JPS61255420A - Signal discriminating power source automatic stopping circuit - Google Patents

Abstract

PURPOSE:To reduce average power consumption by controlling on/off of power source of a display device automatically utilizing presence of signals outputted always at an interval when an electronic apparatus that sends out video signals is in operation. CONSTITUTION:While video signals are being sent at a time interval, a one shot multivibrator 4 is reset every time. Accordingly, output B continues to keep the state of low level, and a part between the emitter terminal 2 and collector terminal 3 of an NPN switching transistor becomes the state of conduction, and electric power is supplied to a load connected to the terminal 3. On the other hand, when video signals ceased for more than a specified time, the one shot multivibrator 4 is not reset, and output B becomes high level. Consequently, the NPN switching transistor becomes cut off state, and electric power is not supplied to the load connected to the terminal 3. Thus, consumption of futile electric power can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a circuit for turning on and off the power of an electronic display device that is separate from an electronic device that outputs a video signal.

[Prior art]

Conventional electronic display devices that visually express video signals and electronic devices that output video signals exist separately, except for the display device that receives power from the electronic device. However, the disadvantage is that the display device operates, shortening its lifespan and increasing average power consumption.

〔the purpose〕

The present invention solves these drawbacks, and its purpose is to:
The purpose is to shorten the operating time of electronic display devices and extend their lifespan. Another object of the invention is to reduce the average power consumption of electronic display devices.

〔overview〕

The present invention detects the presence or absence of a signal that is output at certain intervals whenever an electronic device that transmits a video signal is in operation, and automatically turns on and off the power of the display device based on this.

〔Example〕

FIG. 1 shows an example of a circuit according to the present invention, in which 1 is a video signal input terminal, 2 is a power input terminal, and 3 is a power output terminal, which is connected to, for example, a drive circuit of a display device (not shown).

4 is a retriggerable one-shot multipipulator that detects the presence or absence of a video signal. While the video signal is being sent at certain intervals, the output of the multivibrator is 'L' and the transistor is 'ON'.

If the video signal is interrupted for more than a certain interval, the multivibrator output will be “H”C and the transistor will be turned OFF.
``In this state, the current flowing to the stain source output terminal is interrupted and the circuit connected thereto ceases its operation.

〔effect〕

As explained above, there is an advantage that the presence or absence of a video signal is linked to the power supply of the circuit system of the display device, and the power supply of the electronic device that outputs the video signal and the power supply of the display device can be operated at the same time.

[Brief explanation of drawings]

FIG. 1 shows an example of the circuit of the present invention (S#), and FIG. 2 is its timing chart. 1...Video signal input terminal 2...Power input terminal 3...Power output terminal 4...Retriggerable one-shot multivibrator or above

Claims (1)

[Claims] A signal discrimination power supply characterized by having a circuit that detects the presence or absence of an input signal, determines the operating state of a device that is sending out the input signal, and automatically turns on and off the power of the device. Automatic stop circuit.