Television power supply protective circuit

Abstract

The invention provides a technical proposal of a TV power protection circuit, which comprises a power input voltage Vac transmitted to a first diode D1 and rectified thereby, a filter capacitor C1 for filtering the power input voltage, and a power first chip N1 and a power second chip N2. The proposal is characterized in that an input detection control circuit is serially connected between the negative terminal of the first diode D1 and the power first chip N1, the input detection control shares a power supply voltage Vin with the power first chip N1 and outputs a power supply voltage Vcc under the control of the power first chip N1, the power second chip N2 is supplied with the power supply voltage Vcc and outputs a feedback voltage Vpfc through a control power circuit, the power second chip N2 is connected with a feedback detection circuit, and the feedback detection circuit is connected with the input detection control circuit and the feedback voltage Vpfc.

Description

Technical field: [0001] The invention relates to a protection circuit for a television, in particular to a protection circuit for a television power supply. Background technique: [0002] In the prior art, the well-known technology is Patent No. 97214321.1 authorized by the State Intellectual Property Office, which discloses a TV power protector, which can prevent the TV from burning out when a short circuit occurs in the TV circuit. and the occurrence of fire. The under-voltage and over-voltage protection circuit of the LCD TV power supply has not been found so far. Since the LCD TV power supply has no under-voltage and over-voltage protection, when the input voltage is reduced, the operating current must be increased to ensure the output power, which is extremely difficult. It is easy to burn the front-end devices of the circuit, and when the AC power is cut off, the power management chip is still working for a certain period of time, causing the LCD screen power supply v...

AI Technical Summary

Problems solved by technology

The under-voltage and over-voltage protection circuit of the LCD TV power supply has not been found so far. Since the LCD TV power supply has no under-voltage and over-voltage protection, when the input voltage is reduced, the operating current must be increased to ensure the output power, which is extremely difficult. It is easy to burn the front-end devices of the circuit, and when the AC power is cut off, the power management chip is still working for a certain period of time, causing the power supply voltage of the LCD screen to rebound, causing the LCD screen to appear flickering

When there is a problem with the feedback circuit, the output voltage of the feedback will exceed its set value, which may cause the back-end part to fail to work or be damaged, which is the deficiency of the existing technology

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