through electrical wires. The current causes a

bridge wire or match elements to heat/function thereby, causing the ignition charge to

explode which in turn, causes a chain reaction to cause the base charge to be initiated.

The wires are secured into the detonator by a closure plug, crimped into the shell, which


26

seals the explosive from moisture. In addition to sensitivity from heat, shock and

crushing, these products are subject to extraneous electricity due to the presence of

electrical wire.

Fig.4.2. Electric Detonator

4.3.4. Delay Electric Detonator

- It is same as instantaneous electric detonator, except for inclusion of delay powder train

- Delay time based on length and composition of delay powder

- Half-second delay during early 1900s; millisecond delay during 1943


27

Fig.4.3. Delay electric detonator

4.3.5. Electronic detonator

- Idea of electronic detonator was first discussed in the beginning of 1990s

- Recognized potential to increase detonator accuracy and improve customer results

- Costly technology has been used in this case

- Minesite drive to increase accuracy resulted in various manufacturers beginning to

develop and market versions of electronic detonator

- Several different designs have been developed under this although fundamental

structure is basically the same

- Computer chip is used to control the delay timing which uses electrical energy stored in

one or more capacitors to provide power for timing clock and initiation energy

- Therefore delay is achieved electronically not pyrotechnically (powder)

Fig.4.4. Electronic Detonator


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4.4. TYPES OF DETONATION SYSTEMS

There are probably a dozen different electronic detonator systems either in

development, or being utilized, in the world today. Their differences include detonator

construction, timing precision, communication protocol, blasting machines, tie-in,

connectors, etc. Although they are each uniquely different from one another, there are a

few basic design features that are common. A brief overview of the generic system

architectures found in the industry today is provided herein.

Electronic detonator systems can first be grouped into two basic categories:

Factory Programmed Systems

Field Programmed Systems.

Factory Programmed Systems, in most cases, have a fairly close resemblance to the

conventional hardware and components found with standard electric detonators. In some

cases, the user may even have a difficult time differentiating a wired electronic detonator

from a wired electric detonator. Even though these units may not appear to be different,

electronic detonators generally cannot be fired or shot using conventional blasting

machines or firing devices. Each system will have a unique firing code or communication

protocol, used to fire the detonators in the blast.

Factory Programmed Systems can be further grouped into specific types or styles.

There are Electrically Wired Systems, where each manufacturer has a specific wiring

style or methodology, and a Factory Programmed System that utilizes shock tube

technology to energize an electronic timing circuit within the detonator. Figures 4.5.

shows the basic configuration of these systems.


29

Fig.4.5. Factory Programmed detonation Systems

Field Programmed Systems utilize electronic technology to program delay times "on

the bench". Each system is manufactured for, or with, unique system architectures, styles,

hardware and communication protocol. There are no fixed delay times associated with

these detonators. These systems rely on direct communication with the detonator (either

prior to loading, after loading, or just prior to firing) for the proper delay time and

subsequent blast design. In general, these systems will utilize some type of electronic

memory, which allows them to be reprogrammed at any time up until the fire command is

given.

Designs, as well as amount and type of additional equipment necessary for use, vary

considerably in Field Programmable Systems. Example of system concept in use today is

shown in Figure 4.6. Figure 4.6. depicts a system concept that would utilize computer

technology to program detonators either directly from the blast machine or via blast

design software. Programming may also be done in some cases with handheld

test/programmers prior to final connection of the blast. Other system concepts may utilize

a handheld test and programming unit to check the detonator’s circuitry prior to final

connection to the blast machine. Following connection, the entire circuit can be checked

via the blasting machine for system level continuity.


30

Fig.4.6. Field programmed detonation system


31

CHAPTER 5

REAL TIME APPLICATIONS


32

5. REAL TIME APPLICATIONS: -

5.1. CASE 1: - Towers of the Val-Fourré district of Mantes-la-Jolie, France

Three apartment towers in the Val-Fourré district of Mantes-la-Jolie, France were demolished

with the help of Orica’s electronic detonator System on Sunday July 2, 2006. The demolitions

were part of a ten-year-old Urban Renewal Program that is being undertaken by the city located

30 miles (50 kms) northwest of Paris, and involves remaking what was once one of the least

attractive suburbs in France.

Built in the 1960’s-70’s, the three towers on Edgar Degas Street were called K1, K2 and K3

and stood 160 feet tall, but took less than 10 seconds to fall. The blast took three months to plan

and used 580 kgs of explosives and 3138 electronic detonators. This historic blast was also the

largest electronic demolition blast ever undertaken in Europe and was very close to being the

largest electronic blast of any kind ever fired in the world.

Several of France’s most experienced demolition companies were involved in this complex

project. Site management was handled by CEBTP and a different company was assigned to each

building. Melchiorre was responsible for K1, SMD for K2 and Cardem for K3. As well, local

company ATD supplied 3300 feet (1000 m) of water hose for dust suppression.

NEF Paris was responsible for the overall blast design with support from Orica Germany

personnel: Dirk Grothe, Jan Lindenau and Peter Reinders who provided valuable

recommendations and tips. The blast itself was fired by Guy Thomasson and Jean-Louis

Schreiber of NEF Paris, using 2 i-kon™ Blaster 2400S units in synchro mode.

The blast went off perfectly as planned and none of the surrounding buildings, some as close

as 120 feet, sustained any damage. As soon as the site is cleaned up, construction will begin on a

huge aquatic theme park.


33

5.2. CASE 2: - Chuquicamata mine

Chuquicamata mine is the largest and deepest open pit copper mine in the world. It is owned

and operated by state-owned codelco mining, Chile. It is located in Chile’s second region,

1600kms north of Santiago. The production is approximately 600000 tonnes/yr of fine copper.

The requirement was of very specific fragmentation size to maximize the output. Great depth

of mine means steeper slopes, which affect haul truck efficiency. A key geological challenge was

the lack of stability in the west wall, which is next to a fault line that runs through the pit.

Avoidance of wall collapses was critical. Location of mine required the equipment to be

subjected to extreme aridity, severe temperatures, high solar radiation levels and frequent strong

static electricity.

The mine consists of 7 different geological sectors and blast plans must be customized to each

unique area. Typical blast was 100 holes x 12 1/2” diameter on a 7m x 9m pattern, producing

about 250,000 tonnes of rock per shot, using a powder factor of 0.33 kgs per tonne. To increase

the safety and maintain highwall stability, blast size was restricted and bench height was reduced

from 26m to 18m. The electronic detonators were used to for this operation. The mine was

carefully explored with pattern expansion, increased blast size and potentially, steeper walls.

The blast resulted in Consistent fragmentation size with i-kon™ detonator, significantly

improved crusher and SAG mill efficiency, and reduced wear and tear on loaders and haul

trucks. Smaller rock size has reduced the amount and cost of mechanical and electrical energy

required in downstream copper extraction processes. Increased vibration control has reduced

blast impact on pit walls and contributed to overall pit stability. Reduced powder factor saves on

overall explosives consumption.


34

Fig.5.1. Tower of Val-Fourré district of Mantes-la-Jolie, France (courtesy: www.i-

konsystem.com)

Fig.5.2. Chuquicamata mine (courtesy: www.i-konsystem.com)

http://www.i-konsystem.com/


35

5.3. CASE 3: - Trial blast at Pundi-E Quarry of TISCO, West Bokaro

A trial blast was conducted at the sixth OB bench of Pundi East Quarry on 21st July 2004. The

strata consisted of medium-grained sandstone, massive nature. Bench height was 14m. The

diameter of the hole depth varied from 13 to 14m. Total number of holes was 33, distributed in

three rows. Burden from the free face to the first row was 2.5m. Burden between the first and

second row was 4m. Spacing between holes was 4.5m for all three rows. Top stemming was

3.5m for all the holes. Casting of the muck was required up to 40-45m in the de-coaled area.

Holes were charged with 225.40kg of Site-Mixed Emulsion (SME) from orica. The electronic

detonator with a 15m harness wire length was used for each hole. Initiation point of the hole was

maintained at 1.0m above the bottom of the hole. The total amount of explosive fired was

7438.20kg.

The trial blast resulted in a very good fragmentation. The muck was thrown to 45m to the de-

coaled area. The height of the muck profile was less than 4m. Flyrock was completely controlled.

The blasting bench was very clean after the blast. No overbreak resulted and the cut was

absolutely neat.

Fig.5.3. Blast at Pundi-E Quarry, West Bokaro (courtesy: Journal of Explosive Engineering)


36

CHAPTER 6

SIGNIFICANCE OF DELAY


37

6. SIGNIFICANCE OF DELAY: -

A delay is a device that causes time to pass from when a device is set up to the time that it

explodes.

6.1. TYPES OF DELAY: -

There are many types of delay. They are discussed as follows: -

6.1.1. Fuse delay

It is extremely simple to delay explosive devices that employ fuses for ignition. Perhaps the

simplest way to do so is with a cigarette. An average cigarette burns for between 8-11 minutes.

The higher the "tar" and nicotine rating, the slower the cigarette burns. Low "tar" and nicotine

cigarettes burn quicker than the higher "tar" and nicotine cigarettes, but they are also less likely

to go out if left unattended, i.e. not smoked. Depending on the wind or draft in a given place, a

high "tar" cigarette is better for delaying the ignition of a fuse, but there must be enough wind or

draft to give the cigarette enough oxygen to burn. People who use cigarettes for the purpose of

delaying fuses will often test the cigarettes that they plan to use in advance to make sure they

stay lit and to see how long it will burn. Once a cigarettes burn rate is determined, it is a simple

matter of carefully putting a hole all the way through a cigarette with a toothpick at the point

desired, and pushing the fuse for a device in the hole formed.

6.1.2. Chemical delay

Chemical delays are uncommon, but they can be extremely effective in some cases. The delay

would ensure that a bomb would detonate hours or even days after the initial bombing raid. If a

glass container is filled with concentrated sulfuric acid, and capped with several thicknesses of

aluminum foil, or a cap that it will eat through, then it can be used as a delay. Sulfuric acid will

react with aluminum foil to produce aluminum sulfate and hydrogen gas, and so the container

must be open to the air on one end so that the pressure of the hydrogen gas that is forming does

not break the container.

6.1.3. Timer delay

There are several ways to build a timer delay. By simply using a screw as one contact at the

time that detonation is desired, and using the hour hand of a clock as the other contact, a simple

timer can be made. The main advantage with this type of timer is that it can be set for a


38

minimum time of ms. By attaching the wires of a squib or igniter to a the supply, a timer with a

delay of up to 25ms can be made. Such a timer could be extremely small.

6.2. NEED OF APPLYING DELAY

For proper fragmentation

To reduce ground vibration and air blast

To minimize the destruction and increase the output

To enable sequential blasting

6.2.1. Ground Vibration

When an explosive detonates within a borehole it causes the rock in the immediate vicinity to

crack or distort. Outside this immediate vicinity of the blast site permanent deformation does not

occur, instead the rapidly decaying stress waves from the explosion cause the ground to exhibit

elastic properties whereby the rock particles are returned to their original position as the stress

waves pass. This causes ground vibration to radiate away from the blast site, the effect reducing

as distance increases.

It is always in the operator's interest to reduce both ground and airborne vibration from blast

events to the minimum possible for any specific blast design because it is this that substantially

increases the efficiency, and therefore, economy of blasting operations.

6.2.2. Air-Blast

All of the energy liberated by the explosive is initially in the form of a highly compressed gas.

Some of that gas escapes to the surface and travels through the air as airblast. The largest part of

the compressed gas energy goes into breaking and moving rock. The sudden movement of the

rock at its face or at the ground surface also causes a disturbance, which propagates through the

air. Parts of these disturbances are in the audible range of frequencies (>20 Hz) and are

collectively called noise. Some of these disturbances are in the sub-audible range. Both parts

together are called airblast. If sufficiently intense, they can cause buildings to vibrate and crack

windows to vibrate or break and discomfort or pain to individuals.


39

Air blast is usually caused by one of three mechanisms. The first cause is energy released

from unconfined explosives such as uncovered detonating cord trunklines or mudcapping used in

secondary blasting. The second cause is the release of explosive energy from inadequately

confined borehole charges resulting from inadequate stemming, inadequate burden or mud

seams. The third cause is movement of the burden and the ground surface. Blasts are designed

to displace the burden.


40

CHAPTER 7

WORKING PRINCIPLE AND

MODEL CONCEPT


41

7.1. WORKING PRINCIPLE: -

The detonator unit works on the principle that whenever the counting in the counter is

completed, a port pin goes high. This high pin is used for further processing.

The user feeds the desired delay in ms within the range from the keyboard, which is converted

into equivalent count value required to give the delay by the program.

The formula for generating the desired count value for a particular delay time is as follows: -

N= (Time delay Crystal frequency) / 12

Count value = 65536 - n

The counter will start working only after entering the correct password. In case of wrong

password the system will not work.


42

7.2. BLOCK DIAGRAM: -

Fig.7.1. Block diagram of time setter and timer unit of detonator

The control unit block diagram basically consists of a keypad, a LCD display, a power supply

unit viz. battery and a microcontroller unit. All the inputs are entered through the keypad. The

inputs entered are directly displayed on the LCD screen. The microcontroller unit performs the

necessary calculation and interfacing operations so that the control unit and the timer unit

communicate with each other. The output driver section is the interface between the control and

timer unit.

The timer block diagram basically consists of a d.c. power supply which a 5-10V battery, a

regulator, an oscillator, a counter, a power-on-reset ckt. and an igniter device viz. squib. The

squib is basically a SCR. To the gate of the SCR the output of the counter circuit is given; to the

anode of the squib the stored energy of the capacitor is given. The output from this squib will

then ignite the explosive.

In the actual implementation the assembly of power-on-reset, oscillator and counter is

replaced by a microcontroller. The regulator will provide a constant voltage of 5V to the

microcontroller (POR, oscillator, counter).


43

CHAPTER 8

HARDWARE DESIGN


44

8. HARDWARE DESIGN: -

8.1. TIME SETTER UNIT: -

Fig.8.1. Circuit diagram for time setter unit


45

Time setter description:-

The time setter unit contains a power supply unit, a LCD display unit, a keypad matrix and a

communication section.

The power supply unit is a constant 5V supply. It consists of a regulator IC which can take a

maximum of 20V input voltage and in turn produces a 5V constant output voltage.

The keypad is used to enter the inputs into the system. The various inputs for the system are

detonator ID, delay time and password (optional). The keypad is connected to the port 2 pins of

the AT89C51RD2 microcontroller. Any key pressed will be sensed by the port 2 pins and the

corresponding key pressed will be displayed on the LCD display.

The LCD display connected to the port 0 of the microcontroller is a 16×2 display. It will

display the detonator ID, delay time entered by the user.

A MAX 232 IC is also connected to the TXD, RXD pins of the controller to facilitate the

serial communication between the time setter and the timer unit by converting the TTL standard

into the RS232 standards.

Whenever the user enters a particular detonator ID through the keypad, the value will get

displayed on the LCD screen. This ID will then be sent to the timer unit via serial

communication and then will get store into the EEPROM memory of the timer microcontroller.

Similarly the entered delay time will also get serially transferred to the timer part after

calculating the necessary count value for that particular delay time.

The crystal connected to the microcontroller provides the necessary frequency for the

operation of the microcontroller.


46

8.2. TIMER UNIT: -

Fig.8.2. Circuit diagram for timer unit


47

Timer description:-

The timer unit basically consists of an 8-pin microcontroller, a charging-discharging section

and ignitor section.

The purpose of using the 8-pin microcontroller is to achieve a detonator which is small in

size. The microcontroller used here is an AVR microcontroller. The timer microcontroller is used

to store the delay subroutine to generate the desired delay entered by the user.

The charging-discharging section consists of an NPN transistor which is used as a switch for

charging and discharging the storage capacitor. Two zener diodes have been employed in order

to provide the necessary voltages to the microcontroller and the charging capacitor for their

operation. The switching of the transistor is controlled from the time setter side. The base of the

transistor is connected to a port pin of the setter side microcontroller. At first the transistor is

kept ON so that the storage capacitor gets charged to the desired value. Then the transistor is

switched OFF so that the stored energy is discharged to the anode terminal of a SCR. Now when

the delay subroutine is called then the timer microcontroller will execute that routine and will

output a delay pulse which will act as gate pulse for the SCR and hence the SCR will get ON and

in turn will glow the LED. The SCR and the LED constitutes the ignitor section for the timer.

In the actual scenario this LED will get replaced by some explosives train in order to carry out

the blasting operation. All the data from the time setter side is received via the MAX 232 IC.


48

8.3. WORKING: -

First, d.c. current from battery is supplied to the electronic detonator in order to activate their

microcircuitry in the integrated delay circuit. Once this is performed, a command may be given

to power up their capacitive storage devices such as capacitor. When power storage is complete,

the electronic timing delays within each electronic detonator will be initiated at precisely the

same time by a complex firing code issued by the firing console after a firing button is depressed

by the operator. If, however, something is shown to be wrong by the firing console, the operator

may power down the detonator power storage units such as capacitor by issuing an abort

command, thus rendering the detonator harmless before disconnecting the firing console from

the firing circuit.

For safety, the detonator is made such that direct current passing through the circuit does not

initiate the device, initiation only being possible by the use of the correct signal. This eliminates

accidental initiation caused by stray currents, electromagnetic fields, radio waves, static

electricity, etc. However, in order to protect the microchip from accidental burn-out due to

current or voltage overloading in such a situation, a voltage regulating device and an associated

transient suppressor such as a varistor is provided.

8.4. SECURITY: -

For the purpose of security, a binary security code is used in the preferred embodiment of the

invention. The code is unique to the user or manufacturer. To eliminate unauthorized use this

code is kept secret with only the manufacturer knowing the combination. The user need not

know this code as it is integrated in the software control program supplied by the manufacturer

with the firing console. The security code controls the powering-up of the appropriate discharge

circuits until this command has been given, the detonator cannot be energized and fired. Thus the

blasting cap will not fire when linked up to any d.c. or a.c. power source. To fire the detonator or

a series of these detonators, one would therefore have to have in their possession not only a firing

console made or marketed by the manufacturer of the detonator, but one that is compatible with

the detonators one is going to use.

The construction includes three leg wires, two long ones for power and firing purposes, and

the third solely for factory programming which is clipped and sealed after this process. If,


49

however, programming in the field is required, the third wire may be left intact for later

programming.

Software is provided in the form of ROM packs (Read Only Memory-microchips) for

updating ease. Such software training packages can eliminate the need for blasting personnel

being sent to retraining courses, eliminating extra cost and lost man-time. Such programs can

even test the personnel as well as teach them and thus finally pass them out and permit them to

use the firing console in the true firing mode after several successful simulations.


50

CHAPTER 9

SOFTWARE DESIGN


51

9. SOFTWARE DESIGN: -

9.1. ALGORITHM

The basic algorithm for the working of the electronic delay detonator is shown in the attached

figure.

The software should work in the following manner: -

Initially both the microcontrollers of time setter unit and the timer module will be in the

reset condition.

Once the battery supply in switched ON, it will wake up both the microcontrollers.

Then one MENU screen should appear in the LCD display as,

1. Enter detonator ID 2.Enter delay 3. Fire

1. Enter detonator ID

When the user enters ‘1’ through the keyboard, then the LCD should display “enter the

detonator ID”.

Then the user will type the detonator ID as some 2-digit decimal number.

Then this ID value will be sent to the timer module via serial communication.

There it will be stored in the EEPROM memory of the timer microcontroller.

Then the control will return to the MENU screen.

2. Enter delay

When the user enters ‘2’ through the keyboard then the LCD should display “enter the

delay”.

Then the user will enter the delay value say ‘25’ (for 25ms delay) through keyboard.

Then the microcontroller of the time setter unit will calculate the necessary count value

for the entered delay value.

This calculated count value will then be sent to the timer module via serial

communication.

There it will get stored in the EEPROM memory of the timer microcontroller.

Then the control will return to the MENU screen.


52

3. Fire

When the user enters ‘3’ through the keyboard, then the LCD should display “charge the

capacitor”.

Then the user will enter ‘C’ through keyboard which will generate a high pulse at pin

P2.4 (pin no.25). This will short the transistor at the timer side and the storage capacitor

will get charged.

Now the LCD should display “abort or proceed”.

If the user enters ‘X’ then the control should return to the MENU.

If the user enters ‘A’ then setter microcontroller should generate a low pulse at pin P2.4

(pin no.25). This will switch OFF the transistor and hence the storage capacitor voltage

will get applied to the anode of the SCR in timer side.

When the user enters ‘F’, then the timer microcontroller must fetch (read) the stored

count value from the EEPROM memory and should execute the timing subroutine and

generate a pulse at pin PB2 (pin no. 7) for the gate of the SCR.

Apart from the above mentioned points, we can also keep the provision for the password

for nullifying the unauthorized access of the setter unit (this is optional). In this, setter will

have a unique security code. Only after entering that particular code, the setter will operate

otherwise not.

The software part also contains the LCD and keyboard interfacing programming.


53

9.2. FLOWCHARTS: -

S/W ON

power supply

MENU

2.Enter delay

Enter the delay to be

reqd.through keypad

Calculate the necessary

count value for the delay

Send this count value to the

timer through serial comm.

Store the count value in the

EEPROM of timer

microcontroller

Back to MENU

1.Enter det. ID

Type an ID code for

the det.

Send the code to the timer

through serial comm.

Store the code in the

EEPROM of timer

microcontroller

Back to MENU

3.Fire

S/W ON the

transistor

Proceed

or

Abort?

Switch OFF

transistor

Fetch the delay count

from EEPROM of

timer

Execute the delay

subroutine

Blast

Abort

Proceed

Fig.9.1. Flowchart of working of

programmable electronic delay detonator


54

9.2.1. Delay subroutine flowchart: -

Stop the timer

Fig.9.2. Flowchart for the timer

NO

YES

Start

Select one of

the timers

Select the

timer mode

Calculate/fetch

the count value

Enter count value in

timer register

Start the timer

Monitor the

timer flag

Is timer

flag bit

set?


55

9.2.2. Serial communication subroutine for time setter unit: -

Start

Set the timer mode

for communication

Set the baud rate

Set the serial mode

for communication

Start the timer

Set the timer in

transmitting mode

Load the SBUF

register with the data

to be sent

Monitor the transmit

interrupt flag

Is the data

sent?

Transmit next data

NO

YES

Fig.9.3.Flowchart for serial communication of time setter unit


56

9.2.3. Serial communication subroutine for timer unit: -

Start

Set the timer mode

for communication

Set the baud rate

Set the serial mode

for communication

Start the timer

Set the timer in

receiving mode

Is the data

received?

Monitor the receive

interrupt flag

Save the received data

in SBUF register

Receive next data

NO

YES

Fig.9.4. Flowchart for serial communication of timer unit


57

CHAPTER 10

ADVANTAGES OF THE PRESENT STATE OF ART


58

10. ADVANTAGES OF THE PRESENT STATE OF ART

The delay detonator of the project is a microcontroller based detonator model. So far the

various detonators that are developed till date have been employing different methods of delay

generation.

At first the chemical detonator came into the picture which employed a train of chemicals

for generating the delay before blasting. But the delay generated by chemicals (pyrotechnically)

is very unreliable, as they can never provide an accurate delay and hence causes uncontrolled

blasting and more destruction.

After that the next state of art that can into existent is the shock tube delay detonator. In this

model the delay is generated using a piezoceramic assembly which is used to convert the

mechanical vibration into electrical signal which is further used for the delay generation. But this

assembly is very complex in itself and very costly too. Hence this model is not used frequently.

The next type of delay detonator is the electrical detonator. In this case the delay is

generated using electric signal. The current causes a bridge wire or match elements to

heat/function thereby, causing the ignition charge to explode which in turn, causes a chain

reaction to cause the base charge to be initiated. This system is highly susceptible to extraneous

electricity, AC/DC voltages, stray currents, electrostatic discharge etc. and hence is not highly

reliable.

Now a days the electronic detonators are being employed which eliminates almost every

drawback of the earlier inventions. Under the electronic detonator, various concepts have been

employed for better performance. This includes counter based delay generation, timer chip based

delay generation.

The counter based delay detonator consists on separate oscillator section, counter section and

reset circuitary. All these separate sections used to increase the size of the detonator unit. Hence

the detonators formed are considerably bigger in size.

The delays generated by timer chip based detonator are of limited range. For example in case

of the timer IC 555 the delay time depends on the resistor and capacitor used which are not


59

reliable. Hence the requirement is for one such model which can eliminate all the above

drawbacks.

For this a microcontroller based detonator model is highly efficient. In this project a

microcontroller based delay detonator has been designed which can provide the following

enhanced features: -

1. The microcontroller includes the oscillator, counter and reset circuit within itself hence the

size of the timer unit reduces considerably.

2. The microcontroller can generate large range of delay time based on the crystal frequency.

3. The microcontroller provides an electronic delay detonator capable of two-way

communication.

4. On-line programmability such that a single detonator may be programmed for any delay

period.

5. The detonator is blasted by specific blasting machine (setter). Hence outside access is

prohibited.


60

CHAPTER 11

SPECIFICATIONS


61

11. SPECIFICATIONS: -

Physical size of PCB : 40mm by 60mm

Delay timing : Settable at factory

Multiples of 25ms or 500ms

Accuracy of 1ms(if possible 100µs)

Over/under voltage : no operation

Reliability : 100%

Charging voltage : approx. 25V

Testing voltage : 5V d.c. ; 3-5mA

Firing current : 1A for 4ms

Polarity : f ree

Connection : 2 wire system for charging & firing in parallel or

bus system.

Blasting machine : The detonator should fire with our blasting

machine only.

Password for unauthorized operation control.

Sympathetic detonation : 1. When one detonator fires at 50m in water

then no other detonator should fire at that

time.

2. Delay timings should not be affected by

shock.

Construction : 1. It should have 2 pins at one end for

crimping/soldering.

2. It should have 2 cups on the other end for

connection to the lead wire.

3. It should be potted with suitable potting

material so as to meet environmental

conditions as per miligrade std.331B.

Environmental conditions : 1. It should be designed to work in all environ-

mental conditions (snow, desert, sea).

2. It should be properly packed to survive shock,

vibration, acceleration/deaccelaration during

handling, transportation & storage.

3. The electronic timer & time setter should be

subjected to qualification tests as per

miligrade std.331B.

Shelf life : 10 years.


62

CHAPTER 12

EXPERIMENTATION AND TESTING


63

12. EXPERIMENTATION AND TESTING: -

S.NO. DELAY ENTERED

(in ms) DELAY

OBTAINED (in ms) ACCURACY

1

2

3

4

5

6

7

8

9

10


64

CHAPTER 14

RESULT AND CONCLUSION


65

14. RESULT AND CONCLUSION: -


66

CHAPTER 13

FUTURE PROSPECTS


67

13. FUTURE PROSPECTS: -

Technologies are being updated every minute. Today is the age of miniaturization and

simplicity. A more compact and reliable material will find its way up in the new-age markets.

This project basically works on this main aim. The programmable electronic delay detonator

of this project uses an efficient 8051 microcontroller. Hence it fulfills the requirement of

compactness, reliability and speed.

However the timer circuit designed is required to be of very small size. Hence using the SMD

components and using 2-layer or 4-layer PCBs, which will reduce the size of the circuit

considerably, can do the further improvement.

Another further scope of this project may be to multiplex the system i.e. to connect a number

of detonator units to one common bus system. This will help in operating a large number of

detonator units at a same time that to using a single bus system. The multiplexed system will

look like as shown in the following figure.

Fig.13.1. Multiplexed detonator system


68

REFERENCES


69

15. REFERENCES: -

1. Ochi; Koji (Iwamizawa, JP), Harada; Masahide (Sapporo, JP), Kobayashi; Kunio

(Takasaki, JP) ; US Patent no. 4,984,519; “Delay circuit for use in electric blasting system” ;

January 15,1991.

2. Pallanck; Robert G. (Windsor, CT), Rode; Kenneth A. (Collinsville, CT); US Patent no.

5,173,569; “Digital delay detonator” ; December 22,1992.

3. Prinz; Francois (San Jose, CA), Steeves; Kent (Newark, DE), Atkeson; Peter L. C.

(Newark, DE), Walsh; Brendan (Elkton, MD), Wilson; J. Michael (Gilroy, CA); US Patent

no. 5,460,093; “programmable electronic time delay initiator”; October 24,1995.

4. Gwynn,III,James C.(Litiz,PA); US Patent no. 5,621,184; “programmable

electronic timer circuit” ; April 15,1997.

5. Eddy, Christopher L.; (McCandless, PA) ; Singhal, Rajeev N.; (Pittsburgh,

PA); US Patent no. 20030029344; “System for the initiation of rounds of individually delayed

detonators”; February 13, 2003.

6. Peter.J.Duniam (Flemington,AU):Peter.J.McCallum (The Gap,AU);William.H.Birney

(Nidrea,AU);US Patent no.6,644,202 B1;”Blasting arrangement”; November 11,2003.

7. Claude Pathe (Hery); Rapheal Trousselle (Auxerre);US Patent no.6,173,651 B1;” Method

of Detonator control with electronic ignition module, coded blast controlling unit and ignition

module for its implementation”; January 16,2001.

8. Tatsumi Arakawa (yokohama); Masaaki Nishi; Kazuhiro Kurogi (Nobeoka,Japan);US .

Patent no.5,602,713: “Electronic delay detonator”; February 11,1997

9. Gerald.L.Oswald (New Ringgold);US Patent no.4,445,435;”Electronic delay blasting

circuit”; May 1,1984.


70

10. Kenneth N. Jarrott (Royston park);Eric J. Parker (Vista);US Patent no. 4,632,031;

“Programmable electronic delay fuse”; December 30,1986.

11. Kosuke Miki (Sagamihara); Shiro Hiruta (Tokyo);US Patent no. 4,586,437; “Electronic

delay detonator”; May 6,1986.

12. Lawson J. Tyler ; Paul N. Worsey (Rolla);US Patent no. 4,674,047; “ Integrated detonator

delay circuits and firing console”; June 16, 1987.

13. Andre Guimard (Toulouse);Denis Harle (Rouen);US Patent no. 5,520,114; “ Method of

controlling detonators fitted with integrated delay electronic ignition modules, encoded

firing control and encoded ignition module assembly for implementation purposes”; May 28,

1996.

14. Dirk Hummel (Hennef);Olaf Cramer (Essen);US Patent no. 6,851,369 B2; “Access control

for electronic blasting machines”; February 8, 2005.

15. Developments with Electronic Detonators by John T. Watson.

Websites:

www.uspto.gov

www.drdo.org

www.dtic.mil

www.epanorama.com

www.atmel.com

www.alldatasheet.com

www.i-konsytem.com

www.freepatentonline.com

Reference books: -

The 8051 microcontroller and embedded systems – Mazidi & Mazidi

The 8051 microcontroller-Architecture, programming and interfacing - Kenneth.J.Ayala

http://www.uspto.gov/

http://www.drdo.org/

http://www.dtic.mil/

http://www.epanorama.com/

http://www.atmel.com/

http://www.alldatasheet.com/

http://www.i-konsytem.com/

http://www.freepatentonline.com/


71

APPENDIX


72

A. PRINTED CIRCUIT BOARDS: -

Fig.A.1. Time setter unit


73

Fig.A.2. Timer unit, Keypad, LCD display


74

B. CIRCUIT COMPONENTS: -

1. TIME SETTER UNIT: -

1.1. AT89C51RD2 microcontroller

AT89C51RD2/ED2 is a high performance CMOS Flash version of the 80C51 CMOS single

chip 8-bit microcontroller. It contains a 64-Kbyte Flash memory block for code and for data. The

64-Kbytes Flash memory can be programmed either in parallel mode or in serial mode with the

ISP capability or with software. The programming voltage is internally generated from the

standard V CC pin.

The AT89C51RD2/ED2 retains all of the features of the Atmel 80C52 with 256 bytes of

internal RAM, a 9-source 4-level interrupt controller and three timer/counters. The

AT89C51ED2 provides 2048 bytes of EEPROM for nonvolatile data storage. In addition, the

AT89C51RD2/ED2 has a Programmable Counter Array, an XRAM of 1792 bytes, a Hardware

Watchdog Timer, SPI interface, Keyboard, a more versatile serial channel that facilitates

multiprocessor communication (EUART) and a speed improvement mechanism (X2 Mode). The

fully static design of the AT89C51RD2/ED2 allows to reduce system power consumption by

bringing the clock frequency down to any value including DC, without loss of data.

Pin configuration: -

Fig.B.1. Pin configuration of AT89C51RD2


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1.2. Keypad

The keypad has 16 keys in a 44 matrix form. It is connected with the port 2 of the

microcontroller. The keypad is interfaced with a latch IC 74LS373 and a buffer IC 74LS541.The

keys are used to enter the password and then to feed the delay time. The delay will be entered as

4-digit number e.g. 25ms should be entered as 0025.

Fig.B.2 44 keypad

1.3. LCD display

It enables the system to talk with the user. The LDC display used here is a 16 character 2-line

LCD module. It displays all the functions which are to be programmed. It is connected with the

port 0 of the microcontroller.

Fig.B.3.162 LCD display


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1.4. Power Supply Unit

The power supply is obtained from regulator IC 7805 which is a three pin device, connected

along with the coupling capacitors. It gives +5V output. This output voltage is common for all

the chips on the board. 7805 gets its power supply either from a 9V battery or any external power

supply unit.

Fig.B.4. Regulator IC 7805

1.5. MAX 232 IC

MAX 232 is used for the serial communication between the microcontrollers of the time

setter and timer unit. The communication is needed for sending the delay time to the timer unit.

This is possible through DB9 connector. In order to receive the acknowledge signal from the

timer, 2-way communication can be employed.

Fig.B.5. MAX 232 IC


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2. TIMER UNIT: -

2.1. ATtiny 12 microcontroller

The ATtiny11/12 is an 8-pin, low-power CMOS 8-bit microcontroller based on the AVR

RISC architecture. By executing powerful instructions in a single clock cycle, the ATtiny11/12

achieves throughputs approaching 1 MIPS per MHz, allowing the system designer to optimize

power consumption versus processing speed.

The AVR core combines a rich instruction set with 32 general-purpose working registers. All the

32 registers are directly connected to the Arithmetic Logic Unit (ALU), allowing two

independent registers to be accessed in one single instruction executed in one clock cycle. The

resulting architecture is more code efficient while achieving throughputs up to ten times faster

than conventional CISC microcontrollers.

Pin configuration: -

Fig.B.6. Pin configuration of ATtiny 12

2.2. MAX 232 IC

MAX 232 is used for the serial communication between the microcontrollers of the time setter

and timer unit. The communication is needed for sending the delay time to the timer unit. This is

possible through DB9 connector. In order to receive the acknowledge signal from the timer, 2-

way communication can be employed.

Fig.B.7. MAX 232 IC

Programmable Delay Detonator

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