JPS5840693Y2 - Television receiver power switch control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power switch control device for a television receiver.

Conventionally, a stepping relay is used for the sub power switch operated by the remote controller, so if the main power switch is turned off with the sub power switch turned off by the remote controller, the next time the main power switch is turned on, the The main power circuit did not work, and the user had to operate a reset switch or remote controller to turn on the sub-power switch, making the operation complicated and making it difficult to display images quickly.

Also, if you forget or do not know that the sub power switch is turned off by the reset switch or remote controller, you may mistakenly think that it is not a malfunction because no image appears even if you turn on the main power switch. It was causing inconvenience.

FIG. 1 shows a specific example of the circuit, in which 1 is a remote control oscillator, 2 is a light emitting diode, 3 is a photodiode, 4 is a remote control light receiving section with a built-in preamplifier, 5 is a main amplifier of the remote control receiving section 18, and 6 is a remote control receiving section 18. A frequency detector that detects a scanning command from the bottom to the top of the channel, 7 a frequency detector that detects a scanning command from the top to the bottom of the channel, 8 a frequency detector that detects a command to the power supply/volume, 9- 11 is a switch, 12 is a channel selection section, 13 is a sub-power switch consisting of a stepping relay connected between the switch 11 and the power supply circuit 14 of the remote control receiving section, 15 is a reset switch for turning on the sub-type switch 13, 16 is a main power switch for the main power circuit 17;

In order to solve this problem, the present invention automatically turns on the sub-power switch operated by the reset switch or remote controller by turning off the main power switch of the television receiver, and then the main power switch is turned on. The purpose is to display an image as soon as it is turned on.

An embodiment of the present invention will be described below based on the drawings.

Components that operate in the same way as in FIG. 1 are designated by the same reference numerals. The collector and emitter of a transistor TR1 are connected to both ends of a reset switch 25 for generating a signal that changes the state of the stepping relay Ly constituting the sub power switch 13, and a bias current is supplied from the collector to the base via a resistor R2. A resistor R1 is connected between the base and ground to stabilize the switching operation of the transistor TR1, and the emitter is grounded via a resistor R3.

This reset switch 25 and transistor TR1 constitute a reset signal generation circuit.

On the other hand, the AC voltage stepped down via the transformer 26 connected between the main power switch 16 and the sub power switch 13 provided on the AC line is converted into DC by the diode D3 and the capacitor C1, and the DC voltage is used for backflow prevention. Diode D
1 through the transistor T of the reset switch 25
Add it to one end of R1 on the side connected to the emitter.

Furthermore, the DC output voltage of the main power circuit 17, which operates only when the main and sub-side power switches 16 and 13 are turned on and supplies DC voltage to each main circuit of the television receiver, is connected to the resistor R4 for backflow prevention. Similarly, it is applied to the one end of the reset switch 25 through the diode D2.

Also, connect the intersection of diode D2 and resistor R4 to capacitor C.
2, so that a predetermined DC voltage is maintained for a certain period of time even if the main power supply circuit 17 stops operating.

The capacitance value of the capacitor C1 is such that its discharge time is such that the voltage stepped down from the transformer 26 is supplied and rectified to obtain a DC power source for driving each circuit of the stepping relay Ly and the remote control receiver. The discharge time of the capacitor C2 is set to be shorter than the discharge time of the rectifying capacitor C3 of the remote control receiver power supply circuit 14, and the discharge time of the capacitor C2 is longer than the discharge time of the capacitor C3.

In the circuit configured as described above, if the sub power switch 13 is now turned off by remote control, the operation of the main power circuit 17 has stopped, so the capacitor C2 is not charged.

However, capacitors C1 and C3 are fully charged.

Next, immediately after the main power switch 16 is turned off, since the capacitance of the capacitor C1 is small, discharging is completed quickly, and the emitter potential of the transistor TR1 drops, but since the capacitance of the capacitor C3 is large, it is slowly discharged.

Therefore, a DC voltage remains at the collector and base of the transistor TR1, making the transistor TR1 conductive, and the same potential change as when the reset switch 25 is turned on occurs, so the stepping relay Ly operates, and the sub power switch 13 is turned on. to hold.

On the other hand, if the main power switch 16 is turned off while the sub power switch 13 is in the on state, the emitter of the transistor TR1 The potential does not fall and is in a cut-off state, and the sub power switch 13
remains on and does not move.

In this way, when the main power switch 16 is turned off, the sub power switch 13 is always turned on, and this state is maintained because of the stepping relay Ly.
Next, the main power switch 16 is turned on and at the same time a television image is obtained.

According to the present invention, even if the main power switch is turned off while the sub power switch remains off, the sub power switch is automatically turned on immediately after, and then the main power switch is turned on. You will always get a television image,
This eliminates the inconvenience of the conventional system where the sub power switch is turned off, resulting in no images being displayed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional example, and FIG. 2 is a circuit diagram showing an embodiment of the present invention. 13... Sub power switch, 14... Remote control receiver power circuit, 16... Main power switch, 17... Main power circuit, 25... ...Reset switch, Ly...Stepping relay, C1-C3...Conductor.

Claims (1)

[Scope of utility model registration request] The auxiliary power switch installed in series with the main power switch installed on the AC power line is configured with a stepping relay, and the DC power supply that drives each circuit of the remote controller receiver and the stepping relay is located between the main and auxiliary power switches. A first rectifier circuit and a second rectifier circuit with a short time constant are provided, and a part of the output line of the DC voltage obtained from the main power circuit that operates when both the main and sub power switches are turned on has a short time constant. A long third circuit is added, and the second rectifier circuit and the third circuit are connected to the reset signal generation circuit via diodes that prevent reverse current flow, and the third circuit, the first rectifier circuit, and the second 1. A power switch control device for a television receiver, characterized in that the circuit time constant is set to become shorter in the order of the rectifier circuits.