JPH07284225A - Electronic device - Google Patents

Abstract

PURPOSE:To control power consumption in a power supply circuit under the non-operating condition by turning off, with a switch means, the power supplied to the power supply circuit when a power off operating means has detected the off condition. CONSTITUTION:When a power-off key of an operation panel 9 is manipulated, a microcomputer 7 identifies the operation of this power-off key and stops operation of a device 6 to be operated to bring about the power-off condition. Simultaneously, a control signal of level 'L' is outputted from an output port 7a to make non-conductive a transistor 22. As a result, a relay coil 21b is de- energized to open a contact 21a, cutting off the connection of an AC 100V in the input side of a high frequency switching circuit 3 to the commercial power supply. Therefore, supply of the power to the power supply circuit is disconnected perfectly and thereby power consumption in the power supply circuit under the power-off condition can be controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device capable of suppressing power consumption in a power supply circuit when a driven device is turned off by a power off operation.

[0002]

2. Description of the Related Art FIG. 2 is a circuit diagram showing a configuration of a conventional power supply circuit used in, for example, a video tape recorder as an electronic device. In the figure, 1 is AC 100
Plugs 1a and 1b for connecting to the commercial power supply of the bolt
Is an input terminal to the power supply circuit of AC 100V. Two
Is a rectifier circuit for rectifying 100 V AC, and 3 is a high-frequency switching circuit section. Switching is performed by a horizontal cycle signal based on the DC power supply of the rectifier circuit 2, and its high-frequency voltage is supplied to a flyback transformer (high-frequency transformer) 4. Output to the primary coil. Reference numeral 5 denotes a plurality of high-frequency rectifier circuits that rectify the outputs of the plurality of secondary side coils of the flyback transformer 4 that have stepped up and stepped down the high-frequency voltage to generate a DC high voltage and a predetermined DC voltage. , A rectifying diode and a smoothing capacitor.

Reference numeral 6 is a driven device, and in the present embodiment, it is driven with different voltage and power specifications such as a video signal processing unit in a video tape recorder device, a display unit, a motor, a tuner unit and a servo control unit. 2 shows a plurality of driven devices to be driven. 7 is a microcomputer which is a system control unit for controlling the display unit including the video signal processing unit, the motor, the tuner unit and the servo control unit, and 8 is the microcomputer 7 and the video signal processing unit, the display unit, A bus for connecting driven devices such as a motor, a tuner unit, and a servo control unit, and 9 is an operation unit including various operation keys for inputting operation signals to the microcomputer 7. Reference numeral 10 denotes a backup power supply circuit for the microcomputer 7, which includes a backup battery 10a or an electrolytic capacitor.
Reference numeral 11 is a diode for charging the backup battery 10a of the backup power supply circuit 10 so that the power of the backup battery 10a does not flow back to the rectifier circuit 5 side when performing backup. The backup power supply circuit 10 backs up the necessary minimum circuits such as the microcomputer 7 including a storage unit, the key input unit 9 and the timer unit.

Next, the operation will be described. When powering off the driven device 6 connected to the power supply circuit, the power off key of the operation unit 9 is operated to stop the operation of the driven device 6 under the control of the microcomputer 7 (power off operation means). . However, the driven device 6
When the plug 1 is connected to a commercial power supply of AC 100 V, the high frequency switching circuit 3 is in an operating state even when the power supply is stopped. Therefore, the flyback including the high frequency switching circuit 3 is included. Transformer 4,
There is power consumption of the high frequency rectifier circuit 5 and the like.

[0005]

Since the conventional power supply circuit is constructed as described above, the plug 1 is operated even when the driven device is powered off and stopped by the power off operation means.
There is a problem that it is impossible to reduce the power consumption to zero unless the power is removed from the commercial power source of 100 V AC. The power consumption when the driven device is powered off and stopped by the power-off operation means is usually on the order of 20 to 30% of the rated power consumption of the entire device such as the driven device.

The present invention has been made to solve the above problems, and suppresses power consumption in a power supply circuit when a driven device is powered off by a power-off operation means and brought into a stopped state. The purpose is to provide an electronic device capable of performing.

[0007]

The electronic device according to the present invention sends a power-off signal to the electronic device when the power supply circuit of the electronic device turns off the power supplied to the driven circuit. In an electronic device equipped with a power-off operation means for turning off the power supply from the power supply circuit to the drive circuit without turning off the power input line to the power supply circuit, a switch means for opening and closing the input line of the power supply circuit. ,
Power-off detection means for detecting power-off to the power supply circuit and power-off operation means to the driven device, and the power-off detection means for turning off power supply to the power supply circuit or the And a control means for interrupting the power supplied to the power supply circuit by the switch means when it is detected that the drive device is turned off by the power off operation means.

[0008]

In the electronic apparatus according to the present invention, when the power-off detecting means detects that the power supply to the power supply circuit is off or the power-off operation means to the driven device is off, the power supplied to the power supply circuit is switched by the switch means. By cutting off, the power consumption of the power supply circuit when the driven device is powered off and brought into a stopped state is suppressed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a power supply circuit of a video tape recorder device which is an electronic device of this embodiment.
In FIG. 1, parts that are the same as or correspond to those in FIG. 2 are assigned the same reference numerals and explanations thereof are omitted.

In the figure, reference numeral 21 denotes a relay circuit, which has a contact 21a for cutting off the connection to the AC 100-volt commercial power source on the input side of the rectifier circuit 2 and a relay coil 21b for driving the contact 21a. The contact 21a is a normally open contact, and the relay coil 21b is connected to the positive electrode side output terminal of the backup battery 10a of the backup power supply circuit 10. Reference numeral 22 is a transistor for driving the relay coil 21b of the relay circuit 21, 23 is a resistor for limiting the base current of the transistor 22, 7a
Is an output port of the microcomputer 7.

Next, the operation will be described. It is assumed that the battery 10a or the electrolytic capacitor of the backup power supply circuit 10 is charged with sufficient energy to back up the microcomputer 7. First, when the power-on operation is performed by the operation unit 9, the microcomputer 7 outputs a control signal of'H 'level from the output port 7a. As a result, the transistor 22 becomes conductive and the relay coil 21b is excited by using the backup power supply circuit 10 as a power source. Therefore, the contact 21a is closed, the high frequency switching circuit 3 is connected to an AC 100V commercial power source, and DC power is supplied to the driven device 6,
Each part of the driven device 6 operates. After the contact 21a is closed, the relay coil 21b is kept excited by the DC power supplied to the high frequency switching circuit 3 via the diode 11.

When the power off key of the operating section 9 is operated in this state (power off operation means), the microcomputer 7 identifies the operation of this power off key and stops the driven device 6 to bring it into the power off state. At the same time, the control signal of the “L” level is output from the output port 7a to bring the transistor 22 into the non-conducting state. As a result,
The relay coil 21b is deenergized and the contact 21a is opened, cutting off the connection of the input side of the high-frequency switching circuit 3 to a commercial power supply of AC 100 V, and the power consumed by the converter of the high-frequency switching circuit 3 and the like. Suppress. Here, in the backup power supply circuit 10,
When an electrolytic capacitor is used for the power supply, it discharges after a certain period of time, but in this case, the microcomputer 7 of the system control unit detects this when the voltage falls below a predetermined voltage and automatically turns off the power normally. The operation is started, the electrolytic capacitor is charged, and when the charging is completed, the power cut operation is started again.

As described above, in the present embodiment, the driven device 6
When the power is turned off, the contact 21a is opened accordingly, and the AC 100 on the input side of the high frequency switching circuit 3 is
Since the connection of the volt to the commercial power supply is cut off, the power supply to the power supply circuit is completely cut off, and the power consumption in the power supply circuit in the power off state is suppressed.

In the embodiment described above, the relay circuit 21 is used to cut off the connection of the input side of the high frequency switching circuit 3 to the commercial power source of 100 VAC, but the contact 21a of the relay circuit 21 is used. A photo triac and a light emitting diode may be used instead of the relay coil 21b, and the photo triac and the light emitting diode may be controlled by the microcomputer 7. With such a configuration, it is possible to use the backup power supply circuit 10 having a smaller capacity than the case where the relay circuit 21 is used.

[0015]

As described above, according to the present invention, when the driven device of the electronic device is stopped by the power-off operation means, the power-off detection means detects it, and the switch means supplies the power circuit. Since the input side of is turned off, there is an effect that power consumption in the power supply circuit can be suppressed.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a configuration of a power supply circuit of a video tape recorder device which is an electronic device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a configuration of a power supply circuit of a conventional video tape recorder device.

[Explanation of symbols]

3 High Frequency Switching Circuit 6 Driven Device 7 Microcomputer (Power Off Detection Means, Control Means) 10 Power Supply Circuit for Backup 21 Relay Circuit (Switch Means)

Claims (1)

[Claims] 1. When turning off the power supplied from a power supply circuit of an electronic device to its driven circuit, a power-off signal is sent to the electronic device so that the power input line to the power supply circuit is not turned off. In an electronic device equipped with a power-off operation means for turning off power supply from the power supply circuit to the drive circuit, a switch means for opening and closing an input line of the power supply circuit, turning off power supply to the power supply circuit, and Power-off detecting means for detecting whether the driven device is turned off by the power-off operating means, and the power-off detecting means turning off power supply to a power supply circuit or turning off the driven device by the power-off operating means. And a control unit that cuts off the power supplied to the power supply circuit when the switch is detected.