CN215835499U

CN215835499U - Voltage abnormity detection control circuit and voltage abnormity detection power supply

Info

Publication number: CN215835499U
Application number: CN202121786503.8U
Authority: CN
Inventors: 郁华春; 于龙飞
Original assignee: Sharp Electronics Research and Development Nanjing Co Ltd
Current assignee: Sharp Electronics Research and Development Nanjing Co Ltd
Priority date: 2021-08-03
Filing date: 2021-08-03
Publication date: 2022-02-15
Anticipated expiration: 2031-08-03

Abstract

The utility model provides a voltage abnormity detection control circuit, which comprises a No. 1 triode, a No. 2 triode, a No. 3 triode, a P-MOS and a Zener diode, wherein the P-MOS is connected with a power supply; the base electrode of the No. 1 triode is connected with the circuit enabling DET _ EN, and the emitter electrode of the No. 2 triode is connected with the monitoring voltage 12V through the Zener diode; the collector of the triode No. 1 is connected with the base of the triode No. 3; the collector of the No. 3 triode and the collector of the No. 2 triode are respectively connected with the grid of the P-MOS; the emitting electrode of the No. 1 triode, the emitting electrode of the No. 2 triode and the emitting electrode of the No. 3 triode (Q103) are grounded. The voltage abnormity detection control circuit provided by the utility model can detect when the monitoring voltage fluctuates, and outputs a signal DET _ OUT, and the system can be reset by using the signal, so that the television can automatically recover to be normal, can be built by itself only by using passive components, and has few devices and low cost.

Description

Voltage abnormity detection control circuit and voltage abnormity detection power supply

Technical Field

The utility model provides a voltage abnormity detection control circuit, and belongs to the technical field of electricity.

Background

At present, a power supply rectifying and filtering circuit generally comprises a fuse, a rectifier and an electrolytic capacitor, and because the electrolytic capacitor with the built-in power supply rectifying and filtering has the limitation of the highest working voltage, when the voltage of a power grid abnormally increases and exceeds the withstand voltage value of the power grid, the power grid rectifying and filtering circuit can burst to cause electrolyte and possibly burn to cause fire.

Taking a flat panel television as an example, whether the power supply in the flat panel television is safe or not is a main factor for determining whether the whole flat panel television is safe or not. Among the prior art flat screen television power AC rectification filter circuit includes: fuse, AC rectifier bridge, and filter electrolytic capacitor connected in series to the power grid circuit. The voltage of the power grid is rectified into direct current voltage after passing through the fuse and the rectifier bridge, and the direct current voltage is applied to two ends of the filtering electrolytic capacitor, and the polarity of the direct current voltage is positive at the top and negative at the bottom.

In the use process of the television, the power supply voltage of the main board fluctuates due to the instantaneous fluctuation of the alternating current power grid, so that some problems such as screen blackness, silence and the like of the system occur and the automatic recovery cannot be realized.

More seriously, when the grid voltage rises abnormally, the direct current voltage added at the two ends of the filter electrolytic capacitor also rises, after the direct current voltage exceeds the safety voltage, the electrolytic capacitor bursts and sprays electrolyte, but the electrolyte can not be completely short-circuited in the whole process, so the fuse can be rarely fused, the power supply is cut off rapidly, and the electrolyte sprayed by the electrolytic capacitor bursts and fires due to continuous accumulation of heat energy, so that the burning event of the flat-panel television is caused.

SUMMERY OF THE UTILITY MODEL

The technical problem is as follows: in order to solve the defects of the prior art, the utility model provides a voltage abnormity detection control circuit.

The technical scheme is as follows: the utility model provides a voltage abnormity detection control circuit, which comprises a No. 1 triode (Q101), a No. 2 triode (Q102), a No. 3 triode (Q103), a P-MOS (Q104) and a Zener diode (D101); the base electrode of the No. 1 triode (Q101) is connected with the circuit enabling DET _ EN, and the emitter electrode of the No. 2 triode (Q102) is connected with the monitoring voltage 12V through the Zener diode (D101); the collector of the No. 1 triode (Q101) is connected with the base of the No. 3 triode (Q103); the collector of the No. 3 triode (Q103) and the collector of the No. 2 triode (Q102) are respectively connected with the grid of the P-MOS (Q104); the emitter of the No. 1 triode (Q101), the emitter of the No. 2 triode (Q102) and the emitter of the No. 3 triode (Q103) are grounded.

As an improvement, an emitter of a No. 1 triode (Q101), an emitter of a No. 2 triode (Q102) and an emitter of a No. 3 triode (Q103) are connected with each other and are connected with a No. 5 resistor (R105) to be grounded; no. 3 resistance (R103) is connected between No. 1 triode (Q101), No. 3 triode (Q103), connects No. 4 resistance (R104) between No. 3 triode (Q103), P-MOS (Q104), connects No. 2 resistance (R102) between zener diode (D101) and external voltage DET _ EN.

Preferably, the detected voltage of the Zener diode (D101) is 8.2V, which can be adjusted according to actual conditions

The utility model also provides a voltage abnormity detection power supply for the LED display, the power supply circuit is connected with the voltage abnormity detection control circuit, the source electrode of the P-MOS (Q104), the resistor No. 3 (R103) and the resistor No. 4 (R104) are connected with the power supply circuit, and the drain electrode of the P-MOS (Q104) and the other end of the resistor No. 5 (R105) are connected with the detection signal.

Has the advantages that: the voltage abnormity detection control circuit provided by the utility model can detect voltage fluctuation, and output a signal, and the system can be reset by using the signal, so that a television can automatically recover to be normal, can be automatically built only by passive components, and has few components and low cost.

Drawings

Fig. 1 is a schematic structural diagram of a voltage abnormality detection control circuit according to the present invention.

Detailed Description

Some terms used below are to be interpreted:

5V: a constant electrical voltage.

DET _ EN: the switch of the detection circuit is turned on when the detection circuit is high and turned off when the detection circuit is low.

12V: the detected voltage.

DET _ OUT: the output level of the detection circuit is normally high, and the detection circuit is low when operating.

The present invention is further explained below.

The voltage abnormity detection control circuit comprises a No. 1 triode (Q101), a No. 2 triode (Q102), a No. 3 triode (Q103), a P-MOS (Q104) and a Zener diode (D101); the base electrode of the No. 1 triode (Q101) is connected with the circuit enabling DET _ EN, and the emitter electrode of the No. 2 triode (Q102) is connected with the monitoring voltage 12V through the Zener diode (D101); the collector of the No. 1 triode (Q101) is connected with the base of the No. 3 triode (Q103); the collector of the No. 3 triode (Q103) and the collector of the No. 2 triode (Q102) are respectively connected with the grid of the P-MOS (Q104); the emitter of the No. 1 triode (Q101), the emitter of the No. 2 triode (Q102) and the emitter of the No. 3 triode (Q103) are grounded. The emitter of the No. 1 triode (Q101), the emitter of the No. 2 triode (Q102) and the emitter of the No. 3 triode (Q103) are mutually connected and are connected with the No. 5 resistor (R105) to be grounded; no. 3 resistance (R103) is connected between No. 1 triode (Q101), No. 3 triode (Q103), connects No. 4 resistance (R104) between No. 3 triode (Q103), P-MOS (Q104), connects No. 2 resistance (R102) between zener diode (D101) and external voltage DET _ EN. The detected voltage of the Zener diode (D101) is 8.2V, which can be adjusted according to the actual situation

The power supply circuit is connected with the voltage abnormality detection control circuit, the source of a P-MOS (Q104), a resistor (R103) No. 3 and a resistor (R104) No. 4 are connected with the power supply circuit, and the drain of the P-MOS (Q104) and the other end of the resistor (R105) No. 5 are connected with a detection signal.

The working principle of the circuit is as follows:

during normal operation, DET _ OUT is at a high level, during 12V power-down, DET _ OUT is at a low level, and during standby (12V power-down as well), DET _ OUT is at a high level.

1. In normal operation

12V starts first, DET _ EN pulls high later, Q102 is in an open state in advance, so that the base of Q104 is at a low level, the S/D of Q104 is in an on state, and DET _ OUT is at a high level.

2. When an abnormality occurs

When 12V drops below 8.2V, Q102 is turned off, Q104 is high in base level, Q104 is not turned on, DET _ OUT is low in base level

3. When the television is in standby

DET _ EN is actively pulled low first, turning off the detection circuit. At this time, Q103 is in an on state and Q104 is locked in an on state. When the 12V standby is changed to 7V, the state of Q102 does not affect the state of Q104, and thus DET _ OUT remains at a high level without malfunction.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the utility model. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A voltage abnormality detection control circuit is characterized in that: the device comprises a triode No. 1 (Q101), a triode No. 2 (Q102), a triode No. 3 (Q103), a P-MOS (Q104) and a Zener diode (D101); the base electrode of the No. 1 triode (Q101) is connected with the circuit enabling DET _ EN, and the emitter electrode of the No. 2 triode (Q102) is connected with the monitoring voltage 12V through the Zener diode (D101); the collector of the No. 1 triode (Q101) is connected with the base of the No. 3 triode (Q103); the collector of the No. 3 triode (Q103) and the collector of the No. 2 triode (Q102) are respectively connected with the grid of the P-MOS (Q104); the emitter of the No. 1 triode (Q101), the emitter of the No. 2 triode (Q102) and the emitter of the No. 3 triode (Q103) are grounded.

2. The voltage abnormality detection control circuit according to claim 1, characterized in that: the emitter of the No. 1 triode (Q101), the emitter of the No. 2 triode (Q102) and the emitter of the No. 3 triode (Q103) are mutually connected and are connected with the No. 5 resistor (R105) to be grounded; no. 3 resistance (R103) is connected between No. 1 triode (Q101), No. 3 triode (Q103), connects No. 4 resistance (R104) between No. 3 triode (Q103), P-MOS (Q104), connects No. 2 resistance (R102) between zener diode (D101) and external voltage DET _ EN.

3. The voltage abnormality detection control circuit according to claim 1, characterized in that: the detected voltage of the zener diode (D101) is 8.2V.

4. A voltage anomaly detection power supply for an LED display is characterized in that: the voltage abnormality detection control circuit according to any one of claims 1 to 3 is connected to the power supply circuit, the source of the P-MOS (Q104), the resistor No. 3 (R103), and the resistor No. 4 (R104) are connected to the power supply circuit, and the drain of the P-MOS (Q104), and the other end of the resistor No. 5 (R105) are connected to the detection signal.