A circuit for enhancing the surge current resistance of detonator and electronic detonator

Abstract

The present invention discloses a circuit and an electronic detonator for enhancing the surge current resistance of detonators, the circuit comprising: a primary protection circuit, a secondary protection circuit, a tertiary protection circuit and a quaternary protection circuit connected in sequence, one end of the primary protection circuit is connected to the detonator AB leg line, the other end is connected to one end of the secondary protection circuit, the other end of the secondary protection circuit is connected to one end of the tertiary protection circuit, the other end of the tertiary protection circuit is connected to one end of the quaternary protection circuit, the other end of the quaternary protection circuit is connected to one end of the quaternary protection circuit, the other end of the quaternary protection circuit is connected to the detonator digital control chip; the primary protection circuit and the tertiary protection circuit are used to eliminate high-frequency and high-voltage transient currents, the secondary protection circuit is used to eliminate low-frequency and low-voltage large currents, and the quaternary protection circuit is used to prevent low-voltage and large currents from damaging digital chips. The present invention enhances the ability of the detonator module to resist surge currents, making it suitable for blasting in complex environments such as small sections. In addition, the present invention has mass production conditions and reduces the material cost of the detonator module.

Description

Technical Field

[0001] The invention relates to the technical field of electronic detonators, and in particular to a circuit for enhancing the surge current resistance of detonators and an electronic detonator. Background Art

[0002] Electronic detonators are new detonators that use digital control chips to precisely control the detonator process. Their advantages are: mature technology, better performance, and easy control. Their precise multi-stage delay setting provides feasible conditions for large-scale precision blasting. Their three-code binding technology enables closed-loop information processing during the specific use of electronic detonators, and intelligent and efficient safety supervision. However, during the actual blasting process, the first detonator to detonate will generate a huge shock wave. The high-energy electromagnetic interference and surge current it radiates will seriously affect the adjacent detonators, causing them to refuse to explode. This phenomenon is particularly obvious in small cross-section scenarios. This requires the detonator module itself to have a strong ability to resist electromagnetic interference and surge current.

[0003] The current electronic detonator module has the following disadvantages:

[0004] 1) The input AB pole protection capability of some detonator modules is limited and cannot be used in complex construction environments such as small sections;

[0005] 2) The input AB pole protection circuit design of some detonator modules is too complicated and expensive, which is not conducive to mass production;

[0006] 3) The components of the input AB pole protection circuit of some detonator modules are too large, which is not conducive to the miniaturization of detonators. Summary of the invention

[0007] The main purpose of the present invention is to provide a circuit and an electronic detonator for enhancing the surge current resistance of the detonator, aiming to improve the ability of the detonator module to resist electromagnetic interference and surge current.

[0008] To achieve the above-mentioned object, the present invention proposes a circuit for enhancing the surge current resistance of a detonator, comprising: a primary protection circuit, a secondary protection circuit, a tertiary protection circuit and a quaternary protection circuit connected in sequence, wherein one end of the primary protection circuit is connected to the A leg wire and the B leg wire of the detonator, and the other end is connected to one end of the secondary protection circuit, the other end of the secondary protection circuit is connected to one end of the tertiary protection circuit, the other end of the tertiary protection circuit is connected to one end of the quaternary protection circuit, and the other end of the quaternary protection circuit is connected to a detonator digital control chip;

[0009] The first-level protection circuit and the third-level protection circuit are used to eliminate high-frequency and high-voltage transient currents, the second-level protection circuit is used to eliminate low-frequency, low-voltage and high currents, and the fourth-level protection circuit is used to prevent low-voltage and high currents from damaging the digital chip.

[0010] A further technical solution of the present invention is that the primary protection circuit includes three pairs of internal tip discharge pads and four external tip discharge pads, which are used to eliminate high-frequency and high-voltage transient voltages in high-energy surges on the A and B legs of the detonator.

[0011] A further technical solution of the present invention is that the tip discharge pads within the pair are serrated, and the distance between the upper and lower pairs of pads is 0.12 mm.

[0012] A further technical solution of the present invention is that the outward pointed discharge pad is attached to the edge of the PCB board, and the distance between the pad and the metal shell of the detonator is 0.5 mm.

[0013] A further technical solution of the present invention is that the secondary protection circuit includes a TVS tube D1, and the TVS tube D1 is connected to the primary protection circuit and the tertiary protection circuit respectively, and is used to eliminate the low-frequency, low-voltage and high-current in the high-energy surge on the A leg and the B leg of the detonator.

[0014] A further technical solution of the present invention is that the three-level protection circuit is constructed using resistor R4, resistor R5, TVS tube D2, TVS tube D3 and a discharge shrapnel connected to the detonator metal tube shell, which is used to eliminate high-frequency and high-voltage pulse interference.

[0015] A further technical solution of the present invention is that the four-level protection circuit includes two fusible fuses connected in series in the A leg line and the B leg line of the detonator.

[0016] To achieve the above object, the present invention further provides an electronic detonator, comprising the circuit for enhancing the surge current resistance of the detonator as described above.

[0017] The beneficial effects of the circuit for enhancing the surge current resistance of detonators and the electronic detonator of the present invention are as follows: the present invention adopts a four-level protection circuit to enhance the ability of the detonator module to resist surge current, making it suitable for blasting in complex environments such as small cross-sections. In addition, the present invention has the conditions for mass production and reduces the material cost of the detonator module. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0019] Figure 1 It is a circuit structure schematic diagram of a preferred embodiment of a circuit for enhancing the surge current resistance of a detonator according to the present invention;

[0020] Figure 2 It is a schematic diagram of the low-frequency, low-voltage, high-current elimination path;

[0021] Figure 3 It is a schematic diagram of the high-frequency and high-voltage transient current elimination path.

[0022] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] The present invention proposes a circuit for enhancing the surge current resistance of detonators. The technical solution adopted by the present invention is mainly to design a set of four-level protection circuits to protect the detonator input AB level, greatly enhancing its ability to resist surge current. In the design process, a tip discharge circuit, a high-power TVS tube, an RC barrier and discharge circuit formed by a resistor plus a small package high-voltage TVS tube, a discharge shrapnel in contact with the tube shell, and a small fuse connected in series to a digital chip are introduced. High-energy surge currents mainly include high-frequency high-voltage transient currents and low-frequency low-voltage large currents. The first and third level protection circuits in the present invention mainly eliminate high-frequency high-voltage transient currents, the second level protection circuit mainly eliminates low-frequency low-voltage large currents, and the fourth level protection circuit prevents low-voltage large currents from directly damaging digital chips. The detonator module designed by us according to this scheme can stably pass the 20KV ESD test, 8KV high-voltage pulse test, 220V AC withstand voltage test, and 50V DC withstand voltage test under extreme conditions. The finished detonator is subjected to actual blasting tests in complex environments such as small sections, and the explosion rejection rate is less than three thousandths.

[0025] For details, please refer to Figure 1 The preferred embodiment of the circuit for enhancing the surge current resistance of detonators of the present invention includes a primary protection circuit, a secondary protection circuit, a tertiary protection circuit and a quaternary protection circuit connected in sequence.

[0026] Among them, one end of the first-level protection circuit is connected to the detonator A leg line and B leg line, and the other end is connected to one end of the second-level protection circuit, the other end of the second-level protection circuit is connected to one end of the third-level protection circuit, the other end of the third-level protection circuit is connected to one end of the fourth-level protection circuit, and the other end of the fourth-level protection circuit is connected to the detonator CNC chip.

[0027] The first-level protection circuit and the third-level protection circuit are used to eliminate high-frequency and high-voltage transient currents, the second-level protection circuit is used to eliminate low-frequency, low-voltage and high currents, and the fourth-level protection circuit is used to prevent low-voltage and high currents from damaging the digital chip.

[0028] like Figure 1 As shown, the primary protection circuit includes three pairs of internal tip discharge pads and four external tip discharge pads, which are used to eliminate high-frequency and high-voltage transient voltages in high-energy surges on the A and B legs of the detonator.

[0029] In this embodiment, the tip discharge pads in the pair are sawtooth-shaped, and the distance between the upper and lower pairs of pads is 0.12 mm.

[0030] In this embodiment, the outward pointed discharge pad is attached to the edge of the PCB board, and the distance between the pad and the metal shell of the detonator is 0.5 mm.

[0031] In this embodiment, the secondary protection circuit includes a TVS tube D1, which is connected to the primary protection circuit and the tertiary protection circuit respectively, and is used to eliminate the low-frequency, low-voltage and high-current in the high-energy surge on the A leg and the B leg of the detonator.

[0032] In this embodiment, the three-level protection circuit is constructed using resistors R4, R5, TVS tubes D2, D3 and discharge shrapnel connected to the metal tube shell of the detonator, and is used to eliminate high-frequency and high-voltage pulse interference.

[0033] In this embodiment, the four-level protection circuit includes two blown fuses connected in series in the A leg and the B leg of the detonator.

[0034] The working principle of the circuit for enhancing the surge current resistance of detonators of the present invention is described in detail below.

[0035] In the circuit for enhancing the surge current resistance of the detonator of the present invention, the "primary protection circuit" is mainly composed of three pairs of inward tip discharge pads and four outward tip discharge pads, and its main function is to eliminate the high-frequency and high-voltage transient current in the high-energy surge on the AB leg of the detonator. The inward tip discharge pad is designed to be sawtooth-shaped, and the spacing between the upper and lower pairs of pads is 0.12mm; the outward tip discharge pad is close to the edge of the PCB board, and the spacing with the metal shell of the detonator is about 0.5mm. This forms two better tip discharge paths. First, the surge current enters from the A pole (or the B pole) and is led out from the B pole (or the A pole) through the inward tip discharge pad; second, the surge current enters from the A pole or the B pole and is led out from the metal shell of the detonator to the ground through the outward tip discharge pad.

[0036] Specifically, for the three pairs of inner pointed discharge tubes: the high-frequency and high-voltage transient current enters from the A pole (or the B pole) and is derived from the B pole (or the A pole) through (PAD1, PDA2, PAD3); for the four outer pointed discharge tubes: the high-frequency and high-voltage transient current enters from the A pole (or the B pole) and is derived from the detonator metal shell through (PAD6, PAD7, PAD8, PAD10).

[0037] The "secondary protection circuit" is mainly composed of a high-power TVS tube. It can withstand 200W of power, 30KV of anti-ESD performance, and the SOD123 package can quickly dissipate heat. Its main function is to eliminate the low-frequency, low-voltage and high-current in the high-energy surge on the AB leg of the detonator. The high current enters from the A pole (or the B pole) and is led out from the B pole (or the A pole) through this high-power TVS tube to avoid damaging the next level circuit.

[0038] Specifically, low-frequency, low-voltage, and high-current enters from pole A (or pole B) and is discharged from pole B (or pole A).

[0039] The "three-level protection circuit" is mainly composed of a small series resistor (R4 R5), a small TVS tube (D2 D3) in parallel, and a metal discharge shrapnel (J1) connected to the pipe shell. This circuit structure is equivalent to a bidirectional RC low-pass filter circuit plus an electrostatic isolation discharge circuit. The filter circuit can eliminate high-frequency and high-voltage pulse interference; the discharge circuit can discharge high-frequency electrostatic interference to the ground at the fastest speed through the TVS tube and shrapnel.

[0040] Specifically:

[0041] 1) Bidirectional RC low-pass filter circuit: It is composed of the equivalent capacitance of R4 and D2, and the equivalent capacitance of R5 and D3, and mainly filters out high-frequency interference;

[0042] 2) Electrostatic isolation and discharge circuit: R4 and R5 block static electricity; in the electrostatic discharge circuit formed by D2, D3, and J1, the electrostatic interference signal enters from pole A (or pole B), is blocked by R4 and R5, and then discharged to the ground by D2, D3, and J1;

[0043] 3) Use 0402 package 51 ohm small resistor; 0402 package 30KV TVS tube; customized discharge spring.

[0044] The "four-level protection circuit" is mainly composed of two fuses connected in series in the AB line. It uses PTC devices with a reaction time of less than 1 millisecond. Once the high-current interference signal breaks through the protection of the first three-level protection circuit and is transmitted to the rear-stage circuit, the PTC device will fuse within milliseconds to block the high current. The control chip at the back end will not be damaged and can still maintain the established working state to control the detonator.

[0045] Specifically, this embodiment uses two small-packaged PTC fuses. Once a large surge current breaks through the first three levels of protection, PTC1 or PTC2 will blow within 1 millisecond to protect the subsequent CNC chip.

[0046] The implementation process of the circuit for enhancing the surge current resistance of detonators of the present invention is:

[0047] 1. If Figure 2 As shown, the low-frequency, low-voltage, and high-current elimination path is:

[0048] 1) Low-frequency, low-voltage, and high-current are discharged internally through three pairs of inner tip discharge pads and high-power TVS tubes; large current flows in from pole A (or pole B) and is discharged from pole B (or pole A).

[0049] 2) Low-frequency, low-voltage, and high current is discharged to the metal shell through four externally pointed discharge pads; the high current flows in from class A (or pole B) and is discharged by the shell.

[0050] 2. If Figure 3 As shown, the high-frequency and high-voltage transient current elimination path is:

[0051] 1) Discharge path 1: High-frequency and high-voltage transient current is discharged from the external tip discharge pad to the metal tube shell through the primary protection circuit;

[0052] 2) Discharge path 2: The high-frequency and high-voltage transient current is discharged to the metal shell through the metal shrapnel through the three-level barrier discharge path;

[0053] 3) Fuse path 3: High-frequency and high-voltage transient current blows the fuse in the fourth-level protection circuit.

[0054] The beneficial effect of the circuit for enhancing the surge current resistance of detonators of the present invention is that the present invention adopts a four-level protection circuit to enhance the ability of the detonator module to resist surge current, making it suitable for blasting in complex environments such as small cross-sections. In addition, the present invention has the conditions for mass production and reduces the material cost of the detonator module.

[0055] To achieve the above object, the present invention further proposes an electronic detonator, including the circuit for enhancing the detonator's surge current resistance as described above, which will not be described in detail here.

[0056] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A circuit for enhancing the surge current resistance of a detonator, characterized in that: include: A primary protection circuit, a secondary protection circuit, a tertiary protection circuit and a quaternary protection circuit connected in sequence, wherein one end of the primary protection circuit is connected to the A leg wire and the B leg wire of the detonator, and the other end is connected to one end of the secondary protection circuit, the other end of the secondary protection circuit is connected to one end of the tertiary protection circuit, the other end of the tertiary protection circuit is connected to one end of the quaternary protection circuit, and the other end of the quaternary protection circuit is connected to the detonator digital control chip; The first-level protection circuit and the third-level protection circuit are used to eliminate high-frequency and high-voltage transient currents, the second-level protection circuit is used to eliminate low-frequency, low-voltage and high-currents, and the fourth-level protection circuit is used to prevent low-voltage and high-currents from damaging the detonator digital control chip; The primary protection circuit includes three pairs of inner tip discharge pads and four outer tip discharge pads, which are used to eliminate high-frequency and high-voltage transient currents in high-energy surges on the A and B legs of the detonator; The secondary protection circuit includes a TVS tube D1, which is connected to the primary protection circuit and the tertiary protection circuit respectively. A low-frequency, low-voltage, and high-current enters from the A pole or the B pole, and is led out from the B pole or the A pole through the TVS tube D1, so as to eliminate the low-frequency, low-voltage, and high-current in the high-energy surge on the A leg and the B leg of the detonator; The three-level protection circuit is constructed by using resistors R4 and R5 connected in series, TVS tubes D2 and D3 connected in parallel, and a discharge shrapnel J1 connected to the metal shell of the detonator. The resistor R4 and the TVS tube D2 form an equivalent capacitor, and the resistor R5 and the TVS tube D3 form an equivalent capacitor. The electrostatic interference signal enters from the A pole or the B pole, is blocked by the resistor R4 and the resistor R5, and is then discharged to the ground by the TVS tube D2, the TVS tube D3, and the discharge shrapnel J1, so as to eliminate high-frequency and high-voltage pulse interference; The four-level protection circuit includes two blown fuses connected in series in the A leg and the B leg of the detonator.

2. The circuit for enhancing the surge current resistance of detonators according to claim 1, characterized in that: The tip discharge pads in the pair are sawtooth-shaped, and the distance between the upper and lower pairs of pads is 0.12 mm.

3. The circuit for enhancing the surge current resistance of detonators according to claim 2, characterized in that: The outward-facing tip discharge pad is close to the edge of the PCB board, and the distance between the tip discharge pad and the metal shell of the detonator is 0.5 mm.

4. An electronic detonator, characterized in that: A circuit for enhancing the surge current resistance of a detonator as claimed in any one of claims 1 to 3.

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