Electronic detonator chip suitable for measuring resistance value of ignition element and measuring method

Abstract

The invention provides an electronic detonator chip suitable for ignition element resistance measurement and a measurement method. The electronic detonator chip comprises a constant current source, an amplifier, an analog-to-digital converter ADC, a voltage comparator, an energy storage capacitor charging and discharging control circuit, an NMOS ignition switch and an NMOS control circuit. And the electronic detonator chip is electrically connected with an external ignition element and an energy storage capacitor. According to the invention, the high-gain amplifier is adopted, and the standard resistor is used for calibration during packaging test to offset the defect of large error of the high-gain amplifier, so that the problem of insufficient resolution of the low-precision analog-to-digital converter ADC is solved, the 8-bit analog-to-digital converter ADC can be adopted as a chip, and the required chip area is greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic detonators, and in particular to an electronic detonator chip suitable for measuring the resistance of an ignition element and a measurement method. Background Art

[0002] Before use in the field, electronic detonators must undergo a self-test of all functions. Self-testing the resistance of the ignition element is particularly important. If the ignition resistor breaks or increases in resistance due to oxidation, the charge head will not ignite properly, resulting in unexploded detonators and explosives remaining at the blasting site. This can easily damage equipment and even cause casualties during subsequent removal. Therefore, it is essential to test the resistance of the detonator's ignition element and eliminate any abnormally resistant detonators in advance.

[0003] Chinese patent publication CN114993121A discloses a system and method for measuring the firing resistance of electronic detonators. The system includes an electronic detonator chip and a host computer. The electronic detonator chip processes the firing resistance to obtain an analog-to-digital conversion result. The host computer processes the analog-to-digital conversion result to obtain the value of the firing resistance. This solution actually measures the sum of the firing resistance and the on-resistance of NMOS1 and NMOS2 (NMOS1 and NMOS2 are ordinary switching tubes rather than high-power firing switches. Their on-resistance is of the same order of magnitude as the firing element resistance and cannot be ignored). However, due to the influence of the contact resistance between the chip and the test equipment during packaging testing, the on-resistance of NMOS1 and NMOS2 cannot be accurately measured, which makes this solution unable to achieve accurate resistance measurement.

[0004] Chinese patent publication CN111207634B discloses a digital electronic detonator chip with resistance detection functionality and its resistance detection method. The chip features a test switch connected in parallel to the detonator chip's initiation switch. In the test state, turning on the test switch causes a short, low current to flow through the bridge wire. Furthermore, a high-precision 16-bit analog-to-digital converter (ADC) is used to achieve a resolution of 0.1 ohm for detecting the bridge wire resistance. The voltage across the bridge wire is measured separately and, combined with the known current value, the bridge wire resistance is calculated. Multiple measurements can be performed, and the average value calculated to increase accuracy. The detection results are transmitted to a bus via a communication module for recording and calculation. However, this solution relies on a 12-bit ADC, which is practically unfeasible due to chip area limitations. Furthermore, this solution requires measuring the voltage across the bridge wire. Measuring the negative end of the bridge wire inevitably introduces damage to the chip's measurement circuitry, leading to the risk of premature detonation even when no measurement is performed.

[0005] In the Chinese patent document with publication number CN113075455A, a method and device for detecting the resistance of an electronic detonator bridge wire, an electronic detonator, and a system are disclosed. The method includes: obtaining a detection instruction; charging the energy storage capacitor according to the detection instruction so that the voltage value of the energy storage capacitor rises to a target initial voltage value; controlling the discharge module to discharge the energy storage capacitor so that the voltage value of the energy storage capacitor drops to a target final voltage value, and recording the discharge time used for the voltage value of the energy storage capacitor to drop to the target final voltage value; the discharge module includes a bridge wire resistor and a discharge resistor; calculating the resistance value of the bridge wire resistor based on the resistance value, discharge time, target initial voltage value, and target final voltage value of the discharge resistor; sending the resistance value of the bridge wire resistor to a detection device so that the detection device generates a detection result based on the resistance value of the bridge wire resistor. This solution is to discharge through the bridge wire and record the time used in the discharge process to convert the resistance value. This method actually measures the average current of the discharge process, but when ensuring that the current passing through the bridge wire does not exceed the safety limit (generally defined as 1mA), the factors affecting the current are obviously not only the resistance of the bridge wire itself, but also the influence of the discharge circuit in the chip is greater. Therefore, this solution cannot actually measure the precise resistance value of the resistor, but can only be used to determine whether the resistance value has changed significantly. Summary of the Invention

[0006] In view of the defects in the prior art, the purpose of the present invention is to provide an electronic detonator chip and a measurement method suitable for measuring the resistance of an ignition element.

[0007] According to the present invention, an electronic detonator chip suitable for measuring the resistance of an ignition element comprises: a constant current source, an amplifier, an analog-to-digital converter (ADC), a voltage comparator, a charge and discharge control circuit for an energy storage capacitor, an NMOS ignition switch, and an NMOS control circuit; the electronic detonator chip is electrically connected to an external ignition element and an energy storage capacitor;

[0008] The output end of the constant current source is electrically connected to the positive electrode of the ignition element;

[0009] The positive input of the amplifier is electrically connected to the positive electrode of the ignition element, the negative input of the amplifier is electrically connected to the chip ground, and the output of the amplifier is electrically connected to the analog-to-digital converter ADC;

[0010] The positive input of the voltage comparator is connected to the signal after the voltage is divided by the VCHG pin of the chip, and the negative input of the voltage comparator is connected to the reference voltage signal;

[0011] One end of the energy storage capacitor charge and discharge control circuit is electrically connected to the chip VCHG pin, and the other end of the energy storage capacitor charge and discharge control circuit is electrically connected to the chip ground;

[0012] The positive electrode of the ignition element and one end of the energy storage capacitor are electrically connected to the VCHG pin of the chip, the other end of the energy storage capacitor is electrically connected to the chip ground, the negative electrode of the ignition element is connected to the drain of the NMOS ignition switch, the source of the NMOS ignition switch is electrically connected to the chip ground, and the NMOS control circuit is electrically connected to the gate of the NMOS ignition switch.

[0013] Preferably, the gain range of the amplifier is set according to the acquisition range of the analog-to-digital converter ADC, and the output signal of the amplifier is placed in the middle of the input range of the analog-to-digital converter ADC.

[0014] Preferably, a zero adjustment switch is provided in the amplifier, and the zero adjustment switch is used to short-circuit the positive input and negative input of the amplifier.

[0015] Preferably, the positive input of the voltage comparator is connected to the VCHG pin of the chip through a voltage divider circuit, and the voltage divider circuit includes a resistor R1 and a resistor R2, one end of the resistor R2 is connected to the VCHG pin of the chip, the other end of the resistor R2 is electrically connected to one end of the resistor R1 and the positive input of the voltage comparator, and the other end of the resistor R1 is electrically connected to the chip ground;

[0016] The resistance relationship between the resistor R1 and the resistor R2 is:

[0017] R2=9R1.

[0018] Preferably, it also includes a PMOS ignition switch and a PMOS control circuit;

[0019] The PMOS control circuit is electrically connected to the gate of the PMOS ignition switch, the source of the PMOS ignition switch is electrically connected to the chip VCHG pin, the positive electrode of the ignition element is electrically connected to the drain of the PMOS ignition switch, and the ignition element is connected or disconnected to the chip VCHG pin through the PMOS ignition switch.

[0020] Preferably, the NMOS ignition switch is arranged on the periphery of the electronic detonator chip, and the NMOS ignition switch is electrically connected to a pin arranged on the electronic detonator chip.

[0021] A method for measuring the resistance of an ignition element according to the present invention includes:

[0022] Step S1: turning on the energy storage capacitor charge and discharge control circuit to discharge the energy storage capacitor;

[0023] Step S2: disconnecting the energy storage capacitor charge and discharge control circuit, and determining whether the residual voltage of the energy storage capacitor is less than a safety value through a voltage comparator. If so, proceed to step S3; if not, terminate the measurement.

[0024] Step S3: starting the constant current source to output current to the positive electrode of the ignition element; turning on the NMOS ignition switch through the NMOS control circuit;

[0025] Step S4: closing the zeroing switch in the amplifier, starting the analog-to-digital converter ADC, performing multiple samplings, and recording the average value;

[0026] Step S5: disconnecting the zeroing switch in the amplifier, restarting the analog-to-digital converter ADC, performing multiple samplings, and recording the average value;

[0027] Step S6: turning off the constant current source, disconnecting the NMOS firing switch through the NMOS control circuit, and turning on the energy storage capacitor charge and discharge control circuit to discharge the energy storage capacitor;

[0028] Step S7: Subtract the two average values to obtain the measured resistance of the ignition element, and calculate the real resistance R of the ignition element according to the preset conversion coefficient.

[0029] Preferably, in step S3 to step S5, the voltage comparator is always used to determine whether the residual voltage of the energy storage capacitor is less than the safety value. If so, the measurement continues; if not, the measurement ends.

[0030] Preferably, a calibration step is further included, wherein the calibration step comprises: replacing the ignition element with two standard resistors of known resistance values, and executing steps S1 to S7 to obtain measured values of the standard resistors and calculate a conversion factor k;

[0031] k=(Rs2-Rs1)÷(s2-s1)

[0032] Wherein, Rs1 represents the standard resistance value of the first standard resistor, and s1 represents the measured resistance value of the first standard resistor; Rs2 represents the standard resistance value of the second standard resistor, and s2 represents the measured resistance value of the second standard resistor;

[0033] Updated the conversion factors in the electronic detonator chip.

[0034] Preferably, the calculation formula for the real resistance R of the ignition element is:

[0035] R=k×S-Rdson

[0036] Where S is the measured resistance of the ignition element, and Rdson is the nominal value of the on-resistance of the NMOS ignition switch.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. The present invention solves the problem of insufficient resolution of low-precision analog-to-digital converters (ADCs) by adopting high-gain amplifiers, allowing the chip to adopt an 8-bit analog-to-digital converter (ADC), significantly reducing the required chip area.

[0039] 2. The present invention uses standard resistors for calibration during packaging testing to offset the disadvantage of large errors in high-gain amplifiers. By adopting a method of using standard resistors of two resistance values for calibration during packaging testing, the disadvantage of large errors in high-gain amplifiers is solved, making it possible to use high-gain operational amplifiers.

[0040] 3. The present invention eliminates the inherent deviation inside the high-gain amplifier by adopting a structure in which a zero adjustment circuit is set inside the amplifier and a method of performing zero adjustment during each measurement. As a result, the only inherent deviation in the packaging test calibration process is the contact resistance, which solves the problem of difficulty in eliminating the contact resistance randomly generated during the calibration process and makes calibration possible during packaging testing.

[0041] 4. The present invention adopts the method of turning on the NMOS ignition switch for measurement, which eliminates the need to set a pin for connecting the chip to the negative end of the ignition element, thereby eliminating the risk of premature explosion caused by breakdown of the chip measurement circuit.

[0042] 5. The present invention adopts a double insurance scheme of discharging before measurement and detecting the voltage of the energy storage capacitor during the entire measurement process to ensure that no danger occurs when performing the measurement.

[0043] 6. The minimum resolution of the resistance value measured by the chip disclosed in the present invention is reduced to about 50mΩ, making it possible to measure the resistance value of the ignition element without relying on external equipment during the production and use of the electronic detonator module and the electronic detonator. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0045] Figure 1 This is a principle block diagram of Example 1 of the electronic detonator chip of the present invention;

[0046] Figure 2 This is a principle block diagram of Example 2 of the electronic detonator chip of the present invention;

[0047] Figure 3 This is a flow chart of a method for measuring the resistance of an ignition element in the present invention;

[0048] Figure 4 This is a flow chart of the ignition element resistance measurement and calibration method in the present invention. DETAILED DESCRIPTION

[0049] The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0050] The present invention discloses an electronic detonator chip suitable for measuring the resistance of ignition components. The internal principle block diagram and related peripheral circuits are shown in the attached figure. Figure 1 and attached Figure 2 As shown, the chip structure is as follows:

[0051] The chip integrates a constant current source, whose output is connected to the chip's YTP pin. The output current range varies depending on the resistance range of the ignition element being tested and should also take into account relevant safety standards. It is generally between 200μA and 1mA. In a preferred embodiment of the present invention, the output current is 850μA.

[0052] The chip integrates a high-gain amplifier. Its positive input is connected to the chip's YTP pin via a high-resistance resistor, while its negative input is connected to chip ground via a similarly high-resistance resistor. Its gain varies depending on the resistance range of the ignition element being tested, generally ranging from 25 to 200 times. The amplifier's function is to place the input signal of the analog-to-digital converter (ADC) in the middle of its input range. In a preferred embodiment of the present invention, its gain is 100 times. The amplifier includes a switch, called a zeroing switch, that short-circuits its positive and negative inputs. An 8-bit analog-to-digital converter (ADC) is integrated into the chip, and its input is connected to the output of the high-gain amplifier.

[0053] The chip integrates a voltage comparator, whose positive input is connected to the chip's VCHG pin, a signal divided by a resistor by 1 / 10, and whose negative input is connected to the chip's 0.1V reference voltage signal. In one specific embodiment, the positive input of the voltage comparator is connected to the chip's VCHG pin via a voltage divider circuit. The voltage divider circuit includes resistors R1 and R2. One end of resistor R2 is connected to the chip's VCHG pin, and the other end of resistor R2 is electrically connected to one end of resistor R1 and the positive input of the voltage comparator. The other end of resistor R1 is electrically connected to the chip ground.

[0054] The resistance relationship between the resistor R1 and the resistor R2 is:

[0055] R2=9R1.

[0056] The chip also integrates a storage capacitor charge and discharge control circuit, which can charge or discharge the storage capacitor through the VCHG pin. The discharge method is to short the VCHG pin to ground.

[0057] The chip also integrates an NMOS ignition switch and an NMOS control circuit. The output of the NMOS control circuit is connected to the gate of the NMOS ignition switch. The drain of the NMOS ignition switch is connected to the negative terminal of the ignition element, and the source of the NMOS ignition switch is grounded. In a preferred embodiment, the NMOS ignition switch can be integrated within the chip or arranged as a discrete device on the chip's periphery. In Example 1 of the present invention, the NMOS ignition switch is integrated within the chip. In Example 2 of the present invention, the NMOS ignition switch is arranged on the chip's periphery.

[0058] Energy storage capacitors and ignition elements are located around the chip. The positive end of the energy storage capacitor is connected to the chip's VCHG pin and the positive end of the ignition element, while the negative end is grounded. The positive end of the ignition element is connected to the chip's YTP pin and the positive end of the energy storage capacitor, while the negative end is connected to the drain of the NMOS ignition switch.

[0059] A PMOS ignition switch can also be provided on the periphery of the chip, and a corresponding PMOS control circuit is provided in the electronic detonator chip. In this case, the positive end of the energy storage capacitor is no longer directly connected to the positive end of the ignition element, but is connected to the source of the PMOS ignition switch. The positive end of the ignition element is connected to the drain of the PMOS ignition switch, and the output of the PMOS control circuit is connected to the gate of the PMOS ignition switch. When the PMOS ignition switch is provided, the output of the PMOS control circuit is connected to the gate of the PMOS ignition switch. When the PMOS ignition switch is not provided, the output of the PMOS control circuit is left floating. Providing a PMOS ignition switch can further enhance the safety of the present invention, but will increase production costs, and is therefore an optional option. There is no PMOS ignition switch in Example 1 of the present invention, but there is a PMOS ignition switch in Example 2 of the present invention.

[0060] The present invention also discloses a method for measuring the resistance of an ignition element, which uses the above-mentioned electronic detonator chip and is divided into two groups of processes, namely a measurement process for each measurement and a process for accurately measuring the resistance of the ignition element using the above-mentioned measurement process.

[0061] The specific measurement method process is as follows Figure 3 As shown, the steps include:

[0062] Step S1: Discharging step: Turn on the discharge switch in the charge and discharge control circuit to discharge the energy storage capacitor through the VCHG pin.

[0063] Step S2: Safety check step. Disconnect the discharge switch in the charge and discharge control circuit. Use a comparator to check whether the divided voltage on the VCHG pin is greater than 0.1V, that is, whether the VCHG pin voltage is greater than 1V. If it is not greater than 1V, proceed to step S3; otherwise, exit and end the measurement.

[0064] Step S3: Establishing the measurement state. The constant current source is activated to output current to the YTP pin. The NMOS ignition switch control circuit is used to turn on the NMOS ignition switch. In this step, the comparator is used to check whether the VCHG pin voltage is greater than 1V. If it is not, the process continues; otherwise, the process exits.

[0065] Step S4: Zeroing. Close the zeroing switch in the amplifier, then start the analog-to-digital converter (ADC), perform Nz consecutive sampling, and record the average value. During this step, the comparator continues to check whether the voltage on the VCHG pin is greater than 1V. If not, the process continues; otherwise, the process exits. The value of Nz is a trade-off between measurement time and accuracy, typically between 2 and 8. In one embodiment of the present invention, Nz = 4.

[0066] Step S5: Actual sampling step. The zeroing switch in the amplifier is disconnected, and the analog-to-digital converter (ADC) is activated. Nm samples are continuously taken, and the average value is recorded. During this step, the comparator is still used to check whether the voltage on the VCHG pin is greater than 1V. If not, the process continues; otherwise, the process exits. The value of Nm is a compromise between measurement time and accuracy, and is generally between 2 and 8. In one embodiment of the present invention, Nm = 4.

[0067] Step S6: End step. Turn off the constant current source; use the NMOS firing switch control circuit to turn off the NMOS firing switch; turn on the discharge switch in the charge and discharge control circuit to discharge the energy storage capacitor through the VCHG pin.

[0068] Step S7: Feedback step: The electronic detonator chip feeds back the average value of the two samples obtained in the zeroing step and the actual sampling step to the host computer, and the host computer subtracts the two average values of the samples to obtain the final measurement value of this measurement.

[0069] The process of using the above measurement process to accurately measure the resistance of the ignition element is as follows: Figure 4 As shown, this process is to calibrate the chip by executing the first set of measurement method processes twice when the chip leaves the factory, and then execute the first set of measurement method processes again when the chip is actually used to convert the actual resistance value. The steps include:

[0070] Step A1: Package Test Step. During the electronic detonator chip package test, replace the ignition element with a standard resistor of known resistance and perform two measurements. This calculation will determine the conversion factor between the measured chip value and the measured resistor value. Care should be taken to only replace the resistor between measurements; do not change the connection between the chip and the test equipment. Ensure that the contact resistance between the chip and the test equipment remains consistent between measurements to eliminate any influence from contact resistance.

[0071] Step A1.1: Calibrate a small-value standard resistor. Replace the ignition element with a small-value standard resistor. Record the resistance of this resistor as Rs1. Perform a measurement according to the above measurement process to obtain the measured value s1. The value of Rs1 should be less than the resistance of the smallest ignition element that can be used in this model of electronic detonator.

[0072] Step A1.2: Calibrate a high-value standard resistor. Replace the ignition element with a high-value standard resistor. Record the resistance of this resistor as Rs2. Perform a measurement according to the above measurement process to obtain the measured value s2. The value of Rs2 should be greater than the resistance of the highest-value ignition element that can be used in this model of electronic detonator.

[0073] Step A1.3: Calculate the conversion factor. The conversion factor k is calculated as follows: k = (Rs2 - Rs1) ÷ (s2 - s1).

[0074] Step A1.4: Write the conversion factor k into the chip.

[0075] Step A2: Actual measurement step. During actual production and use of electronic detonator modules, such as incoming material inspection at a detonator factory or single-shot testing of electronic detonators by on-site blasting personnel, the electronic detonator chip is used to accurately measure the resistance of the firing element.

[0076] Step A2.1: Actual measurement: Perform a measurement according to the above measurement process to obtain the measurement value S.

[0077] Step A2.2: Calculate the resistance. The formula for calculating the ignition element resistance, R, is: R = k × S - Rdson. Rdson is the nominal on-resistance of the NMOS ignition switch. This resistance is an order of magnitude smaller than the ignition element resistance. The difference between the nominal and actual values is significantly smaller, so it does not affect measurement accuracy.

[0078] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. The embodiments of this application and the features in the embodiments may be combined with each other in any manner unless there is a conflict.

Claims

1. An electronic detonator chip suitable for measuring the resistance of an ignition element, characterized in that: include: A constant current source, an amplifier, an analog-to-digital converter (ADC), a voltage comparator, a charge and discharge control circuit for an energy storage capacitor, an NMOS ignition switch, and an NMOS control circuit; the electronic detonator chip is electrically connected to an external ignition element and an energy storage capacitor; The output end of the constant current source is electrically connected to the positive electrode of the ignition element; The positive input of the amplifier is electrically connected to the positive electrode of the ignition element, the negative input of the amplifier is electrically connected to the chip ground, and the output of the amplifier is electrically connected to the analog-to-digital converter ADC; The positive input of the voltage comparator is connected to the signal after the voltage is divided by the VCHG pin of the chip, and the negative input of the voltage comparator is connected to the reference voltage signal; One end of the energy storage capacitor charge and discharge control circuit is electrically connected to the chip VCHG pin, and the other end of the energy storage capacitor charge and discharge control circuit is electrically connected to the chip ground; The positive electrode of the ignition element and one end of the energy storage capacitor are electrically connected to the VCHG pin of the chip, the other end of the energy storage capacitor is electrically connected to the chip ground, the negative electrode of the ignition element is connected to the drain of the NMOS ignition switch, the source of the NMOS ignition switch is electrically connected to the chip ground, and the NMOS control circuit is electrically connected to the gate of the NMOS ignition switch.

2. The electronic detonator chip suitable for measuring the resistance of an ignition element according to claim 1, characterized in that: The gain range of the amplifier is set according to the acquisition range of the analog-to-digital converter ADC, and the output signal of the amplifier is placed in the middle of the input range of the analog-to-digital converter ADC.

3. The electronic detonator chip suitable for measuring the resistance of an ignition element according to claim 1, characterized in that: A zero adjustment switch is provided in the amplifier, and the zero adjustment switch is used to short-circuit the positive input and the negative input of the amplifier.

4. The electronic detonator chip suitable for measuring the resistance of an ignition element according to claim 1, characterized in that: The positive input of the voltage comparator is connected to the VCHG pin of the chip through a voltage divider circuit, and the voltage divider circuit includes a resistor R1 and a resistor R2, one end of the resistor R2 is connected to the VCHG pin of the chip, the other end of the resistor R2 is electrically connected to one end of the resistor R1 and the positive input of the voltage comparator, and the other end of the resistor R1 is electrically connected to the chip ground; The resistance relationship between the resistor R1 and the resistor R2 is: R2=9R1.

5. The electronic detonator chip suitable for measuring the resistance of an ignition element according to claim 1, characterized in that: It also includes a PMOS ignition switch and a PMOS control circuit; The PMOS control circuit is electrically connected to the gate of the PMOS ignition switch, the source of the PMOS ignition switch is electrically connected to the chip VCHG pin, the positive electrode of the ignition element is electrically connected to the drain of the PMOS ignition switch, and the ignition element is connected or disconnected to the chip VCHG pin through the PMOS ignition switch.

6. The electronic detonator chip suitable for measuring the resistance of an ignition element according to claim 1, characterized in that: The NMOS ignition switch is arranged on the periphery of the electronic detonator chip, and the NMOS ignition switch is electrically connected to the pins arranged on the electronic detonator chip.

7. A method for measuring the resistance of an ignition element, based on the electronic detonator chip suitable for measuring the resistance of an ignition element according to any one of claims 1 to 6, characterized in that: include: Step S1: turning on the energy storage capacitor charge and discharge control circuit to discharge the energy storage capacitor; Step S2: disconnecting the energy storage capacitor charge and discharge control circuit, and determining whether the residual voltage of the energy storage capacitor is less than a safety value through a voltage comparator. If so, proceed to step S3; if not, terminate the measurement. Step S3: starting the constant current source to output current to the positive electrode of the ignition element; turning on the NMOS ignition switch through the NMOS control circuit; Step S4: closing the zeroing switch in the amplifier, starting the analog-to-digital converter ADC, performing multiple samplings, and recording the average value; Step S5: disconnecting the zeroing switch in the amplifier, restarting the analog-to-digital converter ADC, performing multiple samplings, and recording the average value; Step S6: turning off the constant current source, disconnecting the NMOS firing switch through the NMOS control circuit, and turning on the energy storage capacitor charge and discharge control circuit to discharge the energy storage capacitor; Step S7: Subtract the two average values to obtain the measured resistance of the ignition element, and calculate the real resistance R of the ignition element according to the preset conversion coefficient.

8. The method for measuring the resistance of an ignition element according to claim 7, wherein: In step S3 to step S5, the voltage comparator is always used to determine whether the residual voltage of the energy storage capacitor is less than the safety value. If so, the measurement continues; if not, the measurement ends.

9. The method for measuring the resistance of an ignition element according to claim 7, wherein: The method further includes a calibration step, wherein the calibration step comprises: replacing the ignition element with two standard resistors of known resistance, and executing steps S1 to S7 to obtain measured values of the standard resistors and calculate a conversion factor k; k=(Rs2-Rs1)÷(s2-s1) Wherein, Rs1 represents the standard resistance value of the first standard resistor, and s1 represents the measured resistance value of the first standard resistor; Rs2 represents the standard resistance value of the second standard resistor, and s2 represents the measured resistance value of the second standard resistor; Updated the conversion factors in the electronic detonator chip.

10. The method for measuring the resistance of an ignition element according to claim 9, characterized in that: The calculation formula for the actual resistance R of the ignition element is: R=k×S-Rdson Where S is the measured resistance of the ignition element, and Rdson is the nominal value of the on-resistance of the NMOS ignition switch.

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