Circuit for accurately judging ignition capacitor capacity of electronic detonator
By designing a circuit including energy storage capacitors, constant current source, voltage comparator, digital-to-analog converter and NMOS tube, and directly detecting the electronic control module through the external bus, the problem of difficulty in accurately judging the capacity of the electronic detonator fire capacitor in the prior art is solved, the reliability and consistency of the product is improved, and the accuracy of the explosion rate and safety of the blasting are improved.
Patent Information
- Application Number
- CN202421191055.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-28
- Publication Date
- 2025-06-10
- Estimated Expiration
- 2034-05-28
AI Technical Summary
The prior art is difficult to accurately judge the capacity of the electronic detonator ignition capacitor, resulting in poor ignition reliability, which can easily lead to blind guns or blasting failures, increasing safety risks.
Design a circuit, including energy storage capacitors outside the chip, constant current source inside the chip, voltage comparator, digital-to-analog converter and NMOS tube, directly detect the electronic control module through the external bus, and calculate and convert the capacitance capacity.
It realizes that the thermal capacitor capacity is accurately judged when the finished electronic control module is detected, which improves the reliability and consistency of the product, and improves the accuracy of blasting rate and safety of blasting.
Smart Images
Figure CN222965320U_ABST
Abstract
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 capacitance of the ignition capacitor of an electronic detonator. Background Technique
[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 element stores the detonator identity information, has the function of detonator initiation control or initiation delay time control, can test the on-off state of the ignition element, and can communicate with the initiation controller and other external control devices. Its ignition control principle is: by sending an instruction to open the switch, the energy stored in the ignition capacitor in the module is converted into heat through the energy conversion element, thereby igniting the primer to achieve ignition.
[0003] The ignition capacitor refers to the capacitor used for energy storage in the electronic control module. At present, although there are various types of ignition capacitors, such as electrolytic capacitors, tantalum capacitors, solid capacitors, etc., the main parameters determining the energy storage of the capacitor are the capacitance of the capacitor and the withstand voltage value of the capacitor. At present, the capacitance of the ignition capacitor is generally between 33uF - 110uF, and the maximum withstand voltage of the ignition capacitor is between 10V - 25V. The total amount of capacitor storage mainly depends on the voltage value of the capacitor and its own capacitance value at the moment of capacitor discharge. The lower the capacitance, the worse the ignition reliability. The blasting reliability and safety often depend on the ignition capacitor with the lowest capacitance. If the capacitance is too low, it is easy to cause ignition failure and form a misfire, resulting in blasting failure or increasing safety risks. Therefore, being able to accurately judge the capacitance of the ignition capacitor is one of the important means to improve the detonation rate and safety.
[0004] The capacitance of the capacitor is related to the specific specification model of the capacitor. After selecting the product model, the capacitance is fixed. However, due to the fact that the production process of the capacitor cannot be completely consistent, the capacitance of the capacitor generally fluctuates up and down after leaving the factory. If each capacitor is measured for its capacitance once before the patch production of the electronic control module, the production cost will be greatly increased. Content of the Utility Model
[0005] The technical problem to be solved by the utility model is to provide a circuit and method for accurately judging the capacitance of the electronic detonator capacitor, which can eliminate the products with capacitance lower than the permitted value during the detection of the finished electronic control module, increase the reliability and consistency of the products, and thus improve the detonation rate and safety of blasting.
[0006] To solve the above technical problems, the solution of the utility model is as follows:
[0007] A circuit for accurately judging the capacitance of the firing capacitor of an electronic detonator, comprising an energy storage capacitor placed outside the chip, and a constant current source, a voltage comparator, a digital-to-analog converter and an NMOS transistor placed inside the chip. The energy storage capacitor is electrically connected to the constant current source, the voltage comparator is electrically connected to the digital-to-analog converter, the NMOS transistor is electrically connected to the energy storage capacitor, and the constant current source is electrically connected to the voltage comparator.
[0008] Preferably, a first resistor is arranged between the energy storage capacitor and the NMOS transistor.
[0009] Preferably, a second resistor, a third resistor and a fourth resistor are sequentially arranged between the energy storage capacitor and the voltage comparator.
[0010] Preferably, the constant current of the constant current source is 500 μA.
[0011] Preferably, the accuracy of the digital-to-analog converter is 8 bit.
[0012] Preferably, the internal resistance of the NMOS transistor is less than 0.2 Ω.
[0013] Compared with the prior art, the beneficial effects of the present utility model are as follows:
[0014] The present utility model does not directly contact both ends of the firing capacitor through an external device for capacitance detection, but directly detects the electronic control module through an external bus, and calculates and converts to obtain the capacitance value, which simplifies the operation, reduces the process, improves the efficiency, and improves the consistency, reliability and safety of the product. Description of the Drawings
[0015] Figure 1 It is a schematic circuit diagram of the present utility model. Detailed Embodiments
[0016] The following further describes the detailed embodiments of the present utility model with reference to the drawings. It should be noted here that the description of these embodiments is for helping to understand the present utility model, but does not constitute a limitation to the present utility model. In addition, the technical features involved in the various embodiments of the present utility model described below can be combined with each other as long as they do not conflict with each other.
[0017] Refer to Figure 1 , a circuit for accurately judging the capacitance of the firing capacitor of an electronic detonator according to the present utility model, comprising an energy storage capacitor 1 placed outside the chip, and a constant current source 2, a voltage comparator 3, a digital-to-analog converter 4 and an NMOS transistor 5 placed inside the chip. The energy storage capacitor 1 is electrically connected to the constant current source 2, the voltage comparator 3 is electrically connected to the digital-to-analog converter 4, the NMOS transistor 5 is electrically connected to the energy storage capacitor 1, and the constant current source 2 is electrically connected to the voltage comparator 3.
[0018] A first resistor 7 is provided between the energy storage capacitor 1 and the NMOS transistor 5.
[0019] A second resistor 8, a third resistor 9, and a fourth resistor 10 are sequentially provided between the energy storage capacitor 1 and the voltage comparator 3.
[0020] The constant current of the constant current source 1 is 500 uA.
[0021] The precision of the digital-to-analog converter 4 is 8 bits.
[0022] The internal resistance of the NMOS transistor 5 is less than 0.2 Ω.
[0023] The working principle of the circuit of the present utility model is as follows:
[0024] When measuring the capacitance of the energy storage capacitor (C1) 1, first, through the discharge command, the DISCHAGE signal outputs a high level, the NMOS transistor (Q2) 5 conducts, CHAEGE_ON outputs a low level, the charging circuit is turned off, the discharge circuit is turned on, and the electric quantity of the energy storage capacitor (C1) 1 is released;
[0025] After the electric quantity of the energy storage capacitor (C1) 1 is released, by setting the voltage command, the digital-to-analog converter (DAC) 4 outputs a fixed voltage value (this value is determined during chip calibration), and then through the detection command of the specific energy storage capacitor (C1) 1, the DISCHAGE signal outputs a low level, the NMOS transistor (Q2) 5 is cut off, and at the same time CHAEGE_ON outputs a high level, and the energy storage capacitor (C1) 1 is charged with a constant current of 500 uA. At the beginning, the voltage of the energy storage capacitor (C1) 1 is low, the voltage at pin 5 of the voltage comparator (U1B) 3 is lower than that at pin 6, and the voltage comparator (U1B) 3 outputs a low level to the digital part of the chip. When the charging voltage reaches a certain value, the voltage comparator (U1B) 3 flips and outputs a high level to the digital part, that is, the charging completion signal.
[0026] We set the minimum allowable capacitance of the firing capacitor to be 65 uF, and electronic control module products with capacitors lower than 65 uF are all defined as unqualified.
[0027] We set the current of the constant current source (I1) 2 to be 1 mA, and the set VT is 18 V.
[0028] If the measured charging time is 1188.0 mS.
[0029] Then the capacitance: C = 1 * 1188.8 / 18 = 66.0 uF.
[0030] When the utility model is tested, external equipment is not required. The electronic control module can be directly detected by the detection equipment, and the capacitance of the firing capacitor can be measured. In the past, either single-piece measurement was carried out before chip mounting, but the cost was high and the process was complicated. Or no detection was carried out, relying on the factory quality standard of the capacitor manufacturer to reduce the probability of quality failure of the electronic control module by restricting the quality of the manufacturer. However, the product quality problem still cannot be completely solved because after the electronic control module is produced, the two ends of the capacitor cannot be directly contacted by equipment for measurement. The utility model does not directly contact the two ends of the firing capacitor through an external device for capacitance detection, but directly detects the electronic control module through an external bus, and calculates and converts to obtain the capacitance of the capacitor. The operation is simplified, the process is reduced, the efficiency is improved, and the consistency, reliability and safety of the product are improved.
[0031] The embodiments of the present utility model have been described in detail above in conjunction with the accompanying drawings, but the present utility model is not limited to the described embodiments. For those skilled in the art, without departing from the principle and spirit of the present utility model, various changes, modifications, substitutions and variations of these embodiments still fall within the protection scope of the present utility model.
Claims
1. A circuit for accurately determining the ignition capacitance of an electronic detonator, characterized in that: The invention comprises an energy storage capacitor (1) arranged outside the chip, and a constant current source (2), a voltage comparator (3), a digital-to-analog converter (4) and an NMOS tube (5) arranged inside the chip, wherein the energy storage capacitor (1) is electrically connected to the constant current source (2), the voltage comparator (3) is electrically connected to the digital-to-analog converter (4), the NMOS tube (5) is electrically connected to the energy storage capacitor (1), and the constant current source (2) is electrically connected to the voltage comparator (3).
2. The circuit for accurately judging the ignition capacitance of an electronic detonator according to claim 1, characterized in that: A first resistor (7) is provided between the energy storage capacitor (1) and the NMOS tube (5).
3. The circuit for accurately judging the ignition capacitance of an electronic detonator according to claim 1 is characterized in that: A second resistor (8), a third resistor (9) and a fourth resistor (10) are arranged in sequence between the energy storage capacitor (1) and the voltage comparator (3).
4. The circuit for accurately judging the ignition capacitance of an electronic detonator according to claim 1, characterized in that: The constant current of the constant current source (2) is 500uA.
5. The circuit for accurately judging the ignition capacitance of an electronic detonator according to claim 1, characterized in that: The accuracy of the digital-to-analog converter (4) is 8 bits.
6. The circuit for accurately judging the ignition capacitance of an electronic detonator according to claim 1, characterized in that: The internal resistance of the NMOS tube (5) is less than 0.2Ω.