JP2000125468A - Power supply device for electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power consumption in a waiting state. SOLUTION: This power supply device of an electronic apparatus has a transformer 10, which has a primary winding N1 with a changeover tap TC and secondary windings N2a and N2b and a changeover control means, which changes the number of turns of the primary winding N1 of the transformer 10 to control the voltages induced in the secondary windings N2a and N2b. The voltages induced in the secondary windings of the transformer 10 are used for the operations of the electronic apparatus and the changeover conter means. The changeover control means controls the input voltage, so as to have it applied to the winding between both the terminals of the primary winding N1 in the waiting state of the electronic apparatus and so as to have it applied to the winding between one of the terminal and the changeover tap TC of the primary winding N1, when the operation of the electronic circuit is started and the electronic apparatus is driven by the voltage induced in the secondary winding of the transformer. With this constitution, the voltage induced in the secondary winding in the waiting state of the electronic apparatus becomes lower than the voltage induced in the operation state of the electronic apparatus, so that power consumption in the waiting state can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply for electronic equipment. In detail, using a transformer having a primary winding and a secondary winding having a switching tap capable of switching the number of windings of the winding, a standby state of the electronic device is applied to a winding between both terminals of the primary winding. , The application of the input voltage,
During operation of the electronic device, the voltage induced in the secondary winding is controlled by applying an input voltage to the winding between one terminal of the primary winding and the switching tap, and the induced voltage is induced in the secondary winding. By operating the electronic device using a voltage,
This is to reduce the power consumption of the electronic device during standby.

[0002]

2. Description of the Related Art In recent years, various countermeasures have been taken against environmental problems. For example, in electronic equipment, power consumption during operation has been reduced in order to reduce power consumption most effectively. Have been done. Since the amount of generated power can be reduced by reducing the power consumption in this manner, the amount of carbon dioxide generated due to power generation can be reduced.

[0003]

By the way, electronic equipment consumes power not only during operation but also during standby. For example, by supplying power to a remote control signal receiving circuit (hereinafter referred to as “remote control receiving circuit”),
When the remote control receiving circuit detects that a predetermined signal has been supplied from a remote control signal transmitter (hereinafter referred to as “remote control transmitter”), the operation of the electronic device is started immediately. Therefore, in order to further reduce the power consumption of the electronic device, it is necessary to reduce not only the power consumption during operation but also the power consumption during standby.

In view of the foregoing, an object of the present invention is to provide a power supply device for an electronic device capable of reducing power consumption of the electronic device during standby.

[0005]

A power supply device for an electronic device according to the present invention includes a transformer having a primary winding having a switching tap and a secondary winding, and a primary winding of the transformer which is switched in number. Switching control means for controlling a voltage induced in the secondary winding, wherein the operation of the electronic device and the switching control means is performed using the voltage induced in the secondary winding of the transformer; In the electronic device, control is performed such that an input voltage is applied to a winding between both terminals of a primary winding when the electronic device is on standby. Next, in order to start the operation of the electronic device, for example, when the switching control unit detects that an operation switch, a remote control device, or the like has been operated,
For the winding between one terminal of the primary winding and the switching tap,
Control is performed so that an input voltage is applied.

The transformer has first and second secondary windings, and supplies a voltage induced in the first secondary winding to electronic equipment. The induced voltage is supplied to the switching control means.
In the power supply to the electronic device on the secondary winding side, power supply adjusting means is provided. In the power supply adjusting means, the induced voltage value of the first secondary winding is determined by the power supply adjusting means. If the voltage is within the predetermined voltage range, the operation is performed to stop supplying power to the electronic device.

Further, a switching tap is provided in the second secondary winding of the transformer, and the number of turns of the secondary winding is switched by the switching control means to control an induced voltage of the secondary winding, thereby obtaining an electronic control. When the electronic device is on standby, the second secondary winding of the transformer is supplied with the voltage induced in the winding between one terminal of the second secondary winding of the transformer and the switching tap to the switching control means. Control is performed so that a voltage induced in the winding between both terminals of the next winding is supplied to the switching control means.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of a power supply device for an electronic device according to the present invention. The transformer 10 has a primary winding N1 and two secondary windings N2a (number of windings K2a), N2b (number of windings K2b).
have. On the primary winding N1 side, the winding
1a (number of windings K1a) and winding N1b (number of windings K1
A switching tap TC is provided at a position divided into b).
One terminal T1 of the primary winding N1 of the transformer 10 is connected to one terminal of the AC plug 11 and the primary winding N
The other terminal T2 is connected to a contact terminal R1b of the switching circuit of the relay 13. The other contact terminal R1 of the relay 13
a is connected to the switching tap TC of the primary winding N1 of the transformer 10. The contact common terminal R1c of the relay 13
It is connected to the other terminal of the plug 11. Commercial power is supplied to the AC plug 11. The terminals Tb1 and Tb2 of the secondary winding N2b are connected to the AC input terminals 20a and 20b of the bridge rectifier circuit 20. Terminals Ta1 and Ta2 of another secondary winding N2a are connected to a load (not shown) of the electronic device. The positive output terminal 20c of the bridge rectifier circuit 20 is connected to the input terminal side of the constant voltage circuit 30, and the negative output terminal 20d is grounded. Also,
A smoothing capacitor 25 is connected between the positive output terminal 20c and the negative output terminal 20d of the bridge rectifier circuit 20. The output terminal side of the constant voltage circuit 30 is connected to the control unit 40 constituting the switching control means and one terminal L1 of the coil of the relay 13. The other terminal L2 of the coil is connected to the collector of the transistor 50 constituting the switching control means. The emitter of the transistor 50 is grounded, and the base is connected to the control unit 40. The control unit 40 includes an operation switch 41 for operating an electronic device and a remote control receiving circuit 42 for receiving a signal from a remote control transmitter.
Is connected.

In this power supply device, the operation switch 41
Is operated, or when the operation of the electronic device in the standby state is started based on the reception signal from the remote control reception circuit 42, the transistor 50 is turned on by the control signal CTP from the control unit 40. . At this time,
A current flows through the coil of the relay 13 and the terminals of the relay 13 are electrically connected to the terminals R1a and R1c. Therefore, the input voltage supplied from the AC plug 11 is applied to the terminal T1 of the primary winding N1 and the switching tap TC. Input voltage is Vin
Assuming that the voltage induced in the secondary winding N2a at this time is Vop, Vop = Vin × (K2a / K1a)
Can be represented by

Next, when the electronic device is set in the standby state, the transistor 50 is turned off based on the control signal CTP from the control unit 40. Therefore, no current flows through the coil of the relay 13, and the contact of the relay 13 is connected to the terminal R1.
b and R1c conduct. For this reason, the input voltage supplied from the AC plug 11 is applied to the terminals T1 and T2 of the primary winding N1, and the voltage induced in the secondary winding N2b is
The DC voltage is converted to a DC voltage Vd by the bridge rectifier circuit 20. The DC voltage Vd is converted to a predetermined voltage Vs by the constant voltage circuit 30.
The operation of the control unit 40 is performed using the predetermined voltage Vs. The predetermined voltage Vs is also supplied to the relay 13. Here, the voltage induced in the secondary winding N2a is Vst
Then, Vst = Vin × (K2a / (K1a + K1)
b)). Therefore, the voltage induced during standby and supplied to the load of the electronic device is lower than the voltage during operation due to the larger number of primary windings.

According to the above-described embodiment, the input voltage is applied to the winding between the two terminals of the primary winding of the transformer when the electronic device is on standby, and is connected between one terminal of the primary winding and the switching tap during operation. Is applied to the windings. Therefore, the voltage induced in the secondary winding of the transformer during standby of the electronic device is lower than the voltage during operation.

As described above, the power supply device of the first embodiment controls the voltage induced in the secondary winding by switching the number of windings of the primary winding of the transformer. Supplying a desired voltage to a load of an electronic device and reducing power consumption during standby by supplying a lower voltage than during operation when the electronic device is not required to operate. Can be.

FIG. 2 shows a second embodiment of the present invention. The power supply device of FIG. 2 is obtained by adding a power supply adjustment unit that adjusts the supply of power to the load of the electronic device to the first embodiment described above. 2, the same reference numerals are given to the portions corresponding to FIG. 1, and the detailed description is omitted.

The power supply adjusting means is constituted by using Zener diodes 60 and 61. The terminal Ta1 of the secondary winding N2a of the transformer 10 is connected to the cathode of the Zener diode 60, and the anode of the Zener diode 60 is connected to the next Zener diode. The anode of the diode 61 is connected, and the cathode of the Zener diode 61 is connected to a load (not shown) of the electronic device.

Here, the Zener voltage value of the Zener diodes 60 and 61 is lower than the voltage value induced in the secondary winding N2a during operation of the electronic device and higher than the voltage value induced during standby of the electronic device. Selected. Therefore, the voltage induced in the secondary winding N2a during standby of the electronic device is lower than the Zener voltage value of the Zener diodes 60 and 61, so that power is not supplied to the load. In the operation of the electronic device, the voltage induced in the secondary winding N2a is a voltage at which the load of the electronic device can operate normally, and this voltage is higher than the Zener voltage value of the Zener diodes 60 and 61. The required power is supplied to the load.

According to the above-described operation, the power supply device of the second embodiment adds the power supply adjusting means to the first embodiment, so that the power supply device can supply the electric power at the standby time when the operation of the electronic device is not required. Can be stopped. Therefore, power consumption during standby can be further reduced as compared with the first embodiment.

FIG. 3 shows an embodiment of a third power supply unit according to the present invention. The power supply device shown in FIG.
In the third embodiment, the number of turns of the secondary winding is switched to control the voltage supplied to the switching control means connected to the secondary winding. Note that, in FIG. 3, the portions corresponding to those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 3, the secondary winding N2b of the transformer 10 is connected to a winding N2b1 (the number of windings K2b).
1) A switching tap Tbc is provided at a position where the switching tap Tbc is divided into windings N2b2 (K2b2). The relay 14 has two switching circuits, and the first switching circuit corresponds to the switching circuit of the relay 13 of the first and second embodiments described above,
It is used for controlling the switching of the number of turns of the primary winding N1 of the transformer 10. The second switching circuit is used for switching the number of secondary windings newly added in the third embodiment. Further, the first and second switching circuits are controlled by a current supplied to one coil of the relay 14. In the figure, the contact terminals R1a and R1b of the first switching circuit of the relay 14 are respectively connected to the switching tap TC and the terminal T2 of the primary winding N1 of the transformer 10, and the common terminal R1c of the contact is connected to one terminal of the AC plug. Is done. Similarly, the second switching circuit of the relay 14 is used for switching the number of turns of the secondary winding N2b, and its contact terminals R2a and R2b are connected to the switching tap Tb of the secondary winding N2b.
c and the terminal Tb1, and the common terminal R1
c is connected to the input terminal 20a of the bridge rectifier circuit 20. One terminal L1 of the coil terminal of the relay 14 is connected to the output terminal side of the constant voltage circuit 30, and the other terminal L2 of the coil is connected to a transistor 50 constituting the switching control means.
Connected to the collector.

Here, when the electronic device operates, the control unit 40
The transistor 50 is turned on by the control signal CTP. Since the current flows through the coil of the relay 14 when the transistor 50 is turned on, the contact of the relay 14 is connected to the terminal R1.
a and R1c and the terminals R2a and R2c become conductive. As a result, the input voltage is applied to the terminal T1 of the primary winding N1 and the switching tap TC, and the voltage induced in the switching tap Tbc and the terminal Tb2 is applied to the secondary winding N2b. Is supplied to the control unit 4
0 operation is performed.

On the other hand, when the electronic device is on standby, the transistor 50 is turned off by the control signal CTP from the control unit 40, so that no current flows through the coil of the relay 14. Therefore, the contact of the relay 14 is connected to the terminals R1b and R1b.
1c conducts, and similarly, the terminals R2b and R2c conduct. Therefore, an input voltage is applied to the primary winding N1 between the terminals T1 and T2. In the secondary winding N2b, the terminal Tb
The voltage induced between 1 and Tb2 is supplied to the bridge rectifier circuit 20 connected to the load side, and the operation of the control unit 40 is performed.

By the operation described above, the power supply device of the third embodiment switches the number of windings of the second secondary winding for supplying a voltage to the switching control means to the power supply device of the first embodiment. By adding the means, the voltage induced in the second secondary winding can be adjusted to the required appropriate voltage. Therefore, it is possible to prevent an extra voltage from being supplied to the switching control means connected to the load side. Therefore, the first
Power consumption can be further reduced as compared with the embodiment.

In the above description of the three embodiments, the control for changing the number of windings of the primary and secondary windings is not limited to the case of using a relay, but is performed using, for example, a semiconductor element or the like. Of course, it may be good.

[0023]

According to the present invention, an input voltage is applied to a winding between both terminals of a primary winding of a transformer or a winding between one terminal and a switching tap, and induced in a secondary winding of the transformer. The operation of the electronic device and the application control means is performed using the applied voltage. During operation of the electronic device, a predetermined power desired by the electronic device is supplied by applying an input voltage to the winding selected by the switching tap of the primary winding. Also, when the electronic device is on standby, a lower voltage is supplied to electronic devices that do not need to operate by applying an input voltage to the winding between the two terminals of the primary winding compared to when the device is in operation. Then, the switching control means is operated by supplying necessary power. By providing the means for switching the number of primary windings, power consumption during standby can be reduced with an inexpensive and simple configuration.

Further, the transformer includes first and second secondary windings, and the operation of the electronic device is performed using the voltage induced in the first secondary winding, and the second secondary winding of the transformer is operated. The operation of the switching control means is performed using the voltage induced in the secondary winding. In supplying power to the electronic device on the first secondary winding side, power supply adjusting means is added. With the provision, power supply to an electronic device that does not need to operate during standby can be stopped, so that power consumption during standby can be further reduced.

Further, by providing a means for switching the number of windings to the second secondary winding, a voltage to be supplied to the switching control means can be adjusted to an appropriate voltage. , Power consumption can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of a power supply device of an electronic apparatus of the present application.

FIG. 2 is a diagram illustrating a second embodiment of the power supply device of the electronic apparatus of the present application.

FIG. 3 is a diagram showing a third embodiment of the power supply device of the electronic apparatus of the present application.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Transformer 11 AC plug 13 Relay 20 Bridge rectifier circuit 30 Constant voltage circuit 40 Control part 41 Operation switch 42 Remote control receiving circuit 50 Transistor 60, 61 Zener diode

Claims (3)

[Claims] 1. A transformer having a switching tap on a primary winding, and switching control means for switching a number of windings on a primary winding side and controlling a voltage induced on a secondary winding side using the switching tap. And using a voltage induced on the secondary winding side of the transformer,
The electronic device and the operation of the switching control means shall be performed, and the switching control means shall apply an input voltage between both terminals of the primary winding during standby of the electronic device,
A power supply device for an electronic device, wherein an input voltage is applied between one terminal of the primary winding and the switching tap during operation of the electronic device. 2. The transformer has first and second secondary windings, supplies a voltage induced in the first secondary winding to the electronic device, and supplies the second secondary winding. The voltage induced in the line is supplied to the switching control means. The first secondary winding of the transformer is connected to the electronic device when the induced voltage is within a predetermined voltage range. The power supply device for an electronic device according to claim 1, further comprising a power supply adjusting unit that stops supplying power. 3. The transformer has first and second secondary windings, and supplies a voltage induced in the first secondary winding to the electronic device and the second secondary winding. A voltage induced in the line is supplied to the switching control means. A switching tap is provided in the second secondary winding of the transformer. A voltage induced between both terminals of the secondary winding of the second transformer is supplied to the switching control means, and during operation of the electronic device, a voltage between one terminal of the second secondary winding of the transformer and the switching tap is provided. 2. The power supply device for an electronic device according to claim 1, wherein a voltage induced in said switching device is supplied to said switching control means.