JPH0352040Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a switching circuit for an external device connection outlet that switches the power supply to the outlet in an electronic device having a timer CPU and an external device connection outlet. It is something.

(b) Conventional technology Conventionally, as a technology for electronic equipment having a timer CPU and an outlet for connecting external devices, for example, page 30 of "Television Technology June 1984" (published by Denshi Gijutsu Publishing Co., Ltd.) was presented. has been done. To explain the technology below, there are two outlets on the rear panel of an electronic device (VTR).
One is not linked to the VTR power supply, the other is VTR
The power supply can be switched between interlocking and non-interlocking using a changeover switch. If you connect an external device (audio device) to the latter outlet and switch the outlet to the linked side, it will be linked to the VTR's built-in timer CPU or the VTR's power on/off by the user. hand,
The power of the audio equipment could also be turned on/off, that is, it could be used as an audio-visual system.

(c) Problems that the invention aims to solve However, in the above case, if an external device is connected to the latter outlet, the timer CPU will not be able to turn on/off the power of only the external device independently, and the device will no longer be used. Even if the user only intends to use the external device, the electronic device itself must always be powered on, resulting in an increase in power consumption.

(d) Means for solving the problem The present invention was made to solve the above problem, and includes a timer CPU that outputs a control signal at a set time, and a timer CPU for connecting an external device connected to a power supply line. In electronic devices that have an outlet,
a first power supply circuit that is always turned on by power input; a timer CPU that has first and second control terminals and is driven by the output of the first power supply circuit; and an output of the first power supply circuit and a first control terminal. a second power supply circuit that is turned on by a control signal output from the second power supply circuit; a driven section that is driven by the output of the second power supply circuit;
a three-terminal changeover switch connected to the first power supply circuit, the second power supply circuit, and a second control terminal; an output of the first power supply circuit; and an output of the three-terminal changeover switch that is switched to any terminal; This is a switching circuit for an external device connection outlet, which is comprised of a switch circuit that turns on a switching element connected in series with the outlet to bring the outlet into a power supply state.

(E) Effect According to the switching circuit of the external device connection outlet of the present invention, the second control terminal provided on the timer CPU is connected to one terminal of the 3-terminal changeover switch, and the 3-terminal changeover switch is connected to the second control terminal provided in the timer CPU. is switched to the first terminal, the output of the first power supply circuit,
The switch circuit is turned on by the control output from the second control terminal, and the outlet is thereby brought into a power supply state regardless of whether the second power supply circuit is on or off.

(f) Examples The details of the present invention will be explained in detail with reference to illustrated examples.

The drawing is a circuit diagram showing the switching circuit of the outlet for connecting an external device according to the present invention. To explain the figure number and structure of the drawing, 1 is a power plug inserted into a power outlet (not shown), 2 is the power plug. 1 is connected to an AC line; 3 is a first power supply circuit that is connected to the AC line 2 and is always turned on by AC input to convert AC to DC; 4 is a first power supply circuit;
and a timer CPU having second control terminals 5 and 6 and driven by the DC output of the first power supply circuit 3;
8 is a second power supply circuit that is turned on by the output of the first power supply circuit 3 and a control signal output from the first control terminal 5; 9 is a driven section that is driven by the DC output of the second power supply circuit 8; 10; are the first and second
A three-terminal changeover switch 14 has terminals 11, 12, and 13 connected to the power supply circuits 3, 8, and the second control terminal 6.
A transistor 17 is connected to the terminal changeover switch 10, has its collector connected to the first power supply circuit 3 via the relay coil 16, and has its emitter grounded, and is connected between the base of the transistor 14 and the ground. A resistor 18 is connected to both ends of the relay coil 16, and a diode 19 protects the components by consuming back electromotive force generated in the relay coil 16 for some reason.
Reference numeral 20 denotes an outlet for connecting an external device connected in series between the AC line 2 and the relay coil 1.
This is a relay switch as an opening/closing element that is turned on by 6. The switch circuit is composed of the transistor 14, the relay coil 16, the diode 18, and the relay switch 20.

The operation of the drawings will be explained below using a VTR as an example.
First, when the power plug 1 is inserted into a power outlet, the first power supply circuit 3 is always on due to the AC input, and the timer CPU 4 is driven by the DC output of the first power supply circuit 3. Outlet 19 here
It is assumed that an audio device (not shown) is connected in advance as an external device.

When the three-terminal changeover switch 10 is initially switched to the terminal 11, the DC output of the first power supply circuit 3 is input to its base via the resistors 15 and 17, and is also input to its collector via the relay coil 16. is also input, and the transistor 14 is turned on when its rising voltage is exceeded. As a result, an electromotive force is generated in the relay coil 16, and the relay switch 20 is turned on. That is, the outlet 19 is independent of the second power supply circuit 8, and is brought into an AC supply state only by turning on the first power supply circuit 3. In other words, the audio equipment is turned on/off by the power supply alone.

Next, when the three-terminal changeover switch 10 is switched to the terminal 12, when the second power supply circuit 8 is turned on by the control signal output from the first control terminal 5 at the set time or by the user's operation, the The drive section 9 is driven by the DC output of the second power supply circuit 8. Furthermore, the second
The DC output of the power supply circuit 8 is input to its base via the resistors 15 and 17, and the first power supply circuit 3
The DC output of the transistor 14 is inputted to its collector via the relay coil 16, and the transistor 14 is turned on when its rising voltage is exceeded. Therefore, the relay switch 20 is also turned on. That is, the outlet 19 is linked with the second power supply circuit 8, and when the second power supply circuit 8 is turned on, the AC supply state is established.In other words, the VTR
and audio equipment are turned on and off in conjunction,
Various modes using both are possible.

Next, when the three-terminal changeover switch 10 is switched to the terminal 13, when a control signal is output from the second control terminal 6 at the set time, the control output of the second control terminal 6 is transferred to the terminal 13 via the resistors 15 and 17. At the same time, the DC output of the first power supply circuit 3 is input to the collector of the first power supply circuit 3 via the relay coil 16, and the transistor 14 is turned on when the voltage becomes higher than its rising voltage. Therefore, the relay switch 20 is also turned on.
That is, the outlet 19 is independent of the second power supply circuit 8, and is brought into the AC supply state by the control signal output from the second control terminal 6. In other words, the power outlet 19 is supplied with alternating current by the control signal output from the second control terminal 6.
The audio equipment is turned on/off by the control output of CPU4.
It will be turned off. Incidentally, at this time, it is also possible to output control signals from the first and second control terminals 5 and 6 at the same time.

(g) Effects of the invention According to the switching circuit for the external device connection outlet of the invention, the control output of the timer CPU can drive only the external device without driving the electronic device itself, which reduces power consumption. In addition, since the three-terminal changeover switch is provided, only one outlet is required, and there are advantages such as increased flexibility in the installation location of the outlet with respect to the main body of the electronic device.

[Brief explanation of the drawing]

The drawing is a circuit diagram showing a switching circuit of an external device connection outlet according to the present invention. Explanation of main drawing numbers, 2... AC line, 3... 1st power supply circuit, 4... Timer CPU, 5... 1st
Control terminal, 6... Second control terminal, 8... Second power supply circuit, 9... Driven part, 10... 3-terminal changeover switch, 14... Transistor, 16... Relay coil, 18... Diode, 19...Outlet, 20...Relay switch.

Claims (1)

[Scope of utility model registration request] A timer CPU that outputs a control signal at a set time,
and an electronic device having an outlet for connecting an external device connected to a power supply line, which has a first power supply circuit that is always turned on by power input, and first and second control terminals, and is driven by the output of the first power supply circuit. a second power supply circuit that is turned on by the output of the first power supply circuit and a control signal output from the first control terminal; a driven part that is driven by the output of the second power supply circuit; A three-terminal changeover switch connected to a first power supply circuit, a second power supply circuit, and a second control terminal, and the output of the first power supply circuit and the output of the three-terminal changeover switch that is switched to any terminal. A switching circuit for an external device connection outlet, comprising a switch circuit that turns on a switching element connected in series with the outlet to bring the outlet into a power supply state.