Numerical control electronic ignition circuit

Abstract

A numerical control electronic ignition circuit belongs to the technical field of electronic circuits. A conventional numerical control electronic ignition circuit needs to occupy four IO ports of a microprocessor, and in some working occasions (such as electronic fireworks and oxygen blasting), one microprocessor needs to control N ignition channels at the same time, so that a microprocessor with not less than 4N IO ports needs to be used. According to the utility model, the capacitor charging circuit, the capacitor discharging circuit and the ignition resistor circuit detection are integrated on one IO-A port, and an ignition control IO-B port is added, so that only two IO ports are needed, N ignition channels are controlled to have 2N IO ports, and the requirement on microprocessor resources can be reduced.

Description

Technical Field

[0001] This utility model belongs to the field of electronic circuit technology, specifically relating to a numerically controlled electronic ignition circuit for ignition of a resistance heating wire, such as in electronic fireworks, oxygen explosion, numerically controlled detonators, and other devices. Background Technology

[0002] A CNC electronic ignition circuit consists of four basic parts: charging, discharging, ignition resistor open-circuit detection, and ignition. A typical CNC electronic ignition circuit requires four I / O ports on a microprocessor. In some applications (such as electronic fireworks or oxygen explosion), a single microprocessor needs to control N ignition channels simultaneously, necessitating a microprocessor with at least 4N I / O ports. Utility Model Content

[0003] The purpose of this invention is to address the shortcomings of existing technologies by providing a numerical control electronic ignition circuit that integrates the capacitor charging circuit, capacitor discharging circuit, and ignition resistor open circuit detection into a single IO-A port, plus an ignition control IO-B port. This requires only two IO ports, thus enabling the control of N ignition channels with 2N IO ports.

[0004] This utility model's CNC electronic ignition circuit includes a charging section 1, a discharging section 2, an ignition resistor open circuit detection section 3, and an ignition section 4, with the following electrical connections:

[0005] The emitter of PNP transistor Q1 is connected to V+, the base is connected to the drain of NMOS transistor Q2, and the collector is connected to one end of resistor R5.

[0006] The other end of R5 is connected to the positive terminal of electrolytic capacitor C1, and the negative terminal of C1 is connected to GND.

[0007] One end of resistor R1 is connected to V+, and the other end of R1 is connected to the base of Q1;

[0008] The gate of Q2 is connected to the microprocessor power supply VCC, the source is connected to one end of resistor R2, and the other end of R2 is connected to the microprocessor's IO-A.

[0009] The gate of NMOS transistor Q3 is connected to IO-A, the source is connected to GND, and the drain is connected to the collector of Q1.

[0010] One end of resistor R4 is connected to IO-A and the other end is connected to VCC;

[0011] One end of resistor R3 is connected to IO-A, and the other end is connected to the positive terminal of diode D1;

[0012] The negative terminal of D1 is connected to one end of the ignition resistor R6, and the other end of R6 is connected to the positive terminal of C1.

[0013] The gate of NMOS transistor Q4 is externally connected to the microprocessor's IO-B, the source is connected to GND, the drain is connected to one end of R6, and the other end of R6 is connected to the positive terminal of C1.

[0014] This invention utilizes a microprocessor-controlled circuit. The microprocessor's I / O-A port is responsible for driving C1 to charge (low level), discharge (high level), and detecting the open circuit of ignition resistor R6 (reading status). The microprocessor's I / O-B port is responsible for controlling the ignition of R6 (high level).

[0015] Charging operation principle: When IO-B is set to low level, Q1 uses a PNP transistor to effectively limit the charging current (0.2mA-1mA). When IO-A = 0, Q2 and Q1 are turned on, and the other end of R5 charges the positive terminal of C1.

[0016] Discharge circuit working principle: When IO-B is set to low level, and IO-A = 1, Q1 and Q2 are turned off, Q3 is turned on, and discharge is performed to the positive terminal of C1 through R5.

[0017] Ignition resistor R6 is open-circuit detected; IO-B is set low. Discharge (IO-A = 1) waits for a certain period, then IO-A switches to read mode. The transient voltage at the positive terminal of C1 is low, transmitted to IO-A through ignition resistor R6, and the voltage at IO-A is read as low. If the ignition resistor is open-circuited, IO-A is pulled high by R4. After reading the status, IO-A switches back to high-level output (discharge state).

[0018] Working principle of charging and ignition: After the positive terminal of C1 is fully charged, 1O-B is set to high level, the drain of Q4 is pulled to low level, and the positive terminal of C1 discharges to the ignition resistor R6.

[0019] Circuit characteristics;

[0020] 1. If Q1 and Q4 are short-circuited, after the voltage is divided between ignition resistors R6 and R5, the energy divided by R6 will not reach the ignition temperature, and false ignition will not occur.

[0021] 2. When the discharge circuit is working, R5 can effectively prevent Q3 from being damaged by overcurrent.

[0022] Compared with the prior art, the beneficial effect of this utility model is that it can reduce the requirements for microprocessor resources. Attached Figure Description

[0023] Figure 1 This is the electrical schematic diagram of the circuit of this utility model. Detailed Implementation

[0024] The circuit structure is shown below. Figure 1 The specifications and parameters of each component are as follows:

[0025] Microprocessor model: MSP430FR2355; IO-A and IO-B are its general purpose I / O ports.

[0026]

[0027]

Claims

1. A numerically controlled electronic ignition circuit, characterized in that... It includes a charging section (1), a discharging section (2), an ignition resistor open circuit detection section (3), and an ignition section (4): The emitter of PNP transistor Q1 is connected to V+, the base is connected to the drain of NMOS transistor Q2, and the collector is connected to one end of resistor R5. The other end of R5 is connected to the positive terminal of electrolytic capacitor C1, and the negative terminal of C1 is connected to GND. One end of resistor R1 is connected to V+, and the other end of R1 is connected to the base of Q1; The gate of Q2 is connected to the microprocessor power supply VCC, the source is connected to one end of resistor R2, and the other end of R2 is connected to the microprocessor's IO-A. The gate of NMOS transistor Q3 is connected to IO-A, the source is connected to GND, and the drain is connected to the collector of Q1. One end of resistor R4 is connected to IO-A and the other end is connected to VCC; One end of resistor R3 is connected to IO-A, and the other end is connected to the positive terminal of diode D1; The negative terminal of D1 is connected to one end of the ignition resistor R6, and the other end of R6 is connected to the positive terminal of C1. The gate of NMOS transistor Q4 is externally connected to the microprocessor's IO-B, the source is connected to GND, the drain is connected to one end of R6, and the other end of R6 is connected to the positive terminal of C1.

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