NON-EXPLOSIVE PROGRAMMABLE ELECTRONIC INITIATION SYSTEM FOR ROCK BLASTING

Abstract

The present development includes a non-explosive, programmable electronic initiation system, whose objective is to initiate rock blasting in a controlled and safe manner. Its application is mainly in the area of Mining and Civil Works. This system solves a sensitive issue in the industry, such as the non-activation of the devices at the time of blasting (shots left behind) and reduces the risks of operation in the fragmentation work, providing continuity to field work. The above is based on the fact that this system allows precise operation times for vibration control, through previously defined delays, immediately identifying non-operational initiators due to line or connection failures; since there are no explosive components, they can be programmed remotely if so required by the user; finally, each initiator is programmed to be unique and unrepeatable.

Claims

1. A Programmable Non-Explosive Electronic Initiator [07] for a rapidly expanding metal mixture and/or plasma, the electronic initiator comprising: a capsule, the capsule containing attached two types of rapidly expanding metal mixture, a first type [13] having an activation temperature above 1000 C. and a second type [15] having an activation temperature above 1200 C.; wherein the capsule corresponds to a container tube or sleeve [16] closed with a sealing plug [17]; wherein the capsule receives the communication protocol based on voltage modulation [03], by means of a communication and power line [02a and 02b] using a bidirectional serial algorithm from an external command equipment [01]; a C7 capacitor [8][21] having a voltage requirement under 35v, which by means of a controlled discharge on the filament [12][30] produces the filament to glow; wherein the filament [12][30] is supported on a solid base [11] covered with the first type of fast expanding metallic mixture [13], wherein the filament and the solid base are inserted in a shrink sleeve [14] which holds them together, wherein the shrink sleeve [14] is contained inside the capsule container [16] which in turn contains the second type of rapidly expanding metallic mixture [15]; a PCB printed circuit board [10] having a PCB printed circuit [9] configured to control the discharge with a delay between 1 ms to 64,000 ms and testing so that the circuit may be checked prior to ignition.

2. The electronic initiator according to claim 1, wherein the PCB printed circuit board [9] comprises; an IC1 microprocessor [28] having a unique and unrepeatable identification code (ID), which receives the bidirectional communication coming from the external command equipment [01] and processes the different commands to activate the Programmable Non-Explosive Electronic Initiator [07], wherein the Microprocessor IC1 [28] further comprises a non-volatile EEPROM memory configured to store the unique and unrepeatable identification code (ID), the delay parameters, and an internal oscillator, wherein a PIN of the Microprocessor IC1 [28] operates as input for signal processing functioning as initial and final charge sensor of Capacitor C7 [8][21] and sensing the continuity of Filament [30]; a flash microcontroller, a programming unit [28F] of RAM memory [44] belonging to Microprocessor IC1 [28]; a Capacitor C4 [19] that maintains the stability and autonomy of the input voltage to the Microprocessor IC1 [28] once the trigger command is received; and an External Oscillator Q1 [25] connected to the Microprocessor IC1 [28] of lower oscillation frequency than the internal oscillator of the latter to deliver the pulses to a TIMER [28A] of the Microprocessor IC1 [28].

3. The Electronic Initiator according to claim 1, wherein an I/O PORT PIN C0 in the Microprocessor IC1 [28], which is connected to two resistors R5 and R10, activates the transistor T3 producing the charge of the Capacitor C7 [8][21].

4. The electronic initiator, according to claim 1, wherein the Capacitor C4 [19] has a high capacitance with ranges above 300 F of tantalum, maintaining the stability of the input voltage to the Microprocessor IC1 [28] as well as the energy reservoir to allow the Microprocessor IC1 to remain autonomous [28] through the programmed delay period once the trigger has been activated and the Communication and Power Line [02A and 02B] are interrupted.

5. The electronic initiator, according to claim 1, wherein the External Oscillator Q1 [25] has a frequency of 32,000 Hertz, a lower frequency than the internal oscillator of Microprocessor IC1 [28]; wherein the External Oscillator is connected to Microprocessor IC1 [28], wherein a command deactivates the internal oscillator of Microprocessor IC1 [28] and activates the low frequency External Oscillator Q1 [25], wherein the activation of External Oscillator Q1 [25] reduces the frequency and power consumption of Microprocessor IC1 [28] by 250 to 500 times, wherein the External Oscillator Q1 [25] in combination with the activation of the sleep function of the Microprocessor IC1 [28], reduces power consumption from mA to nA, thus achieving the maximum programmable delay time of 64,000 milliseconds.

6. The electronic initiator, according to claim 5, wherein the External Oscillator Q1 [25] is the agent emitting pulses for the TIMER1 to count said pulses and determine the time, this information is stored and is available for reading by means of Software, where 32 pulses emitted by External Oscillator Q1 [25] and read by the TIMER1 are equivalent to 1 millisecond.

7. The Electronic Initiator, according to claim 1, wherein due to the low energy consumption achieved with the activation of the External Oscillator Q1 [25], the activation of the sleep function of the Microprocessor IC1 [28] and the autonomy of the Capacitor C4 [19], achieve a sleep state of more than 64,000 milliseconds, where the delay time is programmable from each Programmable Non-Explosive Electronic Initiator [07] and limited to a range between 1 and 64,000 milliseconds.

8. The Electronic Initiator, according to claim 1, wherein the Filament [30], comprises a spiral shape, whose incandescence is capable of reaching a high temperature that activates a Rapidly Expanding Metal Mixture [13] adhered to it, through the complete discharge of the Capacitor C7 [21].

9. The Electronic Initiator, according to claim 1, wherein the Programmable Non-Explosive Electronic Initiator [07], the communication and power line [02a and 02b] and the command equipment [01] communicate through a square wave frame, keeping the Programmable Non-Explosive Electronic Initiator(s) [07] synchronized in time.

10. The Electronic Initiator, according to claim 2, wherein the capacitor C7 [21] of 35V and with a Resistor R9 [21] connected in series with said Capacitor C7 [21], allows a slow charge of Capacitor C7 [21], implying an independent low current consumption by each Programmable Non-Explosive Electronic Initiator [07].

11. The Electronic Initiator, according to claim 1, wherein the number of units connected in parallel of the Programmable Non-Explosive Electronic Initiator(s) [07] is limited to the current consumption of each Programmable Non-Explosive Electronic Initiator [07] multiplied by the number of Programmable Non-Explosive Electronic Initiator(s) [07] connected to the Communication and Power Line [02A and 02B], wherein this value is not greater than the current capacity delivered by the Command Equipment [01], wherein the maximum number of units connected in parallel is directly proportional to the consumption of each Programmable Non-Explosive Electronic Initiator(s) [07] ranging from 10 to 30 milliAmperes per unit, and wherein the activation of the maximum number of Programmable Non-Explosive Electronic Initiator(s) [07] units, connected in parallel, requires between 24V and 35V.

12. A testing and exothermic reaction process of the Programmable Non-Explosive Electronic Initiator [07] of claim 1, wherein the process comprises the following steps: i) checking the communication failure between the Command Equipment [01] and the Programmable Electronic Non-Explosive Initiator(s) [07]; ii) checking the initial charge of Capacitor C7 [8][21], where the final charge of Capacitor C7 [8][21] is checked, and in case of error, transistor T4 [22] is activated and capacitor C7 [21] is forced to ground (Vss or GND); iii) checking the continuity of the Filament [30], where, in case of error, the transistor T4 [22] is activated and forces the discharge to ground (Vss or GND) of the capacitor C7 [21]; iv) checking the delay time value programmed in the EEPROM memory of Microprocessor IC1 [28]; v) once stages i, ii, iii and iv have been checked, a command [6] initiates the following: vi) disconnecting all the interrupts of Microprocessor IC1 [28] to avoid an early awakening of the sleep function; vii) disconnecting the load of Capacitor C7 [21], so that it maintains its charge at maximum while Microprocessor IC1 [28] is in sleep mode and TIMER1 counts down; viii) retrieving information related to the delay time stored in the non-volatile EEPROM memory of Microprocessor IC1 [28] and loading the programmed delay time into the TIMER1 counter (Command 2); ix) enabling the sleep function of Microprocessor IC1 [28] and only TIMER1 is kept running to start the delay time countdown; x) starting the delay time countdown; xi) once the countdown reaches 0, the IO PORT C5 is lifted, activating through resistor R8 transistor T2 which, through the stored energy of capacitor C7, discharges all its energy to ground passing through the filament (30) causing it to glow; xii) activating the first rapidly expanding metallic mixture [13] through the filament being compressed with it by means of the Shrink Sleeve [14], with a temperature rise sufficient to activate the second rapidly expanding metallic mixture [15]; and xiii) causing exothermic reaction between the Programmable Non-Explosive Electronic Initiator [07] and the rapidly expanding metal mixture and/or plasma.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0062] FIG. 1A depicts an arrangement of elements of the present system using a single parallel Communication and Power line for a single Programmable Non-Explosive Electronic Initiator and an RFID reader that reads the unique identifier code ID of the Programmable Non-Explosive Electronic Initiator.

[0063] FIG. 1B depicts the present system using a single parallel Communication and Power line for four or more Programmable Non-Explosive Electronic Initiators.

[0064] FIG. 2A is a diagram representing voltage waves showing the beginning of a bidirectional communication, where the Voltage Modulation sent consists of a constant square wave.

[0065] FIG. 2B is a first diagram representing voltage waves showing a bidirectional communication protocol with a transmission rate of 2,400 bits per second that is used in the Communication and Power Line.

[0066] FIG. 2C is a second diagram representing voltage waves showing the bidirectional communication protocol with a transmission rate of 2,400 bits per second that is used in the Communication and Power Line.

[0067] FIG. 3A is a first schematic representation of a Printed Circuit Board (PCB) of the present disclosure.

[0068] FIG. 3B is a second schematic representation of a Printed Circuit Board (PCB) of the present disclosure.

[0069] FIG. 3C shows a detail of the interaction between a Filament coated with a Rapidly Expanding Metal Mixture, inserted in a Shrink Sleeve, in accordance with aspects of the present disclosure.

[0070] FIG. 4 is a schematic circuit of a Programmable Non-Explosive Electronic Initiator of the present disclosure.

[0071] FIG. 5 is a specification of the CPU programming and feedback described in the schematic circuit of the Programmable Non-Explosive Electronic Initiator of FIG. 4.

[0072] FIG. 6 is a detailed representation of the dynamics generated in a Clock Source Block of the present disclosure.

[0073] FIG. 7 is a diagram of how the square wave with the data is transmitted from the Command Unit to the INT/IO PORT input pin and IO output ports of FIG. 4.

[0074] FIG. 8 is a diagram of the analog information received by the Microprocessor IC1 through the ADC/AN pin in FIG. 4.

[0075] FIG. 9 is a diagram of how Microprocessor IC1 of FIG. 4, through the USART transmission block pin TX, transmits the output data.

DETAILED DESCRIPTION

Operating the Development

[0076] It must be stated that this development is not limited to the particular methodology, compounds, materials, manufacturing techniques, uses, and applications described herein, as these may vary. It should also be understood that the terminology employed herein is used for the sole purpose of describing a particular embodiment, and is not intended to limit the perspective and potential of this invention.

[0077] It should be noted that in the use and method, here, in the statement of claims and throughout the text, the singular does not exclude the plural, unless the context clearly implies so. So, for example, the reference to a use or method is a reference to one or more uses or methods and includes equivalents known to those familiar with the subject matter (the art). Similarly, as a further example, the reference to a step, a stage or a mode is a reference to one or more steps, stages, or modes and may include implied and/or upcoming sub-steps, stages, or modes.

[0078] All conjunctions used should be understood in the least restrictive and most inclusive sense possible. Thus, for example, the conjunction or should be understood in its orthodox logical sense, and not as an or excluding, unless the context or the text expressly requires or indicates it. The structures, materials, and/or elements described must be understood to also refer to those functionally equivalent in order to avoid endless, exhaustive enumerations.

[0079] Expressions used to indicate approximations or conceptualizations should be understood as such, unless the context dictates a different interpretation.

[0080] All technical and/or scientific names and terms used herein have the common meaning given to them by an ordinary person qualified in these matters, unless expressly indicated otherwise.

[0081] Methods, techniques, elements, compounds, and compositions are described, although similar and/or equivalent methods, techniques, compounds, and compositions to those described may be used or preferred in practice and/or when testing this invention.

[0082] All patents and other publications are incorporated as references, for the purpose of describing and/or reporting, for example, methodologies described in such publications, which may be useful in connection with this invention.

[0083] These publications are included only for the information they contain prior to the filing date of this patent application.

[0084] Nothing in this regard should be considered an admission or acceptance, rejection or exclusion, of the entitlement of the authors/inventors to be considered as such, or of such publications being backdated pursuant to previous ones, or for any other reason.

[0085] In order to provide clarity to the present development, the following concepts will be defined: [0086] Delay: The concept of delay or delay time in the present development refers to the assignment of a countdown delay period measured in milliseconds (ms) that determines the firing sequence in a blast. Each detonator is assigned a previously defined time period (between 1 and 64,000 milliseconds). [0087] Misfires: The concept of misfires for the present development refers to the complete or partial misfire of one (or more) capsule comprised in the firing sequence in a blast. It is a high-risk unintended consequence, in which product debris that can be activated by any mechanical effect during the excavation, milling or crushing stages of the mining process. [0088] Microprocessor: The concept of microprocessor used for the present development refers to the set of integrated electronic circuits that carry out the instructions and tasks involved in information processing. The present development requires a Microprocessor with the following features: serial communication, low power consumption (preferably but not restricted to 20 nA in sleep mode), precision internal oscillator (preferably but not restricted to 31 KHz to 32 MHz), feasibility of integrating an external low frequency oscillator (preferably but not restricted to 32 KHz), memory capacity (preferably but not restricted to EEPROM 256 bytes, SRAM 256 bytes) and sufficient input and output ports to perform the functions required (at least 8). Microchip model PIC16LF1824/1828 has been identified as a feasible Microprocessor for executing the commands and programs required in this development. [0089] Communication protocol: a system of rules that allow two or more entities of a communication system to communicate with each other and transmit information. This development refers to the form of bidirectional communication between the Command Equipment [01] and the Non-Explosive Electronic Initiator(s) [07] that maintains the transmission of information and the voltage necessary for the operation of the Non-Explosive Electronic Initiator(s) [07], and which may take place under the bit per second transmission language through voltage pulses. [0090] Filament: In the present development, the filament has a thickness, length and materiality that achieves a balance between capacitance and resistance to avoid it from being cut and achieving the necessary temperature. By way of example and without restricting the scope of this term, this could refer to a tungsten filament of a purity varying between 99.90% and 99.99%, preferably 99.93%, 99.95% and 99.97%, in spiral form with a length varying between 1 and 3 mm, preferably 2 mm, 2.2 mm, 2.5 mm, with a diameter of a range between 0.01 mm and 0.1 mm, preferably 0.01 mm, 0.02 mm, 0.03 mm and with a resistance ranging from 2.5 to 4.5 ohm, preferably 3 ohm, 3.2 ohm, 3.5 ohm, 3.6 ohm, 3.7 ohm, 3.8 ohm and 3.9 ohm. [0091] Safety: The development addresses the precautions to be taken with the different devices, based on their manipulation and how to maintain the inactivation of the initiator through special commands created for such purpose. [0092] Exothermic reaction: This development refers to any chemical reaction that gives off energy, either as light or heat, or, in other words, with a negative enthalpy variation. [0093] Plasma: In the present development, plasma is considered as a rapidly expanding mixture of metallic salts that upon initiation produces a high-temperature exothermic reaction in a confined space. It is a very stable substance, as it does not react to high temperatures, shocks, friction, and high pressures. The reaction is initiated at high temperatures, above 1,000 C.

[0094] In order to operate the present development, a Command Equipment (Console or Master) [01], with the capacity to convert the serial communication into a communication protocol based on Voltage Modulation [03] through a Communication and Power Line (parallel lines) [02A and 02B], a connector [04] that connects said parallel lines with the Non Explosive Programmable Electronic Initiator(s) [07] (FIGS. 1A and 1B) and a RFID Card Reader (Logger) [06] are required.

[0095] Other general requirements for the operation of the Command Equipment [01] consist of, but are not limited to: external power supply (preferably 24V to 36V battery), microprocessor, Micro SD card, Bluetooth system, RFID reader [06], wireless transmission and display with keypad.

[0096] The operation of the development also requires a Communication and Power Line [02A and 02B] consisting of two parallel copper wires, each with a diameter greater than 0.5 millimeters, and a resistance of less than 36 ohm per kilometer. These cables play an essential role, and when used according to the instructions in Table I, they ensure both the reliability in the transmission of Voltage Modulation [03] and communication protocol (FIG. 2), as well as the power received by each Programmable Non-Explosive Electronic Initiator [07].

TABLE-US-00001 TABLE I Electrical Conductor Resistance Maximum Copper Wire Resistance ohm/km at 20 C. Mono or Multipair Diameter Cu (uncoated) ohm Cu (coated) ohm 0.5 36.00 36.70 0.75 24.50 24.80 1 18.10 18.20 1.5 12.10 12.20 2.5 7.41 7.56 4 4.61 4.70 6 3.08 3.11 10 1.83 1.84

[0097] For this development to have a practical use (in the field), it should consider the use of a portion of two rapidly expanding metallic mixtures [13] and [15] (PLASMA) with a formulation similar to the ones mentioned earlier, such as:

2Fe(NO.sub.3).sub.2+12Mn; Patent No. 10-0213577Formula 1:

Fe(NO.sub.3).sub.2+3CuO+6Al; Patent No. 10-0213577Formula 2:

3Ca(NO.sub.3).sub.2+Fe.sub.3O.sub.4+12Al; Patent No. 10-0213577Formula 3:

Fe.sub.2O.sub.3+4Na.sub.2O+BaCO.sub.3+4Mg; Patent No. 10-0213577Formula 4:

Fe.sub.2O.sub.3+NaSO.sub.4+4Al; Patent No. 10-0213577Formula 5:

2Na.sub.2O+Fe.sub.2O.sub.3+3CuO+2Al; Patent No. 10-0213577Formula 6:

2NaClO.sub.4+2CuO+2Al; Patent No. 10-0213577Formula 7:

[0098] It should be understood that, for the use of the present development, the rapidly expanding metal mixtures [13] and [15] will be activated and the expected exothermic reaction will be triggered.

Development Overview

[0099] The present development consists of a Programmable Non-Explosive Electronic Initiator [07], comprising a capsule with two types of rapidly expanding metallic mixture [13] and [15] that allows coupling to a container tube or sleeve [16] and a sealing plug [17](FIG. 3); and that, once it receives the Voltage Modulation [03] and the communication protocol (FIG. 2), by means of commands, the functions that allow reaching the high temperatures required to initiate the chemical reaction are activated, using a low voltage requirement (less than 35V), with a delay system (from 1 ms to 64,000 ms), and with a testing system that allows validation of the circuit prior to ignition.

[0100] An algorithm is programmed and saved in Microprocessor IC1 [28] in order to give functionality to the system. By means of functions and commands, this algorithm recognizes from the input signal, reads input data concerning the oscillator frequency (FIG. 4) [28A], reads data from the filament and capacitor sensors (FIG. 4) [28C], activates the ports (FIG. 4) [28B] of capacitor charging, triggering, capacitor discharging, activation of the serial communication port (FIG. 4) [28E], for sending data through the Communication and Power Line [02A and 02B] to the Command Unit [01], receiving the data through Interrupt (FIG. 4) [28D], and the CPU central processing unit (FIG. 4) [28F], which performs the task of processing all the functions as well as storing the information.

[0101] Each Non-Explosive Programmable Electronic Initiator [07] has a unique and unrepeatable identification (ID), which is recorded at the factory and matches the internal code of the external RFID card [05]. By means of an algorithm, the Command Equipment [01] captures this ID through the serial port via Bluetooth through the RFID reader equipment (Logger) [06] (FIG. 1) and stores it in the MicroSD card belonging to the Command Equipment [01]. The data are available for further use in certain processes.

[0102] The Programmable Non-Explosive Electronic Initiator [07], has a Microprocessor IC1 [28] (FIG. 4), with an Internal Oscillator and a non-volatile EEPROM memory [35](FIG. 5).

[0103] With the Command Equipment [01] activated, and all requirements for operation in order, the Communication and Power Line [02A and 02B] is activated, initiating the Voltage Modulation [03] and the communication protocol (FIG. 2) coming from the Command Equipment [01]. At the beginning of the bidirectional communication, the Voltage Modulation [03] (FIG. 2) sent consists of a constant square wave with a defined amplitude between 24V and 35V (FIG. 2A) and a period of 4.0 ms. The high bit of 4 milliseconds and the low bit of 0.2 milliseconds allow a constant voltage to be maintained (FIG. 2A).

[0104] It is to be understood that the abovementioned Voltage Modulation [03] (FIG. 2) is the one that allows to match the sending of data and energy necessary for the subsequent activation of one (or more) Programmable Non-Explosive Electronic Initiator [07].

[0105] A bidirectional communication protocol (FIGS. 2B and 2C) with a transmission rate of 2,400 bits per second is used in the Communication and Power Line [02A and 02B].

[0106] Data is sent at a communication rate equivalent to 2400 baud from the Command Equipment [01] via the Communication and Power Line [02A and 02B] and is received by the Programmable Non-Explosive Electronic Initiator(s) [07] (FIG. 2C).

[0107] Data is sent over the Communication and Power Line [02A and 02B] from the Programmable Non-Explosive Electronic Initiator(s) [07] and received by the Command Equipment [01] (FIG. 2B). The sending of data from the Programmable Non-Explosive Electronic Initiator [07] to the Command Equipment [01] is determined by a 25 us (microsecond) bit, equivalent to 40,000 baud; data transmission (one byte) is performed on the low bit of the communication line.

[0108] The Programmable Non-Explosive Electronic Initiator input [07], comprises a diode D1 and a Voltage Rectifier D2 [18] (FIG. 4), which are connected to the Communication and Power Line [02A and 02B]. Diode D1 suppresses transient currents and prevents current leakage. The D2 Voltage Rectifier, with voltage inputs between 24V and 35V, transforms alternating current (AC) into direct current (DC) (FIG. 4).

[0109] A Voltage Regulator IC2 [20] receives the voltage from 24V to 35V and the rectified current (DC). This IC2 Voltage Regulator regulates the initial voltage to 5V (FIG. 4).

[0110] For bidirectional communication between the Command Equipment [01] and the Programmable Non-Explosive Electronic Initiator [07], two voltage divider resistors R1 and R2 [24] are connected to the system input of the Programmable Non-Explosive Electronic Initiator [07], which lower the voltage from 24V-35V to 5V, thus adjusting to the operating level of the Microprocessor IC1 [28]. In addition, R1 operates with resistance between 90 and 170 kOhm, preferably 110 kOhm, preferably 120 kOhm and preferably 130 kOhm and R2 operates with resistance between 15 kOhm and 25 kOhm, preferably 110 kOhm, preferably 120 kOhm and preferably 130 kOhm. The square wave with the data is then transmitted from the Command Unit [01] to the INT/IO PORT input pin [41] (FIG. 7) of the IC1 Microprocessor [28] and converted into bytes using an algorithm.

[0111] In response, the Microprocessor IC1 [28] through the EUSART transmission block [28E] (FIG. 4) pin TX [43] (FIG. 9), transmits the output data. The output data are inserted through a transistor T1 and two resistors R3 and R4 [23] in the Communication and Power Line [02A and 02B]. The response data is then sent to the Command Team [01] for processing (FIG. 2B).

[0112] Two diodes D4 and D5 are connected to the 5V voltage input [19]. In this stage of the circuit, the input voltage 5V is reduced to 3.6V, which is necessary to operate the IC1 microprocessor [28]. Diodes D4 and D5 [19] suppress transient currents and prevent current leakage.

[0113] A 6.3V, 470 pF Capacitor C4 [19], connected to diodes D4 and D5 [19] and to the voltage input of Microprocessor IC1 [28], keeps the 3.6V input voltage stable. Capacitor C4 [19] is an energy reservoir that is continuously charged. It is essential to note that this device will be the power source for Microprocessor IC1 [28] and will keep it active for up to 64,000 milliseconds, once the Communication and Power Line [02A and 02B] is interrupted. The discharge time of this capacitor must be greater than the programmed delay time; this point is addressed in more depth when describing the operation of the External Oscillator [25] (FIG. 4) and OSC [36] (FIG. 6).

[0114] Two resistors R6 and R7 [26] divide the voltage between Ground (GND), Filament [30] and Capacitor C7 [08] (FIGS. 3 and 4) of 35V. Filament [30] is a Tungsten spiral with a length ranging from 1 to 3 mm, preferably 2 mm, 2.2 mm, 2.5 mm, with a diameter ranging from 0.01 mm to 0.1 mm, preferably 0.01 mm, 0.02 mm, 0.03 mm and with a resistance ranging between 2.5 and 4.5 ohm, preferably 3 ohm, 3.2 ohm, 3.5 ohm, 3.6 ohm, 3.7 ohm, 3.8 ohm and 3.9 ohm.

[0115] As a safety measure, a transistor T4 [22] (FIG. 4) connected to a series resistor R12 (current limiter), which in turn is connected to ground (Vss or GND), maintains the Filament [30] and the Capacitor C7 [21] with a voltage lower than 1V. The Transistor T4 [22] is deactivated by issuing a command (Command 5) to start the charging process of Capacitor C7 [21], prior to firing. Once all the elements of the circuit have been activated, if any fault is detected, through a command (Command 6), this Transistor T4 [22] discharges to ground (Vss or GND) the Capacitor C7 [21], reducing the voltage of the Capacitor C7 [21] to a value lower than 1 V and preventing the Filament [30] from having the necessary voltage to ignite and activate the metallic fast-expansion mixture.

[0116] Filament [30] is connected to Capacitor C7 [21] (initial charge 0V) and transistor T2 [27]. Once the Trigger Command (Command 7) has been activated, the I/O PORT pin C5 [28B] (FIG. 4) activates the transistor T2 [27] to discharge the Capacitor C7 [21] in the Filament [30], causing it to glow.

[0117] Resistor R9 [21] limits the input current to a value ranging between 2 and 3 milliamps, this allows a slow charging of Capacitor C7 [21] and a minimum current consumption. Diode D3 [21] prevents current leakage from Capacitor C7 [21].

[0118] The resulting analog voltage between resistors R6 and R7 [26] (DC) enters the ADC/AN pin [28C] (FIG. 4). The analog information received by the Microprocessor IC1 [28] through the ADC/AN pin [42] (FIG. 8) is converted to digital for sensor readout.

[0119] The arrangement of the elements, together with the processes and commands activated by means of an algorithm, allow for establishing a Test System based on the values provided by the sensor configured on the ADC/AN pin [42] (FIG. 8) belonging to Microprocessor IC1 [28] (FIG. 4).

[0120] The Test System is powered by the sensor data configured on the ADC/AN pin [42](FIG. 8). The data obtained are analyzed by means of an internal algorithm of Microprocessor IC1 [28].

[0121] The Performance Test System is activated via Command 3 (described below) and consists of the following tests: [0122] Communication Check: [0123] Using an algorithm, a data frame is sent to each (unique) ID and a response is expected. The maximum waiting time is 150 milliseconds. [0124] A response time>150 milliseconds implies a communication error. [0125] Filament Check [0126] By means of an algorithm, a voltage calculation yields a given result in absolute units. A reading with an absolute value of 0 (zero) in the sensor means that the Filament [30] has been severed. [0127] Absolute Value=0 means Unusable Initiator [0128] Capacitor C7 Initial Status Check [21]: [0129] At system startup, a transistor T4 [22] (FIG. 4) connected to a resistor R12 [22] is activated to connect the positive output of capacitor C7 [21] to ground (Vss or GND) and maintains the capacitor load at a voltage below 1 V. The check of the initial state of capacitor C7 [21] consists of measuring the voltage of capacitor C7 through sensor [28C]. The sensor reads the voltage data from Capacitor C7 [21] and stores it in a 10-bit variable in Microprocessor IC1 [28] equivalent to a given number of 1024 parts. Considering that the initial voltage is in a range between 24V and 35V, one part equals a range between 0.023V and 0.034V; then a range between 30 and 43 parts equals a voltage of less than 1V. The reading after this milestone should be less than 1 V. A reading greater than this value means that either Capacitor C7 [21] is defective or Transistor T4 [22] is defective. [0130] Voltage Capacitor C7 [21]1V implies that the Initiator is Unusable. [0131] Capacitor C7 Initial Charge Status Check [31]: [0132] Transistor T4 [22] connected to resistor R12 [22] is deactivated and left ungrounded. Transistor T3 [29] is activated and through resistors R5 and R10 [29], which begins charging Capacitor C7 [21]. The sensor reads and stores data regarding the state of charge of Capacitor C7 [21] every 30 milliseconds during the 30 seconds of the programmed charge. The data is stored in a 10-bit variable in the IC1 microprocessor [21] equivalent to a given number of 1024 parts. At the end of the charging period (30 s), the reading of Capacitor C7 [21] should be greater or equal to 800 parts, a fraction that indicates sufficient voltage to generate the required glow in the filament [30]. [0133] Voltage Capacitor C7 [21]<800 parts implies that the Initiator is Unusable. [0134] Programmed Delay Verification: [0135] By means of an algorithm and through a command (Command 3), data regarding the programmed delay is sent from the Command Unit [01] to the Programmable Non-Explosive Electronic Initiator [07] and stored in the non-volatile EEPROM memory of Microprocessor IC1 [28]. The Programmable Non-Explosive Electronic Initiator [07] uses an algorithm to verify that the data sent by the Command Unit [01] is equal to the data received by the Microprocessor IC1 [28]. Microprocessor IC1 [28] sends a response to the Command Unit [01]. [0136] The programmed waiting time is 150 milliseconds. [0137] A response time>150 milliseconds implies a communication error. [0138] If the response data concerning the delay is identical to the data sent by the Command Team [01], an acknowledgement code (ACK) is received. [0139] If the response data concerning the delay is different to the data sent by the Command Team [01], an error code is received. [0140] External Oscillator Status Check [25] and Frequency Change for sleep mode: [0141] At system startup, the External Oscillator [25] is activated and the pulses per second emitted are read. These pulses must coincide with the frequency of 32 KHz. Once the related data has been recorded in the non-volatile EEPROM memory of Microprocessor IC1 [28], the External Oscillator [25] is deactivated. [0142] Recorded pulses of the External Oscillator [25]=32,000 per second [0143] If the response data concerning pulses is different to 32,000 the Command Team [01], an error code is received.

[0144] Microprocessor IC1 [28], which has an internal oscillator of preferably 16 MHz [28A](FIG. 4)although higher frequency alternatives are not excluded-, has a power consumption of approximately 2 mA (milliamperes). FIG. 6 is a detailed representation of the dynamics generated in Clock Source Block [28A] pertaining to FIG. 4.

[0145] This development includes a 32 kHz External Oscillator Q1 [25] (FIG. 4) connected to Microprocessor IC1 [28], whose objective is to reduce power consumption by lowering the system frequency from 16 MHz to 32 KHz.

[0146] The Filament [30] (FIG. 4) is made by spiral shaped Tungsten wire with a with length ranging from 1 to 3 mm, preferably 2 mm, 2.2 mm, 2.5 mm, with a diameter ranging from 0.01 mm and 0.1 mm, preferably 0.01, 0.02, 0.03 and with a resistance ranging from 2.5 to 4.5 ohm, preferably 3 ohm, 3.2 ohm, 3.5 ohm, 3.6 ohm, 3.7 ohm, 3.8 ohm and 3.9 ohm.

[0147] In FIG. 3, which describes the Printed Circuit Board (PCB) [10], the Filament [12](the same one shown as Filament [30] in FIG. 4, schematic circuit) is supported on a solid base [11], covered with a Rapidly Expanding Metal Mixture [13], both inserted in a Shrink Sleeve [14]. It is the Shrink Sleeve [14] that keeps the Filament [12] bound to the Rapidly Expanding Metal Mixture [13]. The Shrink Sleeve [14] is encased by a Capsule container [16] which in turn contains another quantity of a Rapidly Expanding Metal Mixture [15], sealed with a plug [17].

[0148] An External Oscillator Q1 [25] of lower frequency than the internal oscillator of the Microprocessor IC1 [28], emits pulses that are read by TIMER1 [37] (FIG. 6). The count of these pulses, performed by TIMER1, is stored and made available for reading by means of an algorithm.

[0149] Using an algorithm, the operation of the External Oscillator Q1 [25] is automatically enabled once the internal oscillator of the Microprocessor IC1 [28] becomes disabled.

[0150] When the internal oscillator of Microprocessor IC1 [28] is turned off and the External Oscillator Q1 [25] starts to operate, the TIMER1 [37] (FIG. 6) of Microprocessor IC1 [28] can read the pulses emitted by it and use an algorithm to associate their equivalence in time.

[0151] The delay time is defined in the field and before issuing the Fire command. The defined delay time is programmed in the Programmable Non-Explosive Electronic Initiator(s) [07] through the Command Set [01]. The data related to the programmed delay time is stored in the non-volatile EEPROM memory of the Microprocessor IC1 [28] of each Programmable Non-Explosive Electronic Initiator [07].

[0152] The delay time of each Programmable Non-Explosive Electronic Initiator [07] is limited by three characteristics associated with different functionalities.

[0153] Capacitor C4 [19] (FIG. 4) plays the role of external battery of Microprocessor IC1 [28] after the line break; the charge autonomy of Capacitor C4 [19] is decisive for the maximum operating time of Microprocessor IC1 [28] once the Fire command (Command 7) is activated and the Communication and Power Line [02A and 02B] is cut.

[0154] The 32 kHz External Oscillator Q1 [25] [25] emits 32,000 pulses per second, these are counted by TIMER1 [37] (FIG. 6) of Microprocessor IC1 [28]. These pulses use an algorithm to time them and count down to the programmed delay time.

[0155] Microprocessor IC1 [28] has a sleep mode function, which is activated by an instruction. When entering sleep mode, the TIMER1 oscillator of Microprocessor IC1 [37] is not affected and the peripherals operating from it can continue to operate in sleep mode (FIG. 6); the existence of an External Oscillator Q1 [25], allows to use the sleep function of the IC1 Microprocessor [28] and substantially reduces its power consumption; note that, even though the sleep function could be activated with the internal oscillator of the IC1 Microprocessor [28], its power consumption is 600 nA. Using the External Oscillator Q1 [25] and having activated the sleep functionality, this consumption is 20 nA.

[0156] Due to the low power consumption obtained with the activation of the External Oscillator Q1 [25], we may achieve a sleep state of more than 64,000 milliseconds due to the activation of the sleep function of the Microprocessor IC1 [28] and the autonomy of the Capacitor C4 [19].

[0157] All in all, the programmable delay time of each Programmable Non-Explosive Electronic Initiator [07] is limited to a range between 1 and 64,000 milliseconds.

[0158] When the programmed delay time (Command 2) is reached, Microprocessor IC1 [28] is interrupted internally, deactivating the sleep mode and activating the other functions required to complete the final firing.

[0159] The activation of Fire (Command 6), causes the following actions: [0160] a) All the interrupts of Microprocessor IC1 [28] are disconnected to avoid an early awakening of the sleep function. [0161] b) The load of Capacitor C7 [21] is disconnected, so that it maintains its charge at maximum while Microprocessor IC1 [28] is in sleep mode and TIMER1 counts down. [0162] c) Information related to the delay time stored in the non-volatile EEPROM memory of Microprocessor IC1 [28] is retrieved and the programmed delay time is loaded into the TIMER1 counter (Command 2). [0163] d) The sleep function of Microprocessor IC1 [28] is enabled and only TIMER1 is kept running to start the delay time countdown. [0164] e) The delay time countdown starts.

[0165] Once the delay time has elapsed, Capacitor C7 [21] is enabled; at that moment Transistor T2 (NPN) [27] and its Resistor R8 [27] are enabled to discharge all the energy accumulated in Capacitor C7 [21] on the Filament [30] (FIG. 4).

[0166] The Filament [30] then begins to glow, generating a temperature of more than 1,200 C. due to the capacitance of Capacitor C7 [21] of between 24V and 35 V and a current of approximately 0.250 A, which activates the Rapidly Expanding Metal Mixture [13] (FIG. 3). This exothermic reaction reaches a temperature greater than 1,200 C., which activates the Rapidly Expanding Metal Mixture [15].

Processes

[0167] The Programmable Non-Explosive Electronic Initiator [07] performs the processes described below: [0168] Process 1: The input voltage (24V to 35V) of the Programmable Non-Explosive Electronic Initiator [07] is rectified by means of two capacitors, C1 and C2 [18], a diode D1 and a bridge rectifier D2 [18]. [0169] Process 2: Capacitor C3 [20] keeps the input voltage stable (24V and 35V). The voltage regulator IC2 [20], lowers the input voltage (24V and 35V) to 5V, the input voltage for diodes D4 and D5 [19]. [0170] Process 3: The data enters the Programmable Non-Explosive Electronic Initiator [07] through resistors R1 and R2 [24] (FIG. 04). These resistors filter (separate) the byte frame associated with the incoming data and reduce its input voltage (between 24V and 35V) to the level required by the IC1 microprocessor [28] (between 3.3V and 5.0V). [0171] Process 4: Two diodes D4 and D5 [19] are placed on the voltage input line to the IC1 microprocessor [28]. These components regulate the voltage to the one required by the IC1 microprocessor [28] (3.6V) and stop the current leakage. Also, a 470 uF Capacitor C4 [19] is placed on the input voltage line to the IC1 Microprocessor [28], which keeps the input voltage stable (3.6V). Capacitor C4 [19] also fulfills the role of an energy accumulator. [0172] Process 5: Microprocessor IC1 [28] has a PIN configured as a sensor. The sensor is connected to two resistors R6 and R7 [26], which play the role of voltage divider, between Capacitor C7 [21], Filament [30] and ground (VSS).

[0173] The sensor [28C] (FIG. 4) reads the data resulting from the Filament continuity check [30] (Command 3). The resistance value is expected to be between 2.5 and 4.5 ohm.

[0174] Using an algorithm, the IC1 microprocessor sensor [28] reads the initial charge state of Capacitor C7 [21]. The first sampling is expected to be less than 1V (Command 3). [0175] Process 6: Microprocessor IC1 [28] deactivates Transistor T4 [22], activates the PIN connected to Transistor T3 [29] through Resistors R10 and R5 [29]. This allows the charging of Capacitor C7 [21] to be initiated. The charging process of Capacitor C7 [21] is programmed for 30 seconds. [0176] Process 7: The IC1 Microprocessor sensor [28] records charge voltage data every 30 milliseconds during the 30 seconds of charging Capacitor C7 [28]. The generated data are stored in a non-volatile EEPROM memory of the IC1 microprocessor [28]. The data will be processed via Command 3, indicated further below. [0177] Process 8: Capacitor C7 [21] is connected to the rectified power line (Process 1). Resistor R9 [21] and diode D3 [21] limit the system load. A slow charging of Capacitor C7 [21] (30 sec) and a current consumption between 2 and 3 milliamps is generated. [0178] Process 9: Connected to Microprocessor IC1 [28], External Oscillator Q1 [25] and Capacitors C5 and C6 [25] keep the 32 kHz oscillation stable. [0179] Process 10: The output Transistor T1 [23] and Resistors R3 and R4 [23] send the response frame once the commands (indicated below) have been processed through the bidirectional communication protocol (FIG. 2). [0180] Process 11: Microprocessor IC1 [28] activates transistor T2 [27] through Resistor R8 [27]. Capacitor C7 [21] discharges through the Filament [30], causing the Filament [30] to glow. [0181] Process 12: The glowing Filament [30] reaches a temperature above 1,000 C. and activates the Rapidly Expanding Metal Mixture [13] (FIG. 3). [0182] Process 13: The exothermic reaction of the activation of the Rapidly Expanding Metal Mixture [13] allows reaching a temperature of 1,200 C and activates the Rapidly Expanding Metal Mixture [15].

Commands

[0183] Command 1: Records the ID, the RFID identifier code [05], in the non-volatile EEPROM memory of the IC1 microprocessor [28], which uniquely identifies a Programmable Non-Explosive Electronic Initiator [07].
Command 2: It saves in the non-volatile EEPROM memory of Microprocessor IC1 [28] the programmed delay time, which varies between 1 millisecond and 64,000 milliseconds.
Command 3: Query ID. It diagnoses the current functionality, except for Command 7 (Fire). [0184] Diagnosis 1: An algorithm is used to test the response time of the Programmable Non-Explosive Electronic Initiator [07]. If the response time exceeds a programmed time limit (100 milliseconds), it responds with an error code. [0185] Diagnosis 2: A sensor is used to check that the charge in Capacitor C7 [21] from 470 uF to 2,200 uF is less than 1 V (Volt). In case of failure, it responds with an error code. In case of error, transistor T4 [22] is activated and forces capacitor C7 [21] to ground (Vss or GND). [0186] Diagnosis 3: A sensor is used to check that the filament [30] has continuity between 2.5 and 4.5 ohm. In case of failure, it responds with an error code. In case of error, transistor T4 [22] is activated and forces capacitor C7 [21] to ground (Vss or GND). [0187] Diagnosis 4: An algorithm is used to retrieve the data associated with the programmed delay stored in the non-volatile EEPROM memory of the IC1 microprocessor [28]. The data is checked to ensure that it matches the data to the programmed delay time sent by the Command Equipment [01]. In case of failure, it responds with an error code. [0188] Diagnosis 5: An algorithm is used to retrieve the data associated with the frequency of the External Oscillator [25], stored in the non-volatile EEPROM memory of Microprocessor IC1 [28] at the start of the system. If the register shows an error, transistor T4 [22] is activated and forces capacitor C7 [21] to discharge to ground (Vss or GND).
Command 4: Allows change of location of one (or more) Programmable Non-Explosive Electronic Initiator [07]. Allows to modify the delay assignment of one (or more) Programmable Non-Explosive Electronic Initiator [07]. Allows manual reprogramming of one (or more) Programmable Non-Explosive Electronic Initiators [07].
Command 5: Preparation before firing. Disable Transistor T4 [22] to exit the grounded state. Enables Transistor T3 [29] to proceed with charging Capacitor C7 [21] over a 30 second time period; reads and stores the charge data of Capacitor C7 [21] every 30 milliseconds during the 30 second charge. Stored data is available for reading in a variable of Microprocessor IC1 [28]. Disables the internal oscillator (16 Mhz) of Microprocessor IC1 [28] and enables the External Oscillator [25] (32 KHz).

[0189] At this point, the user must repeat Command 3 to check again that the system is operational including the status change of Capacitor C7 [21].

Command 6: Safety measure in case of any failure. If Command 5 fails, it responds with an error code, Transistor T4 [22] is activated, connecting Capacitor C7 [21] to ground and discharging it.
Command 7: Fire. Disables external interrupts of the microprocessor [28]. Disables the charging of Capacitor C7 [21]. TIMER1 is loaded with the data related to the delay time. Activates the sleep function of Microprocessor IC1 [21]. Enables countdown of the assigned delay time of the Programmable Non-Explosive Electronic Initiator [07]. At the end of the countdown assigned to the programmed delay time, activates Capacitor C7 [21]. Activates I/O output PORT C5 [40] (FIG. 7) of Microprocessor IC1 [28] and Transistor T2 [27].

LISTING OF REFERENCE NUMBERS

[0190] In order to better describe the figures, below is a list of all the items shown in them: [0191] [01] Command Equipment (Console or Master) [0192] [02A] Communication and Power Line [0193] [02B] Communication and Power Line (VSS or GND) [0194] [03] Voltage Modulation [0195] [04] Connector [0196] [05] External RFID card [0197] [06] Logger, RFID Reader [0198] [07] Programmable Non-Explosive Electronic Initiator [0199] [08] Capacitor C7 [0200] [09] PCB Printed Circuit Board [0201] [10] PCB Printed Circuit Board Card [0202] [11] Solid filament base [0203] [12] Filament (FIG. 4) [30] [0204] [13] First metallic mixture [0205] [14] Shrink Sleeve [0206] [15] Second metallic mixture [0207] [16] Container capsule [0208] [17] Container capsule plug [0209] [18] D2, C1, C2, D1 Voltage Rectifier Block [0210] [19] IC1, D4, D5, C4 Microcontroller Voltage input block [0211] [20] IC2, C3, Voltage Regulator Block [0212] [21] C7, D3, R9 Capacitor charging and discharging block [0213] [22] C7, R11, R12 Capacitor Discharge Block [0214] [23] T1, R3, R4 data to communication line transmitter block [0215] [24] Voltage divider block with data to block 28D (INT), R1, R2 [0216] [25] Q1, C5, C6 External Oscillator Block [0217] [26] 28C, R6, R7 voltage divider block to ADC block sensor [0218] [27] T2, R8 Firing Regulator Block [0219] [28] IC1 Microcontroller Block [0220] [28A] Clock Source [0221] [28B] I/O input and output ports [0222] [28C] Sensor Input (ADC Analog to Digital) [0223] [28D] Interruption when entering data through the port [0224] [28E] TX transmission serial data output (UART) [0225] [28F] CPU Function and data storage processor [0226] [29] C7, T3, R10, R5 Capacitor load activation block [0227] [30] Filament (FIG. 3) [12] [0228] [31] IC1 Microcontroller Programming Socket [0229] [32] IC1 Microcontroller Programming Flash Memory [0230] [33] CPU with its internal peripherals attached [0231] [34] External Oscillator and time generator connection block to the CPU [0232] [35] CPU-connected peripheral bus [0233] [36] Clock source of IC1 microcontroller, OSC (External Oscillator) [0234] [37] Pulse source for TIMER1 counter from OSC Q1. [0235] [38] Output I/O port for charging Capacitor C7 (28B FIG. 4) [0236] [39] Output I/O Port for discharging Capacitor C7 (28B FIG. 4) [0237] [40] Output I/O Port for firing, discharge of Capacitor C7 on Filament [30] (28B FIG. 4) [0238] [41] Input I/O port via interrupt (INT), for data processing (28D FIG. 4) [0239] [42] Input to the ADC module, for the voltage sensor. (28C FIG. 4) [0240] [43] Serial transmission output PIN TX (UART) (28E FIG. 4)

[0241] FIG. 1:

[0242] This figure shows two diagrams, A and B, where the left diagram or FIG. 1A shows the arrangement of the elements of the present system using a single parallel Communication and Power line [02A and 02B] for a single Programmable Non-Explosive Electronic Initiator [07] and an RFID reader that reads the unique identifier code ID of the Programmable Non-Explosive Electronic Initiator [07]. Diagram B, or FIG. 1B, shows the present system using a single parallel Communication and Power line [02A and 02B] for four or more Programmable Non-Explosive Electronic Initiators [07].

[0243] FIG. 2:

[0244] This figure shows three diagrams A, B and C, representing voltage waves, where FIG. 2A, above, shows the beginning of the bidirectional communication, where the Voltage Modulation [03] sent consists of a constant square wave with a defined amplitude between 24V and 35V and a period of 4.0 ms. The high bit of 4 milliseconds and the low bit of 0.2 milliseconds allow for a constant voltage to be maintained.

[0245] FIGS. 2B and 2C present diagrams showing the details of a bidirectional communication protocol with a transmission rate of 2,400 bits per second that is used in the Communication and Power Line [02A and 02B].

[0246] FIG. 3:

[0247] This figure shows three diagrams: A, B and C, where the first two show a schematic description of the Printed Circuit Board (PCB). Diagram C shows a detail of the interaction between Filament [12] coated with a Rapidly Expanding Metal Mixture [13], inserted in a Shrink Sleeve [14], where the Shrink Sleeve [14] holds together the Filament [12] with the Rapidly Expanding Metal Mixture [13], and where the Shrink Sleeve [14] is contained by a Capsule container [16] which in turn contains another amount of a Rapidly Expanding Metal Mixture [15].

[0248] FIG. 4:

[0249] This figure shows a schematic circuit of the Programmable Non-Explosive Electronic Initiator [07].

[0250] FIG. 5:

[0251] This figure shows a specification of the CPU programming and feedback [28F] described in the schematic circuit of the Programmable Non-Explosive Electronic Initiator [07].

[0252] FIG. 6:

[0253] This figure is a detailed representation of the dynamics generated in the Clock Source Block [28A].

[0254] FIG. 7:

[0255] This figure shows a diagram of how the square wave with the data is transmitted from the Command Unit [01] to the INT/IO PORT input pin [41] and 10 output ports [28B](for charging Capacitor C7 [38], for discharging Capacitor C7 [39], for firing and discharging Capacitor C7 in Filament [30] [40]) (FIG. 4) of the IC1 Microprocessor [28], converting it into bytes with the use of an algorithm. On the other hand, FIG. 7 refers to PINs C0, C3, C5 of the IC1 microcontroller in FIG. 4.

[0256] FIG. 8:

[0257] This figure shows a diagram of the analog information received by the Microprocessor IC1 [28] through the ADC/AN pin [42] (FIG. 4) [28C] where it is converted to digital for sensor readout.

[0258] FIG. 9:

[0259] This figure shows a diagram of how Microprocessor IC1 [28], through the USART transmission block pin TX [43] (FIG. 4) [28E], transmits the output data, where the output data is inserted through a transistor T1 and two resistors R3 and R4 [23] in the Communication and Power Line [02A and 02B].

Example of Application

[0260] In order to calculate the ignition temperature of the primary metallic mixture, the following mixture Al+Fe2O3+NaNO3(Aluminum+Iron Oxide+Sodium Nitrate) was used, using the following equations:

[0261] The resistivity of a metal (p) increases with temperature; this relationship is determined by the following equation:

(T)=.sub.o (1+(T))(Equation No. 1)

[0262] Where: [0263] (T)=Resistivity of a metal as a function of a temperature differential. [0264] .sub.o=Initial metal resistivity. [0265] =Temperature coefficient per centigrade degree of the metal. [0266] T=Temperature differential (T.sub.FinalT.sub.initial).

[0267] In turn, the resistivity of a metal is directly proportional to the resistance of the metal, the relationship between the two is given by:

R=*L/A(Equation No. 2)

[0268] Where: [0269] R=Metal resistance [0270] =Metal resistivity [0271] L=Length of metal wire [0272] A=Wire surface

[0273] Knowing the values at an ambient temperature of To=20 C. and Ro at that temperature equal to 10.5, the temperature coefficient (a) of tungsten is =0.0045. If we do an experimental calculation of the RF resistance of tungsten, we get, when applying a voltage of V=24 V (volts), 20V calculated by the voltage drop and an electric current I=0.100 A (amperes) and substituting the resistivity () of equation No. 2 in equation No. 1.

=R*A/L(Equation No. 2)

(R*A(T))/L=(R.sub.0*A(1+(T.sub.FT.sub.o)))/L(Equation No. 1)

[0274] Multiplying both members by L/A

(R*A(T)*L)*(L/A)=(R.sub.o*A(1+(T.sub.FT.sub.o)))*(L/A)

R(T)=R.sub.o(1+(T.sub.FT.sub.o))(Equation No. 3)

Where:

[0275] R(T)=Resistance of the metal to a temperature variation. [0276] R.sub.o=Metal resistance at T.sub.o [0277] =Temperature coefficient per centigrade degree of the metal. [0278] T.sub.F=Temperature variation with respect to the initial temperature [0279] T.sub.o=Initial metal temperature

[0280] Determining variable T.sub.F from equation No. 3:

T.sub.F=((R.sub.F/Ro)1)/+T.sub.o(Equation No. 4)

[0281] Calculating experimentally with the discharge of capacitor C7 gives us a final resistance per temperature difference of 90 ohm, substituting these values in equation No. 4:

T.sub.F=((90/10.5)1)/0.0045+20 C. [0282] T.sub.F=1,702 C.

[0283] Based on the results obtained, it is concluded that at an ambient temperature of 20 C., the filament temperature for igniting the first rapidly expanding metallic mixture [13] is approximately 1,702 C.

[0284] Considering that the melting point of tungsten metal is 3,422 C., it is concluded that the filament will not break before activating the first rapidly expanding metallic mixture [13].

[0285] Since the filament incandescence has a time limit [30], in an environment exposed to oxygen (no vacuum) its consumption is inevitable. Once the discharge of capacitor C7 [31a] is activated, the minimum average glow period of filament [30] is greater than 100 milliseconds, enough time for the glow of filament [30] to activate the first rapidly expanding metallic mixture [13].