A circuit for accurately judging the resistance of the bridge wire of an electronic detonator

Abstract

The utility model discloses a circuit for accurately judging the resistance of the bridge wire of an electronic detonator, comprising a bridge wire and an energy storage capacitor externally placed on an electronic detonator chip, wherein the bridge wire is electrically connected to the energy storage capacitor; and an operational amplifier, a voltage comparator, a digital-to-analog converter, a PMOS tube and an NMOS tube built into the electronic detonator chip, wherein the operational amplifier is electrically connected to the voltage comparator, the voltage comparator is electrically connected to the digital-to-analog converter, the PMOS tube is electrically connected to the energy storage capacitor, and the NMOS tube is electrically connected to the bridge wire. The utility model can screen and measure the resistance of the bridge wire of the electronic control module of the finished electronic detonator, select products with higher consistency, and greatly help to improve the accuracy rate of explosion and the safety of blasting.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic detonator detection, in particular to a circuit for accurately judging the resistance of a bridge wire of an electronic detonator. Background Art

[0002] The electronic control module is the core control device of the electronic detonator. The electronic control module is built into the electronic detonator. Its chip component has the detonator identity information, has the detonator detonation control function or detonation delay time control, can test the on-off state of the ignition element, and is a dedicated circuit module that can communicate with the detonation controller and other external control devices. The ignition control principle is: open the switch through the command, convert the energy stored in the ignition capacitor in the module into heat through the transducer element, thereby igniting the charge head to achieve ignition.

[0003] The transducer element refers to the first element of the pyrotechnics that converts the control energy into ignition energy and stimulates the ignition agent to ignite. At present, although there are many types of transducer elements, they usually use a metal bridge wire as an energy conversion device. As an energy storage device, the ignition capacitor has limited energy storage voltage and capacity due to its specifications and models. At the moment of discharge, the current flows through the bridge wire of the transducer element through the discharge circuit to generate heat. According to Ohm's law and the law of conservation of energy, we know that the amount of heat generated by the bridge wire is related to the resistance of the bridge wire. Therefore, the detection of the bridge wire resistance and the guarantee of the accuracy of the bridge wire resistance and the consistency of the bridge wire resistance of the same batch of products are one of the important indicators for the reliable ignition of electronic detonators.

[0004] At present, during the production of the module, the bridge wire resistance can be accurately measured through external devices. However, when the detonator is generated, the bridge wire has been coated with ignition agent. Especially after the electronic detonator is installed, the bridge wire resistance cannot be directly detected and verified by external equipment. Only through the electronic control module’s own circuit, the external detection equipment can judge the state of the bridge wire through instructions and status. In actual use, the production of electronic detonators will also go through transportation and storage, which may cause abnormal bridge wires. When using, the detonators with abnormal bridge wires must be removed through external equipment to ensure blasting safety and blasting effect. At present, the electronic control modules on the market can only judge the on and off of the bridge wire through instructions, that is, they can only judge the situation where the bridge wire resistance is 0Ω, or KΩ, MΩ. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a circuit for accurately judging the resistance of the bridge wire of an electronic detonator, so as to solve the problem raised in the background technology.

[0006] In order to solve the above technical problems, the technical solution of the utility model is: a circuit for accurately judging the resistance of the bridge wire of an electronic detonator, comprising a bridge wire and an energy storage capacitor externally disposed on an electronic detonator chip, wherein the bridge wire is electrically connected to the energy storage capacitor; and an operational amplifier, a voltage comparator, a digital-to-analog converter, a PMOS tube and an NMOS tube built into the electronic detonator chip, wherein the operational amplifier is electrically connected to the voltage comparator, the voltage comparator is electrically connected to the digital-to-analog converter, the PMOS tube is electrically connected to the energy storage capacitor, and the NMOS tube is electrically connected to the bridge wire.

[0007] Preferably, the PMOS tube is connected to a first resistor to form a current limiting circuit.

[0008] Preferably, a second resistor is connected in series between the current limiting circuit and the bridge wire.

[0009] Preferably, a third resistor is connected in series between the energy storage capacitor and the operational amplifier.

[0010] Preferably, a fourth resistor and a fifth resistor are connected to the operational amplifier, and the fifth resistor is connected to the operational amplifier in parallel.

[0011] Preferably, a sixth resistor is connected in series between the operational amplifier and the voltage comparator.

[0012] Preferably, the resistance value of the bridge wire is 1-10Ω.

[0013] Preferably, the precision of the digital-to-analog converter is 8 bits, and its value is 0-255.

[0014] Preferably, the internal resistance of the PMOS tube is less than 1Ω; and the internal resistance of the NMOS tube is less than 0.2Ω.

[0015] Compared with the prior art, the beneficial effects of the utility model are:

[0016] When measuring the resistance of the bridge wire, the utility model uses a specific bridge wire detection instruction to make QS_ON_P output a low level, the PMOS tube is turned on, and at the same time, QS_ON_N outputs a high level, the NMOS tube is turned on, and the PMOS tube and the first resistor form a current limiting circuit, so that the current flowing through the PMOS tube is limited to 1mA. This current flows through the second resistor, the bridge wire and the NMOS tube. Since the internal resistance of the NMOS tube is very small, the voltage at both ends of the bridge wire is very low, not exceeding 10mV, and the influence of the energy storage capacitor can be ignored. The voltage of the bridge wire is amplified by the operational amplifier, the fourth resistor, and the 100-fold in-phase amplifier composed of the fourth resistor, and then compared by a voltage comparator. The reference voltage of the voltage comparator is given by the instruction received by the chip after conversion by the digital-to-analog converter, and its output range is 0.1-1.1V. The output (0 or 1) of the voltage comparator is directly connected to the digital part of the chip and read by the digital part. The utility model can screen and measure the resistance of the bridge wire of the electronic control module of the finished electronic detonator, select products with higher consistency, and is of great help to improve the accuracy rate and blasting safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the utility model. DETAILED DESCRIPTION

[0018] The specific implementation methods of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these implementation methods is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in each implementation method of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0019] Reference Figure 1 The utility model discloses a circuit for accurately judging the resistance of the bridge wire of an electronic detonator, comprising a bridge wire 1 and an energy storage capacitor 2 externally disposed on an electronic detonator chip, wherein the bridge wire 1 is electrically connected to the energy storage capacitor 2; and an operational amplifier 3, a voltage comparator 4, a digital-to-analog converter 5, a PMOS tube 6 and an NMOS tube 7 built into the electronic detonator chip, wherein the operational amplifier 3 is electrically connected to the voltage comparator 4, the voltage comparator 4 is electrically connected to the digital-to-analog converter 5, the PMOS tube 6 is electrically connected to the energy storage capacitor 2, and the NMOS tube 7 is electrically connected to the bridge wire 1.

[0020] In the present invention, the PMOS tube 6 is connected to the first resistor 8 to form a current limiting circuit 608 .

[0021] In the present invention, a second resistor 9 is connected in series between the current limiting circuit 608 and the bridge wire 1 .

[0022] In the present invention, a third resistor 10 is connected in series between the energy storage capacitor 2 and the operational amplifier 3 .

[0023] In the present invention, a fourth resistor 11 and a fifth resistor 12 are connected to the operational amplifier 3 , and the fifth resistor 12 is connected to the operational amplifier 3 in parallel.

[0024] In the present invention, a sixth resistor 13 is connected in series between the operational amplifier 3 and the voltage comparator 4 .

[0025] In the present invention, the resistance value of the bridge wire 1 is 1-10Ω.

[0026] In the present invention, the accuracy of the digital-to-analog converter 5 is 8 bits, and its value is 0-255.

[0027] In the present invention, the internal resistance of the PMOS tube 6 is less than 1Ω; the internal resistance of the NMOS tube 7 is less than 0.2Ω.

[0028] In the utility model, QS is the bridge wire 1 of the electronic detonator, with a resistance value of 1-10Ω, C1 is the energy storage capacitor 2 of the electronic detonator, U1B is the operational amplifier 3, U2B is the voltage comparator 4, DAC is the digital-to-analog converter 5, Q1 is the PMOS tube 6, and Q2 is the NMOS tube 7.

[0029] The working principle is: when measuring the resistance of the bridge wire 1, through a specific bridge wire 1 detection instruction, QS_ON_P outputs a low level, the PMOS tube is turned on, and at the same time QS_ON_N outputs a high level, the NMOS tube 7 is turned on, and the PMOS tube 6 and the first resistor 8 form a current limiting circuit 608, so that the current flowing through the PMOS tube 6 is limited to 1mA. This current flows through the second resistor 9, the bridge wire 1 and the NMOS tube 7. Since the internal resistance of the NMOS tube 7 is very small, the voltage across the bridge wire 1 is very low, not exceeding 10mV, and the influence of the energy storage capacitor 2 can be ignored. The voltage of the bridge wire 1 is amplified by the operational amplifier 3, the fourth resistor 11, and the 100-fold in-phase amplifier composed of the fourth resistor 11, and then compared by the voltage comparator 4. The reference voltage of the voltage comparator 4 is given by the instruction received by the chip and converted by the digital-to-analog converter 5. Its output range is 0.1-1.1V. The output (0 or 1) of the voltage comparator 4 is directly connected to the digital part of the chip and read by the digital part.

[0030] Example

[0031] At present, the bridge wire resistance commonly used in electronic detonators is between 2Ω-15Ω, the capacity of the ignition capacitor is between 33uF-110uF, and the maximum withstand voltage of the ignition capacitor is between 10V-25V.

[0032] We take the bridge wire resistance of 4.8Ω, the allowable effective deviation of ±0.2Ω, and the ignition capacitor of 68uF / 20V as an example.

[0033] First, we set the DAC to 255, read U2B, and observe whether it is 0. If it is 0, the bridge wire resistance is less than 11Ω, and continue to measure; if it is 1, it proves that the bridge wire is broken;

[0034] Since we know the resistance range of the bridge wire, there is no need to reduce the DAC value for testing. We directly set the DAC value to 103 (corresponding to the bridge wire resistance of 5.04Ω), read U2B, and observe whether it is 0. If it is 0, the bridge wire resistance is less than 5.04Ω, and continue to measure; if it is 1, it proves that the bridge wire resistance is greater than 5.04 ohms, which is beyond the permitted range and is eliminated;

[0035] Set the DAC value to 102 (corresponding to the bridge wire resistance of 5.00Ω), read U2B, and observe whether it is 0. If it is 0, the bridge wire resistance is less than 5.00Ω, and continue to measure; if it is 1, it proves that the bridge wire resistance is equal to 5.00 ohms, which meets the requirements;

[0036] Set the DAC value to 92 (corresponding to the bridge wire resistance of 4.60Ω), read U2B, and observe whether it is 0. If it is 0, the bridge wire resistance is less than 4.6Ω, which is beyond the allowable range and is discarded.

[0037] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the scope of protection of the present invention.

Claims

1. A circuit for accurately determining the resistance of an electronic detonator bridge wire, characterized in that: The invention comprises a bridge wire (1) and an energy storage capacitor (2) externally arranged on an electronic detonator chip, wherein the bridge wire (1) is electrically connected to the energy storage capacitor (2); and an operational amplifier (3), a voltage comparator (4), a digital-to-analog converter (5), a PMOS tube (6) and an NMOS tube (7) built into the electronic detonator chip, wherein the operational amplifier (3) is electrically connected to the voltage comparator (4), the voltage comparator (4) is electrically connected to the digital-to-analog converter (5), the PMOS tube (6) is electrically connected to the energy storage capacitor (2), and the NMOS tube (7) is electrically connected to the bridge wire (1).

2. The circuit for accurately determining the resistance of the electronic detonator bridge wire according to claim 1 is characterized in that: The PMOS tube (6) is connected to the first resistor (8) to form a current limiting circuit (608).

3. The circuit for accurately determining the resistance of the electronic detonator bridge wire according to claim 2 is characterized in that: A second resistor (9) is connected in series between the current limiting circuit (608) and the bridge wire (1).

4. The circuit for accurately determining the resistance of the bridge wire of an electronic detonator according to claim 1 is characterized in that: A third resistor (10) is connected in series between the energy storage capacitor (2) and the operational amplifier (3).

5. The circuit for accurately determining the resistance of the electronic detonator bridge wire according to claim 1 is characterized in that: The operational amplifier (3) is connected to a fourth resistor (11) and a fifth resistor (12), and the fifth resistor (12) is connected in parallel to the operational amplifier (3).

6. The circuit for accurately determining the resistance of the electronic detonator bridge wire according to claim 1, characterized in that: A sixth resistor (13) is connected in series between the operational amplifier (3) and the voltage comparator (4).

7. The circuit for accurately determining the resistance of the electronic detonator bridge wire according to claim 1 is characterized in that: The resistance value of the bridge wire (1) is 1-10Ω.

8. The circuit for accurately determining the resistance of the bridge wire of an electronic detonator according to claim 1 is characterized in that: The accuracy of the digital-to-analog converter (5) is 8 bits, and its value is 0-255.

9. The circuit for accurately determining the resistance of the bridge wire of an electronic detonator according to claim 1, characterized in that: The internal resistance of the PMOS tube (6) is less than 1Ω; the internal resistance of the NMOS tube (7) is less than 0.2Ω.

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