Power supply output voltage rapid drop circuit

Abstract

The utility model discloses a power supply output voltage rapid drop circuit. The input end of the rectifier bridge DB1 receives mains supply voltage, the output end of the rectifier bridge DB1 is connected with the grid electrode of the MOS tube Q2 through a resistor R2 and a resistor R5 in sequence, the source electrode of the MOS tube Q2 is grounded, and the drain electrode of the MOS tube Q2 is connected with the cathode of the light emitting end of the optocoupler U1; the anode of the light-emitting end of the optocoupler U1 receives a voltage, the collector of the optocoupler U1 is connected with the anode of the AC / DC module through a resistor R1, and the emitter of the optocoupler U1 is grounded through a resistor R6; the circuit further comprises an MOS transistor Q1, the grid electrode of the MOS transistor Q1 is connected with the emitting electrode of the optocoupler U1 through a resistor R4, the source electrode of the MOS transistor Q1 is grounded, and the drain electrode of the MOS transistor Q1 is connected with the negative electrode of the AC / DC module. According to the circuit, the AC-to-DC output voltage can be rapidly reduced after the mains supply switch is switched off, and code clearing of the wireless module is easily achieved through switching on and switching off of the switch.

Description

Technical Field

[0001] The utility model relates to the field of LED power supplies, in particular to a power supply output voltage rapid drop circuit. Background Art

[0002] With the development of Internet of Things technology, LED wireless intelligent dimming / color adjustment power supply has also been widely used. In general, LED wireless intelligent dimming power supply needs to be connected to the mobile phone to configure various parameters through the APP. Basically, all Internet of Things manufacturers detect the number of times the power supply voltage of the module is quickly turned on and off to allow the mobile phone APP to discover and connect the power supply device. In some applications, due to the limitation of space size, such as magnetic guide rail power supply, it is necessary to adopt a high-power AC / DC constant voltage power supply with multiple DC / DC power supplies. The wireless control module is placed on the DC / DC power supply board, and the LED power supply is controlled through the mobile phone APP or other switches and wireless modules. The purpose of dimming / color adjustment is finally achieved. Since the output capacitance of the high-power AC / DC power supply is relatively large, after the mains switch is turned off, the output voltage of the AC to DC power supply will remain for a long time, resulting in the DC / DC power supply connected to the AC / DC cannot be quickly powered off, and the wireless control module on the DC / DC cannot be cleared by the on and off of the switch. Once the wireless control module has been bound to a device, it will be difficult to be re-bound to a new device. Utility Model Content

[0003] In order to solve the above problems, the present technical solution provides a power supply output voltage fast drop circuit.

[0004] To achieve the above purpose, the technical solution is as follows:

[0005] A power supply output voltage fast drop circuit, comprising:

[0006] A rectifier bridge DB1, wherein the input end of the rectifier bridge DB1 receives the mains voltage, and the output end is connected to the gate of the MOS tube Q2 through the resistor R2 and the resistor R5 in sequence, the source of the MOS tube Q2 is grounded, and the drain is connected to the cathode of the light-emitting end of the optocoupler U1;

[0007] The anode of the light-emitting end of the optical coupler U1 receives a voltage, the collector thereof is connected to the positive electrode of the AC / DC module through the resistor R1, and the emitter thereof is grounded through the resistor R6;

[0008] It also includes a MOS tube Q1, whose gate is connected to the emitter of the optical coupler U1 through a resistor R4, whose source is grounded, and whose drain is connected to the negative electrode of the AC / DC module.

[0009] In some embodiments, the gate of the MOS transistor Q2 is also grounded through the capacitor C1, the resistor R7 and the diode ZD2.

[0010] In some embodiments, a resistor R3 is disposed between the drain of the MOS tube Q2 and the cathode of the light-emitting end of the optocoupler U1 .

[0011] In some embodiments, the resistor R6 is further connected in parallel with a diode ZD2.

[0012] The beneficial effects of this application are:

[0013] The present application provides a circuit that can allow the AC to DC output voltage to drop rapidly after the mains switch is turned off, and the wireless module can be easily cleared by opening and closing the switch. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following briefly introduces the drawings required for describing the embodiments.

[0015] Figure 1 It is a structural schematic diagram of an embodiment of the utility model. DETAILED DESCRIPTION

[0016] In order to make the technical problems, technical solutions and beneficial effects solved by the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0017] Please refer to Figure 1 As shown, a power supply output voltage fast drop circuit includes:

[0018] A rectifier bridge DB1, wherein the input end of the rectifier bridge DB1 receives the mains voltage, and the output end is connected to the gate of the MOS tube Q2 through the resistor R2 and the resistor R5 in sequence, the source of the MOS tube Q2 is grounded, and the drain is connected to the cathode of the light-emitting end of the optocoupler U1;

[0019] The anode of the light-emitting end of the optical coupler U1 receives a voltage, the collector thereof is connected to the positive electrode of the AC / DC module through the resistor R1, and the emitter thereof is grounded through the resistor R6;

[0020] It also includes a MOS tube Q1, whose gate is connected to the emitter of the optical coupler U1 through a resistor R4, whose source is grounded, and whose drain is connected to the negative electrode of the AC / DC module.

[0021] In this embodiment, the gate of the MOS transistor Q2 is also grounded through the capacitor C1, the resistor R7 and the diode ZD2.

[0022] In this embodiment, a resistor R3 is provided between the drain of the MOS tube Q2 and the cathode of the light-emitting end of the optical coupler U1 .

[0023] In this embodiment, the resistor R6 is further connected in parallel with a diode ZD2.

[0024] A voltage signal sampling circuit is added to the positive and negative ends of the rectifier bridge DB1 of the AC / DC power supply, which is composed of R2, R3, R5, R7, C1, ZD2, and Q2. A shutdown circuit is added to the secondary side of the AC / DC power supply, which is composed of R1, R4, R6, ZD1, and Q1. The two resistors are connected through the optocoupler U1, where VDD is the auxiliary power supply for the primary side, and Vo+ and Vo- are the positive and negative outputs of the AC / DC. When there is voltage at the positive and negative ends of DB1, Q2 is turned on, current flows through the primary side of U1, current flows through the primary side of the optocoupler U1, and current is sensed on the secondary side of U1. Q1 is driven to turn on by the circuit on the secondary side, and the positive and negative outputs of the AC / DC are connected to the output circuit of the AC / DC; when there is no voltage at the positive and negative ends of DB1, the optocoupler U1 is turned off, Q1 is turned off, the positive and negative outputs are disconnected from the output circuit of the AC / DC, and the positive and negative voltages drop to very low values ​​instantly, achieving the purpose of rapid drop in output voltage.

[0025] The above description is only a preferred embodiment of the present application and is not intended to limit the scope of implementation of the present application. Other principles and basic structures that are the same or similar to those of the present application are within the protection scope of the present application.

Claims

1. A power supply output voltage rapid drop circuit, characterized in that: include; A rectifier bridge DB1, wherein the input end of the rectifier bridge DB1 receives the mains voltage, and the output end is connected to the gate of the MOS tube Q2 through the resistor R2 and the resistor R5 in sequence, the source of the MOS tube Q2 is grounded, and the drain is connected to the cathode of the light-emitting end of the optocoupler U1; The anode of the light-emitting end of the optical coupler U1 receives a voltage, the collector thereof is connected to the positive electrode of the AC / DC module through the resistor R1, and the emitter thereof is grounded through the resistor R6; It also includes a MOS tube Q1, whose gate is connected to the emitter of the optical coupler U1 through a resistor R4, whose source is grounded, and whose drain is connected to the negative electrode of the AC / DC module.

2. A power supply output voltage rapid drop circuit according to claim 1, characterized in that: The gate of the MOS transistor Q2 is also grounded through the capacitor C1, the resistor R7 and the diode ZD2.

3. A power supply output voltage rapid drop circuit according to claim 2, characterized in that: A resistor R3 is provided between the drain of the MOS tube Q2 and the cathode of the light-emitting end of the optical coupler U1.

4. The power supply output voltage rapid drop circuit according to claim 1, characterized in that: The resistor R6 is further connected in parallel with a diode ZD2.

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