Charging circuit and charging calibration method for electronic detonator

Abstract

The present invention provides a charging circuit and charging calibration method for electronic detonators, including an initiator, an electronic detonator chip, a test host, a third resistor voltage divider, an isolation amplifier and an energy storage capacitor; the initiator is connected to the electronic detonator chip and the test host respectively; the test host is connected to the electronic detonator chip and the isolation amplifier respectively; the isolation amplifier is connected to the third resistor voltage divider; the third resistor voltage divider is connected to the electronic detonator chip and the energy storage capacitor respectively; the energy storage capacitor is grounded. The present invention adopts the simplest resistor voltage divider and comparator circuit structure, utilizes the fact that the target charging voltage of the capacitor in the electronic detonator application has only a limited number of gears (10V, 16V, 20V, 25V) and the electronic detonator has a storage function, designs a simple and feasible calibration circuit and realizes high-precision charging of the electronic detonator energy storage capacitor through the calibration method.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic detonators, and in particular to a charging circuit and a charging calibration method for electronic detonators, and in particular to a high-precision charging circuit and method for electronic detonators. Background Art

[0002] Electronic detonator chips are used in the blasting industry. When the chip is communicating normally, it is powered by the power supply bus. When the chip enters the final delayed detonation process, the power supply bus may be broken by the detonator that detonates first, and the electronic detonator module cannot be powered. Therefore, the electronic detonator module has a dedicated energy storage capacitor to power the detonator after detonation. In addition to ensuring the normal operation of the electronic detonator chip during the detonation delay stage, this energy storage capacitor must also release enough energy at the end of the delay to ensure reliable ignition of the charge head.

[0003] Therefore, the energy storage capacitor needs to be charged before detonation, and the choice of the charging voltage of the capacitor will select the rated voltage of the energy storage capacitor used to maximize the utilization of the energy stored in the capacitor. Combining the energy requirements of the energy storage capacitor of the electronic detonator and the rated voltage specifications of the capacitor commonly used in the market, in fact, the charging voltage of the capacitor only needs to support a few limited gears such as 10V, 16V, 20V, 25V, etc.

[0004] Among the existing devices and technologies, most use a comparator to determine whether the capacitor is fully charged. The comparison voltage is generated by resistor voltage division. Due to the resistor accuracy and process differences, an error of about 10% may be introduced, and the resulting comparison voltage accuracy is also low. Taking 25V as the highest voltage, for example, the charging voltage error will be 2-3V; there are also multi-bit digital-to-analog converters DAC to generate a reference voltage as a comparison voltage, which can obtain relatively high accuracy. Taking 25V as the highest voltage, for example, a 5-bit DAC can obtain an accuracy of about 0.75V, but the implementation circuit of this method is complex and the chip cost is high.

[0005] The patent document with publication number CN101464115A discloses a charging control method for an electronic detonator blasting network, which includes a charging control process for an electronic detonator blasting device and a charging control process for an electronic detonator. The blasting device sends a charging instruction to the electronic detonator. After receiving the instruction, the detonator compares the detonator identity code in the instruction with the identity code of the detonator read by the logic control circuit: if they are the same, the detonator sends a charging instruction response back to the blasting device and enters the charging state; if they are different, the charging process is exited and the detonator continues to wait for external instructions. After the blasting device receives the response information sent back, it sets the detonator status flag to a charging success flag inside it. The above charging instruction is composed of a preset number M of synchronous learning heads, a charging control command word and an identity code of an electronic detonator in sequence.

[0006] Therefore, it is necessary to propose a new technical solution to improve the above technical problems. Summary of the invention

[0007] In view of the defects in the prior art, an object of the present invention is to provide a charging circuit and a charging calibration method for an electronic detonator.

[0008] A charging circuit for an electronic detonator provided by the present invention comprises an initiator, an electronic detonator chip, a test host, a third resistor voltage divider, an isolation operational amplifier and an energy storage capacitor;

[0009] The detonator is connected to the electronic detonator chip and the test host respectively; the test host is connected to the electronic detonator chip and the isolation operational amplifier respectively; the isolation operational amplifier is connected to the third resistor voltage divider; the third resistor voltage divider is connected to the electronic detonator chip and the energy storage capacitor respectively; the energy storage capacitor is grounded.

[0010] Preferably, the electronic detonator chip includes a reference power supply, a first resistor voltage divider, a communication circuit, a charge and discharge control circuit, a logic control circuit, an EEPROM, a charge current limiting resistor, a calibration circuit, a comparator circuit, and a second resistor voltage divider;

[0011] The reference power supply is connected to the first resistance voltage divider; the first resistance voltage divider is connected to the calibration circuit; the calibration circuit is respectively connected to the logic control circuit and the comparator circuit; the logic control circuit is respectively connected to the communication circuit, EEPROM, comparator circuit and charge and discharge control circuit; the comparator circuit is connected to the second resistance voltage divider; the charge and discharge control circuit is connected to the charging current limiting resistor; the second resistance voltage divider is respectively connected to the charging current limiting resistor and the energy storage capacitor; the charging current limiting resistor is connected to the energy storage capacitor.

[0012] Preferably, the detonator is an electronic detonator detonation controller, which communicates with the electronic detonator chip via two buses;

[0013] The test host is a host computer used to calibrate the electronic detonator chip, and communicates with the electronic detonator through two buses; the test host sends a charging instruction to the electronic detonator chip, measures the voltage of the energy storage capacitor through the measurement path, and adjusts the calibration parameters to adjust the charging voltage to the target value;

[0014] The third resistor divider divides the voltage of the energy storage capacitor, and the output is sent to the test host for measurement after passing through the isolation amplifier;

[0015] The voltage follower operational amplifier circuit of the isolation operational amplifier, and the third resistor voltage-dividing path does not affect the second resistor voltage-dividing path inside the electronic detonator chip through the isolation operational amplifier.

[0016] Preferably, the reference power supply is a low-voltage reference power supply generated inside the electronic detonator chip based on high-voltage input, and outputs 3V;

[0017] The first resistor divider divides the reference voltage to output a reference voltage signal corresponding to the voltage charging gear, which is used as a comparison reference for the comparator after being calibrated by the calibration circuit;

[0018] The communication circuit is a circuit inside the electronic detonator that completes the communication function with the initiator, and is responsible for receiving instructions from the initiator and returning data to the initiator;

[0019] The charging and discharging control circuit is a control circuit for charging and discharging the energy storage capacitor, comprising a charging MOS tube and a discharging MOS tube, and the switching signals of the charging MOS tube and the discharging MOS tube are controlled by a logic control circuit;

[0020] The logic control circuit is a digital logic control circuit inside the electronic detonator chip, which controls the charge and discharge paths based on the output result of the comparator; stores the parameters in the EEPROM based on the calibration result; and reads the calibration parameters from the EEPROM during charging to perform calibration before charging;

[0021] The EEPROM is a memory inside the electronic detonator chip that can be repeatedly erased and written for multiple times and is used to store calibration parameters.

[0022] Preferably, the charging current limiting resistor limits the capacitance when charging the energy storage capacitor;

[0023] The calibration circuit generates a corresponding control signal based on the calibration parameters read from the EEPROM by the logic control circuit, and outputs the corresponding reference voltage to the comparator circuit.

[0024] The comparator circuit compares the signal after the resistance voltage division of the energy storage capacitor with the reference voltage output by the calibration circuit, and outputs a high level if the signal is higher than the reference voltage, otherwise, it outputs a low level;

[0025] The second resistor divider divides the voltage of the energy storage capacitor and outputs the voltage to the comparator as a signal to be compared.

[0026] The present invention also provides a charging calibration method for an electronic detonator, the method using the above-mentioned charging circuit for an electronic detonator, the method comprising the following steps:

[0027] Step S1: During the electronic detonator chip packaging test phase, the test host supplies power to the electronic detonator chip through the bus;

[0028] Step S2: the test host sends a charging gear configuration instruction to the electronic detonator chip;

[0029] Step S3: The test host sends a charging instruction and continuously reads the status information of the fully charged state inside the electronic detonator chip. After it is fully charged, the voltage value V_CAP of the energy storage capacitor is measured through the third resistor voltage division and isolation op-amp path. There is a 12-bit analog-to-digital conversion ADC inside the test host, which can achieve a measurement accuracy of 6 mV. The test host compares the measured voltage value of the energy storage capacitor with the target voltage V_TARGET of the charging instruction. If |V_CAP - V_TARGET| < THD, it means that the charging voltage meets the preset gear, and the current operation is completed, and step S5 is performed;

[0030] Step S4: If the error of the capacitor charging voltage is too large, |V_CAP - V_TARGET| >= THD, then adjust the calibration control word to finely adjust the reference voltage inside the chip;

[0031] Step S5: Write the calibration control word CHG_CTRL that meets the current charging voltage into the EEPROM memory inside the electronic detonator chip, and it will not be lost when power is off;

[0032] Step S6: If all charging gears have been calibrated, then end; otherwise, repeat steps S2 - S5.

[0033] Preferably, in step S2, according to several gears supported by the electronic detonator chip, charging is carried out one by one from low to high.

[0034] Preferably, THD in step S3 is the error threshold, taking 0.25V.

[0035] Preferably, the method of fine adjustment in step S4 is as follows:

[0036] Step S4.1: If V_CAP > V_TARGET, then adjust CHG_CTRL; if CHG_CTRL > 0, then CHG_CTRL = CHG_CTRL - 1; otherwise, CHG_CTRL has been adjusted to the lowest and no longer adjusted;

[0037] Step S4.2: If V_CAP < V_TARGET, then adjust CHG_CTRL; if CHG_CTRL < 4, then CHG_CTRL = CHG_CTRL + 1; otherwise, CHG_CTRL has been adjusted to the highest and no longer adjusted;

[0038] Step S4.3: After adjusting CHG_CTRL, repeat step S3.

[0039] Preferably, in step S5, for the 3-bit calibration control word CHG_CTRL, 5 fine-tuning gears can be selected, each gear is 0.025V, and the voltage error on the energy storage capacitor is: 0.025x10=0.25V; the error after adjustment does not exceed 0.25V.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] 1. The present invention adopts the simplest circuit structure of resistor voltage divider and comparator, utilizes the fact that the target charging voltage of the capacitor in the electronic detonator application has only a limited number of gears (10V, 16V, 20V, 25V) and the electronic detonator has a storage function, designs a simple and feasible calibration circuit and realizes high-precision charging of the electronic detonator energy storage capacitor through the calibration method;

[0042] 2. The parameters used for circuit calibration in the present invention can be permanently stored in the storage medium inside the electronic detonator and will not be lost when power is off;

[0043] 3. When the electronic detonator receives a charging instruction, the present invention automatically loads the corresponding parameters for real-time calibration;

[0044] 4. The present invention utilizes the characteristics that the electronic detonator chip has internal storage function and only needs to support a limited number of charging gears. A small amount of calibration circuit is added to the traditional circuit structure of resistor voltage divider and comparator. The calibration parameters are obtained by calibration method during the chip packaging and testing stage and written into the internal memory, thereby realizing high-precision charging of the energy storage capacitor during actual blasting;

[0045] 5. The circuit structure of the present invention is simple, and the charging voltage accuracy is extremely high, with an error of no more than 0.25V;

[0046] 6. The present invention can maximize the use of the energy of the energy storage capacitor by high-precision charging of the energy storage capacitor, ensure that the electronic detonator can ignite reliably, and prevent the detonator from refusing to explode; at the same time, it can also prevent the capacitor voltage from being too high due to low charging accuracy and the safety problems caused by capacitor damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0048] Figure 1 It is a circuit composition structure diagram of the present invention;

[0049] Figure 2 This is a schematic diagram of the first resistor voltage division and calibration circuit of the present invention. DETAILED DESCRIPTION

[0050] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments 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 of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0051] Embodiment 1:

[0052] A charging circuit for an electronic detonator provided by the present invention comprises an initiator, an electronic detonator chip, a test host, a third resistor voltage divider, an isolation operational amplifier and an energy storage capacitor.

[0053] The detonator is connected to the electronic detonator chip and the test host respectively; the test host is connected to the electronic detonator chip and the isolation amplifier respectively; the isolation amplifier is connected to the third resistor voltage divider; the third resistor voltage divider is connected to the electronic detonator chip and the energy storage capacitor respectively; the energy storage capacitor is grounded.

[0054] The electronic detonator chip comprises a reference power supply, a first resistor voltage divider, a communication circuit, a charge and discharge control circuit, a logic control circuit, an EEPROM, a charge current limiting resistor, a calibration circuit, a comparator circuit, and a second resistor voltage divider.

[0055] The reference power supply is connected to the first resistor voltage divider; the first resistor voltage divider is connected to the calibration circuit; the calibration circuit is respectively connected to the logic control circuit and the comparator circuit; the logic control circuit is respectively connected to the communication circuit, the EEPROM, the comparator circuit and the charge and discharge control circuit; the comparator circuit is connected to the second resistor voltage divider; the charge and discharge control circuit is connected to the charging current limiting resistor; the second resistor voltage divider is respectively connected to the charging current limiting resistor and the energy storage capacitor; the charging current limiting resistor is connected to the energy storage capacitor.

[0056] The detonator is an electronic detonator detonation controller, which communicates with the electronic detonator chip through two buses; the test host is a host computer used to calibrate the electronic detonator chip, and communicates with the electronic detonator through two buses; the test host sends a charging instruction to the electronic detonator chip, and measures the voltage of the energy storage capacitor through a measurement path, and adjusts the calibration parameters to adjust the charging voltage to a target value; the third resistor divider divides the voltage of the energy storage capacitor, and the output is sent to the test host for measurement after passing through an isolation amplifier; the voltage follower operational amplifier circuit of the isolation amplifier, the third resistor divider path does not affect the second resistor divider path inside the electronic detonator chip through the isolation amplifier.

[0057] The reference power supply is a low-voltage reference power supply generated based on high-voltage input inside the electronic detonator chip, and outputs 3V; the first resistor divider divides the reference voltage, and outputs a reference voltage signal corresponding to the voltage charging gear, which is used as a comparison reference for the comparator after calibration by the calibration circuit; the communication circuit is a circuit inside the electronic detonator that completes the communication function with the initiator, and is responsible for receiving initiator instructions and returning data to the initiator; the charge and discharge control circuit is a control circuit for charging and discharging the energy storage capacitor, including a charging MOS tube and a discharging MOS tube, and the switching signals of the charging MOS tube and the discharging MOS tube are controlled by the logic control circuit; the logic control circuit is a digital logic control circuit inside the electronic detonator chip, and controls the charge and discharge path based on the output result of the comparator; the parameters are stored in the EEPROM based on the calibration result; the calibration parameters are read from the EEPROM during charging for calibration and then charged; the EEPROM is a memory inside the electronic detonator chip that can be repeatedly erased and written many times, and is used to store the calibration parameters.

[0058] The charging current limiting resistor limits the capacitance when the energy storage capacitor is charged; the calibration circuit generates a corresponding control signal based on the calibration parameters read from the EEPROM by the logic control circuit, and outputs it to the calibration circuit to select the corresponding reference voltage to the comparator circuit; the comparator circuit compares the signal after the resistance voltage division of the energy storage capacitor with the reference voltage output by the calibration circuit, and outputs a high level if it is higher than the reference voltage, otherwise, it outputs a low level; the second resistance voltage division divides the voltage of the energy storage capacitor and outputs it to the comparator as the signal to be compared.

[0059] The present invention also provides a charging calibration method for an electronic detonator, the method using the above-mentioned charging circuit for an electronic detonator, the method comprising the following steps:

[0060] Step S1: During the electronic detonator chip packaging test phase, the test host supplies power to the electronic detonator chip through the bus.

[0061] Step S2: the test host sends a charging gear configuration instruction to the electronic detonator chip; charging is performed one by one from low to high according to several gears supported by the electronic detonator chip.

[0062] Step S3: The test host sends a charging instruction and continuously reads the status information of the fully charged state inside the electronic detonator chip. After it is fully charged, the voltage value V_CAP of the energy storage capacitor is measured through the third resistor voltage division and isolation operational amplifier path. There is a 12-bit analog-to-digital converter ADC inside the test host, which can achieve a measurement accuracy of 6 mV. The test host compares the measured voltage value of the energy storage capacitor with the target voltage V_TARGET of the charging instruction. If |V_CAP - V_TARGET| < THD is satisfied, it means that the charging voltage meets the preset gear, and the current operation is completed, and step S5 is performed; THD is the error threshold, taking 0.25V.

[0063] Step S4: If the error of the capacitor charging voltage is too large, |V_CAP - V_TARGET| >= THD, then adjust the calibration control word to fine-tune the reference voltage inside the chip. The fine-tuning method is as follows:

[0064] Step S4.1: If V_CAP > V_TARGET, then adjust CHG_CTRL; if CHG_CTRL > 0, then CHG_CTRL = CHG_CTRL - 1; otherwise, CHG_CTRL has been adjusted to the lowest and no further adjustment is made.

[0065] Step S4.2: If V_CAP < V_TARGET, then adjust CHG_CTRL; if CHG_CTRL < 4, then CHG_CTRL = CHG_CTRL + 1; otherwise, CHG_CTRL has been adjusted to the highest and no further adjustment is made.

[0066] Step S4.3: After adjusting CHG_CTRL, repeat step S3.

[0067] Step S5: Write the calibration control word CHG_CTRL that meets the current charging voltage into the EEPROM memory inside the electronic detonator chip, and it will not be lost when powered off; for the 3-bit calibration control word CHG_CTRL, 5 fine-tuning gears can be selected, each gear is 0.025V, and the corresponding voltage error on the energy storage capacitor is: 0.025 x 10 = 0.25V; the error after adjustment does not exceed 0.25V.

[0068] Step S6: If all charging gears have been calibrated, then end; otherwise, repeat steps S2 - S5.

[0069] Embodiment 2:

[0070] Embodiment 2 is a preferred example of Embodiment 1 to more specifically illustrate the present invention.

[0071] The present invention provides a high-precision charging circuit and method for electronic detonators. The invention adopts the simplest circuit structure of resistor voltage divider and comparator, utilizes the characteristics that the target charging voltage of capacitors in electronic detonator applications has only a limited number of gears (10V, 16V, 20V, 25V) and the electronic detonator has a storage function, designs a simple and feasible calibration circuit and realizes high-precision charging of the electronic detonator energy storage capacitor through a calibration method. At the same time, the parameters used for circuit calibration can be permanently stored in the storage medium inside the electronic detonator, and will not be lost when the power is off. When the electronic detonator receives a charging instruction, the corresponding parameters are automatically loaded for real-time calibration.

[0072] The present invention provides a high-precision charging circuit for an electronic detonator, comprising:

[0073] Detonator: Electronic detonator detonation controller, communicates with the electronic detonator chip through the second bus.

[0074] Reference power supply: A low-voltage reference power supply generated inside the electronic detonator chip based on high-voltage input, with an output of 3V.

[0075] Charge and discharge control circuit: The control circuit for charging and discharging the energy storage capacitor mainly includes charging and discharging MOS tubes. The switching signal of the MOS tube is controlled by the logic control circuit.

[0076] Charging current limiting resistor: used to limit the capacitance when charging the energy storage capacitor, about 2Kohm.

[0077] The first resistor divider divides the reference voltage and outputs a reference voltage signal corresponding to the voltage charging gear, which is used as a comparison reference for the comparator after calibration by the calibration circuit.

[0078] The second resistor divider divides the voltage of the energy storage capacitor and outputs it to the comparator as a signal to be compared.

[0079] Calibration circuit: The logic control circuit generates a corresponding control signal based on the calibration parameters read from the EEPROM, and outputs it to the calibration circuit to select the corresponding reference voltage for the comparator circuit.

[0080] Comparator circuit: compares the signal after resistance voltage division of the energy storage capacitor with the reference voltage output by the calibration circuit. If it is higher than the reference voltage, it outputs a high level, otherwise, it outputs a low level.

[0081] Logic control circuit: The digital logic control circuit inside the detonator chip controls the charge and discharge paths based on the output of the comparator; stores the parameters in the EEPROM based on the calibration results; and reads the calibration parameters from the EEPROM during charging to calibrate and then charge.

[0082] EEPROM: A memory inside the electronic detonator chip that can be repeatedly erased and written to and can be used to store calibration parameters.

[0083] Communication circuit: The circuit inside the electronic detonator that completes the communication function with the detonator, which is mainly responsible for receiving instructions from the detonator and returning data to the detonator.

[0084] Test host: The host computer used to calibrate the chip, which also communicates with the electronic detonator through the second bus. It is used to send charging instructions to the electronic detonator chip, measure the voltage of the energy storage capacitor through the measurement path, and then adjust the calibration parameters to adjust the charging voltage to the target value.

[0085] The third resistor divider divides the voltage of the energy storage capacitor, and the output is sent to the test host for measurement after passing through the isolation amplifier.

[0086] Isolation op amp: A voltage follower operational amplifier circuit that prevents the third resistor voltage divider path from affecting the second resistor voltage divider path inside the chip.

[0087] The first resistor divider circuit inputs a 3V reference voltage, and the entire resistor divider circuit consists of 21 resistors. The minimum resistance is 0.25R, the total resistance is 30R, and the R value is above 10Mohm. The resistor divider reference outputs are mainly 1.0V, 1.6V, 2.0V, and 2.5V, which correspond to the energy storage capacitors of 10V, 16V, 20V, and 25V, respectively, because the second resistor divider circuit uses a 1 / 10 resistor divider circuit.

[0088] Through the 3-bit calibration control word CHG_CTRL, 10V, 16V, 20V, and 25V can be fine-tuned. Each charging gear has 5 fine-tuning gears to choose from, and the adjustment range is 0.025x10=0.25V. The default value of CHG_CTRL is 2, corresponding to the standard gear. The configuration range is 0, 1, 2, 3, 4, corresponding to the 5 fine-tuning gears respectively.

[0089] The 2-bit charging gear control CHG_SEL selects one of the four gears (1.0V, 1.6V, 2.0V, 2.5V) as the reference voltage of the comparator according to the charging gear command sent by the detonator.

[0090] Implementation principle refinement:

[0091] To achieve high-precision charging of electronic detonators, it is first necessary to calibrate the charging voltage of each gear. The calibration process can be performed during the chip packaging test to obtain the appropriate configuration parameters.

[0092] The charging voltage calibration process includes the following steps:

[0093] Step 1: In the chip packaging and testing stage, the test host powers the electronic detonator chip through the bus to complete the power supply of the electronic detonator chip.

[0094] Step 2: The test host sends a charging gear configuration instruction to the electronic detonator chip. This is carried out one by one from low to high according to several gears supported by the chip.

[0095] Step 3: The test host sends a charging instruction and continuously reads the state information of the internal full charge of the electronic detonator chip. Once it is fully charged, the voltage value V_CAP of the energy storage capacitor is measured through the third resistor voltage division and isolation operational amplifier path. There is a 12-bit digital-to-analog conversion ADC inside the test host, which can achieve a measurement accuracy of 6mV. The test host compares the measured energy storage capacitor voltage value with the target voltage (V_TARGET) of the charging instruction. If |V_CAP - V_TARGET| < THD (THD is defined as the error threshold, taking 0.25V), it means that the charging voltage meets the preset gear, and the current operation is completed, then proceed to Step 5.

[0096] Step 4: If the capacitor charging voltage error is too large, |V_CAP - V_TARGET| >= THD, then adjust the calibration control word to finely adjust the reference voltage inside the chip. The fine adjustment method is as follows:

[0097] If V_CAP > V_TARGET, then adjust CHG_CTRL. If CHG_CTRL > 0, then CHG_CTRL = CHG_CTRL - 1; otherwise, CHG_CTRL has been adjusted to the lowest and no further adjustment is made.

[0098] If V_CAP < V_TARGET, then adjust CHG_CTRL. If CHG_CTRL < 4, then CHG_CTRL = CHG_CTRL + 1; otherwise, CHG_CTRL has been adjusted to the highest and no further adjustment is made.

[0099] After adjusting CHG_CTRL, repeat Step 3.

[0100] Step 5: Write the calibration control word CHG_CTRL that meets the current charging voltage into the EEPROM memory inside the electronic detonator chip, and it will not be lost when the power is off. For the 3-bit calibration control word CHG_CTRL, there are 5 fine-tuning gears to choose from, each gear being 0.025V, corresponding to a voltage error on the energy storage capacitor of: 0.025 x 10 = 0.25V. So the error after adjustment does not exceed 0.25V.

[0101] Step 6: If all charging gears have been calibrated, then end; otherwise, repeat Steps 2 - 5.

[0102] After the above calibration, the electronic detonator chip has stored the charging voltage calibration word CHG_CTRL in the memory inside the chip. When the electronic detonator is actually exploded, the calibration word is loaded from the memory to complete the fine adjustment of the charging voltage, so that the error between the actual voltage after charging and the expected charging capacitance of the capacitor is less than 0.25V. The specific process is as follows:

[0103] Actual blasting process of electronic detonator:

[0104] Step 1: In the actual blasting of the electronic detonator, the initiator supplies power to the electronic detonator chip through the bus to complete the power supply of the electronic detonator chip. After the chip is powered on, the corresponding calibration control word will be automatically loaded from the EEPROM.

[0105] Step 2: The detonator performs normal scanning, chip configuration, delay time setting, detonation password verification, and other operations on the electronic detonator chip, and then confirms the status. If everything is normal, it sends a capacitor charging instruction. Otherwise, repeat steps 1 and 2.

[0106] Step 3: The detonator reads the charging status of the capacitor, and after confirming that it is fully charged, sends a detonation command.

[0107] Step 4: After the electronic detonator chip receives the detonation command, the chip enters the delay mode of the countdown before detonation.

[0108] Step 4: After the timer counts down to zero, an ignition control signal is output to detonate the charge head.

[0109] The present invention utilizes the characteristics that the electronic detonator chip has a storage function and only needs to support a limited number of charging gears. A small amount of calibration circuit is added to the traditional circuit structure of resistor voltage divider and comparator. The calibration parameters are obtained by calibration method during the chip packaging and testing stage and written into the internal memory, thereby realizing high-precision charging of the energy storage capacitor during actual blasting. The circuit structure of the method is simple, and the charging voltage accuracy is extremely high, with an error of no more than 0.25V.

[0110] By charging the energy storage capacitor with high precision, the energy of the energy storage capacitor can be utilized to the greatest extent, ensuring that the electronic detonator can ignite reliably and preventing the detonator from refusing to explode; at the same time, it can also prevent the capacitor voltage from being too high due to low charging accuracy and safety problems caused by capacitor damage.

[0111] Those skilled in the art may understand this embodiment as a more specific description of Embodiment 1.

[0112] Those skilled in the art know that, in addition to realizing the system and its various devices, modules, and units provided by the present invention in a purely computer-readable program code, it is entirely possible to realize the same functions in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system and its various devices, modules, and units provided by the present invention can be considered as a hardware component, and the devices, modules, and units included therein for realizing various functions can also be regarded as structures within the hardware component; the devices, modules, and units for realizing various functions can also be regarded as both software modules for realizing the method and structures within the hardware component.

[0113] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A charging circuit for an electronic detonator, characterized in that: It includes an initiator, an electronic detonator chip, a test host, a third resistor voltage divider, an isolation amplifier and an energy storage capacitor; The detonator is connected to the electronic detonator chip and the test host respectively; the test host is connected to the electronic detonator chip and the isolation amplifier respectively; the isolation amplifier is connected to the third resistor voltage divider; the third resistor voltage divider is connected to the electronic detonator chip and the energy storage capacitor respectively; the energy storage capacitor is grounded; The electronic detonator chip includes a reference power supply, a first resistor voltage divider, a communication circuit, a charge and discharge control circuit, a logic control circuit, an EEPROM, a charging current limiting resistor, a calibration circuit, a comparator circuit, and a second resistor voltage divider; The reference power supply is connected to the first resistor voltage divider; the first resistor voltage divider is connected to the calibration circuit; the calibration circuit is respectively connected to the logic control circuit and the comparator circuit; the logic control circuit is respectively connected to the communication circuit, the EEPROM, the comparator circuit and the charge and discharge control circuit; the comparator circuit is connected to the second resistor voltage divider; the charge and discharge control circuit is connected to the charging current limiting resistor; the second resistor voltage divider is respectively connected to the charging current limiting resistor and the energy storage capacitor; the charging current limiting resistor is connected to the energy storage capacitor; The reference power supply is a low-voltage reference power supply generated inside the electronic detonator chip based on high-voltage input, and outputs 3V; The first resistor divider divides the reference voltage to output a reference voltage signal corresponding to the voltage charging gear, which is used as a comparison reference for the comparator after being calibrated by the calibration circuit; The communication circuit is a circuit inside the electronic detonator that completes the communication function with the initiator, and is responsible for receiving instructions from the initiator and returning data to the initiator; The charging and discharging control circuit is a control circuit for charging and discharging the energy storage capacitor, comprising a charging MOS tube and a discharging MOS tube, and the switching signals of the charging MOS tube and the discharging MOS tube are controlled by a logic control circuit; The logic control circuit is a digital logic control circuit inside the electronic detonator chip, which controls the charge and discharge paths based on the output result of the comparator; stores the parameters in the EEPROM based on the calibration result; and reads the calibration parameters from the EEPROM during charging to perform calibration before charging; The EEPROM is a memory inside the electronic detonator chip that can be repeatedly erased and written multiple times and is used to store calibration parameters; The charging current limiting resistor limits the capacitance when charging the energy storage capacitor; The calibration circuit generates a corresponding control signal based on the calibration parameters read from the EEPROM by the logic control circuit, and outputs the corresponding reference voltage to the comparator circuit. The comparator circuit compares the signal after the resistance voltage division of the energy storage capacitor with the reference voltage output by the calibration circuit, and outputs a high level if the signal is higher than the reference voltage, otherwise, it outputs a low level; The second resistor divider divides the voltage of the energy storage capacitor and outputs the voltage to the comparator as a signal to be compared.

2. The charging circuit for electronic detonators according to claim 1, characterized in that: The detonator is an electronic detonator detonation controller, which communicates with the electronic detonator chip via two buses; The test host is a host computer used for calibrating the electronic detonator chip, communicating with the electronic detonator through a two-wire bus; the test host sends a charging instruction to the electronic detonator chip, measures the voltage of the energy storage capacitor through a measurement path, and adjusts the calibration parameters to adjust the charging voltage to the target value; The third resistor divides the voltage of the energy storage capacitor, and the output is sent to the test host for measurement after passing through the isolation operational amplifier; The voltage follower operational amplifier circuit of the isolation operational amplifier, and the third resistor voltage division path does not affect the second resistor voltage division path inside the electronic detonator chip through the isolation operational amplifier.

3. A charging calibration method for an electronic detonator, characterized in that: The method applies the charging circuit for electronic detonators described in any one of claims 1-2, and the method includes the following steps: Step S1: In the packaging test stage of the electronic detonator chip, the test host supplies power to the electronic detonator chip through the bus to supply power to the electronic detonator chip; Step S2: The test host sends a charging gear configuration instruction to the electronic detonator chip; Step S3: The test host sends a charging instruction and continuously reads the state information that the internal charging of the electronic detonator chip is full. After being fully charged, the voltage value V_CAP of the energy storage capacitor is measured through the third resistor voltage division and isolation operational amplifier path. There is a 12-bit analog-to-digital converter ADC inside the test host, which can achieve a measurement accuracy of 6 mV. The test host compares the measured energy storage capacitor voltage value with the target voltage V_TARGET of the charging instruction. If |V_CAP - V_TARGET| < THD, it means that the charging voltage meets the preset gear, completes the current operation, and proceeds to step S5; Step S4: If the error of the capacitor charging voltage is too large, |V_CAP - V_TARGET| >= THD, then adjust the calibration control word to finely adjust the reference voltage inside the chip; Step S5: Write the calibration control word CHG_CTRL that meets the current charging voltage into the EEPROM memory inside the electronic detonator chip, and it will not be lost when the power is off; Step S6: If all charging gears have been calibrated, then end; otherwise, repeat steps S2 - S5.

4. The charging calibration method for electronic detonators according to claim 3, characterized in that: In step S2, charging is performed one by one from low to high according to several gears supported by the electronic detonator chip.

5. The charging calibration method for electronic detonators according to claim 3, characterized in that: THD in step S3 is the error threshold, taking 0.25 V.

6. The charging calibration method for electronic detonators according to claim 3, characterized in that: The method of fine adjustment in step S4 is as follows: Step S4.1: If V_CAP > V_TARGET, then adjust CHG_CTRL; if CHG_CTRL > 0, then CHG_CTRL = CHG_CTRL - 1; otherwise, CHG_CTRL has been adjusted to the lowest and no longer adjusted; Step S4.2: If V_CAP < V_TARGET, then adjust CHG_CTRL; if CHG_CTRL < 4, then CHG_CTRL = CHG_CTRL + 1; otherwise, CHG_CTRL has been adjusted to the highest and no longer adjusted; After adjusting CHG_CTRL, repeat step S3.

7. The charging calibration method for electronic detonators according to claim 3, characterized in that: In step S5, for the 3-bit calibration control word CHG_CTRL, 5 fine-tuning gears can be selected, each gear is 0.025V, and the voltage error on the energy storage capacitor is: 0.025x10=0.25V; the error after adjustment does not exceed 0.25V.

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