Double-layer protection control circuit

Abstract

The utility model discloses a double-layer protection control circuit comprising a single-chip microcomputer which is connected with a capacitor C24. The capacitor C24 is connected with a resistor R29, and the resistor R29 is connected with a bidirectional diode Q9; the bidirectional diode Q9 is connected with a capacitor C9, and the capacitor C9 is connected with an MOS tube Q11; and the MOS tube Q11 is connected with the optocoupler U3A. The beneficial effects of the utility model are that when the single-chip microcomputer fails, the single-chip microcomputer outputs a high level C24 all the time, the C24 cannot be charged, the Q11 cannot reach the conduction condition of the Q11, the single-chip microcomputer outputs a low level all the time, and the conduction condition of the Q11 cannot be met, so that the potential safety hazard caused by the failure of the single-chip microcomputer can be prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of switch power supplies, in particular to a double-layer protection control circuit. Background Art

[0002] During the actual use of the switching power supply, if the charger microcontroller fails, it will cause damage to the battery pack and even cause an explosion, endangering personal safety.

[0003] At present, the control circuit is mainly controlled by a single-chip microcomputer. If the single-chip microcomputer fails and breaks down, the output port may have a high voltage or a low voltage, causing the control circuit to fail. The output voltage exceeds the maximum voltage of the battery pack. The battery pack itself cannot shut down. If the battery is overcharged for a long time, the battery temperature will rise sharply and the battery may explode and cause harm. Therefore, a double-layer protection control circuit is proposed. Summary of the invention

[0004] The purpose of the utility model is to provide a double-layer protection control circuit to solve the problems raised in the above background technology.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] A double-layer protection control circuit includes a single-chip microcomputer, wherein the single-chip microcomputer is connected to a capacitor C24;

[0007] The capacitor C24 is connected to the resistor R29, and the resistor R29 is connected to the bidirectional diode Q9;

[0008] The bidirectional diode Q9 is connected to the capacitor C9, and the capacitor C9 is connected to the MOS tube Q11;

[0009] The MOS tube Q11 is connected to the optical coupler U3A.

[0010] Furthermore, the single chip microcomputer is connected to the capacitor C24 via the VCC CTL port.

[0011] Furthermore, the bidirectional diode Q9 is of model ISS226.

[0012] Furthermore, the capacitor C9 is connected to the resistor R71, and the resistor R71 is connected to the MOS transistor Q11.

[0013] Furthermore, the resistor R71 is connected to pin 1 and pin 3 of the MOS tube Q11 respectively.

[0014] Furthermore, pin 2 of the MOS tube Q11 is connected to pin 2 of the optocoupler U3A.

[0015] Furthermore, pin 1 of the optocoupler U3A is connected to resistor R67.

[0016] Compared with the prior art, the beneficial effects of the utility model are:

[0017] When the microcontroller fails, the microcontroller always outputs a high level, C24 will not charge C9, and Q11 will not meet the conditions for Q11 to turn on. The microcontroller always outputs a low level and also cannot meet the conditions for Q11 to turn on, which can prevent safety hazards caused by the failure of the microcontroller. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a circuit diagram of the utility model. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0020] Embodiment 1:

[0021] Please refer to Figure 1, the utility model provides a technical solution:

[0022] A double-layer protection control circuit includes a single-chip microcomputer, the single-chip microcomputer is connected to a capacitor C24, the capacitor C24 is connected to a resistor R29, the resistor R29 is connected to a bidirectional diode Q9, the bidirectional diode Q9 is connected to the capacitor C9, the capacitor C9 is connected to a MOS tube Q11, and the MOS tube Q11 is connected to an optical coupler U3A.

[0023] like Figure 1 As shown: connect the microcontroller to capacitor C24 through the VCC CTL port.

[0024] like Figure 1 As shown: The bidirectional diode Q9 model is ISS226.

[0025] like Figure 1 As shown: the capacitor C9 is connected to the resistor R71, so that the resistor R71 is connected to the MOS tube Q11, wherein the resistor R71 is respectively connected to the 1st pin and the 3rd pin of the MOS tube Q11.

[0026] like Figure 1 As shown: connect pin 2 of MOS tube Q11 to pin 2 of optocoupler U3A, and connect pin 1 of optocoupler U3A to resistor R67.

[0027] Working principle:

[0028] The on and off of the MOS tube Q11 is controlled by PWM. When the PWM waveform of the single-chip microcomputer is at a high level, the capacitor C24 is charged. When the PWM waveform is at a low level, the capacitor C24 is discharged. At this time, the resistor R29 is charged, and the MOS tube Q11 is turned on. The bidirectional diode Q9 prevents the capacitor C9 from charging C24 in reverse. In this way, the voltage on the capacitor C9 can be better maintained, so that the MOS tube Q11 is continuously turned on. When the single-chip microcomputer fails, the single-chip microcomputer always outputs a high level, and the capacitor C24 will not charge C9. The MOS tube Q11 cannot meet the conditions for conduction. The single-chip microcomputer always outputs a low level and cannot meet the conduction conditions of the MOS tube Q11, which can prevent safety hazards caused by the failure of the single-chip microcomputer.

[0029] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A double-layer protection control circuit, including a single-chip microcomputer, characterized in that: The single chip microcomputer is connected to capacitor C24; The capacitor C24 is connected to the resistor R29, and the resistor R29 is connected to the bidirectional diode Q9; The bidirectional diode Q9 is connected to the capacitor C9, and the capacitor C9 is connected to the MOS tube Q11; The MOS tube Q11 is connected to the optical coupler U3A.

2. A double-layer protection control circuit according to claim 1, characterized in that: The single chip microcomputer is connected to the capacitor C24 via the VCCCTL port.

3. A double-layer protection control circuit according to claim 1, characterized in that: The bidirectional diode Q9 is of model ISS226.

4. A double-layer protection control circuit according to claim 1, characterized in that: The capacitor C9 is connected to the resistor R71, and the resistor R71 is connected to the MOS transistor Q11.

5. A double-layer protection control circuit according to claim 4, characterized in that: The resistor R71 is connected to the pin 1 and the pin 3 of the MOS tube Q11 respectively.

6. A double-layer protection control circuit according to claim 5, characterized in that: Pin 2 of the MOS tube Q11 is connected to pin 2 of the optocoupler U3A.

7. A double-layer protection control circuit according to claim 1, characterized in that: Pin 1 of the optocoupler U3A is connected to resistor R67.

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