JPH0157531B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drive circuit for a load equipped with a control signal generator for a watch or the like, and particularly relates to a load drive circuit that drives only one of a plurality of loads with a control signal generated from a watch or the like. .

Generally, in electronic equipment such as a television receiver with a radio equipped with a clock, a method is often adopted in which a control signal from the clock drives the low frequency circuit of the electronic equipment, such as a radio. Conventionally, a configuration in which only the low frequency circuit of the radio was driven by control signals from the clock in a television receiver with a built-in clock required many switches.

SUMMARY OF THE INVENTION The present invention therefore relates to a novel load drive circuit that eliminates the above drawbacks and enables a load such as an alarm device to operate when the main body of an electronic device such as a television receiver is turned off.

The present invention will be described below with reference to the drawings. 1 is a first DC power supply, 2 and 2' are power switches, and 3 is a first DC power supply.
4 is a second load, 5 is a control signal generator that generates a control signal such as a clock circuit, 6 is a diode as a switching element, 7 is a switching transistor as a switching means, 8 is a coupling capacitor, 9 is a control signal Terminal 10 indicates a second DC power supply.

Next, to explain the operation of the present invention, A and A', B and B', and C and C' of the power switches 2 and 2' are respectively in the inoperative state, that is, the OFF position, the operating state, that is, the ON position, and the control signal generation. First, when the power switch 2, 2' is in the OFF position, that is, the power switch 2, 2' is in the A-A' position, the clock provided as the control signal generator 5 is supplied with power from the second DC power supply. The first load and the second load 4 are powered off. Therefore, the control signal generator 5 performs a timing operation.

When the power switches 2, 2' are switched to the on position, that is, the power switches 2, 2' are switched to B-B', the first load 3
The second load 4 is supplied with power by the first DC power supply 1 and becomes operational. At this time, diode 6 is on, while switching transistor 7 is off. A clock provided as a control signal generator 5 is supplied with power from a second DC power supply 10.

Next, turn the power switches 2 and 2' to the auto position, that is, C.
-C', when the first load 3 is not applied to the control signal 9, the switching transistor 7 is in the off state, and the first load 3 and the second load 4
is kept off. Control signal to control signal terminal 9
When Vc is applied, the switching transistor 7 is turned on for the pulse period by the control signal Vc and turned off for the rest of the time (as an example, a duty of several tenths of a second), and the first load 3 is in the operating state for the pulse period. , the first load 3 is controlled by the control signal Vc through the coupling capacitor 8.

As an example, in the case of a television receiver with a radio, the first load 3 is a low frequency amplification circuit, and the second load 4 is a circuit other than the low frequency amplification circuit, that is, a horizontal deflection circuit, a vertical deflection circuit, etc. which are the television receiver circuit. If provided, as described above, when a control signal (for example, an alarm signal) from the control signal generator 5 is applied to the control signal terminal 9, the first load 3 will reproduce an intermittent sound due to the control signal. Appears as an alarm function.

As described above, according to the present invention, a simple configuration is sufficient when only a specific load of a device equipped with a plurality of loads is driven by a control signal from the control signal generator, and in particular, a clock and a television receiver with a radio. The present invention is highly effective.

[Brief explanation of drawings]

The drawing shows a load driving circuit of the invention. Explanation of main drawing numbers, 1...1st DC power supply, 2, 2'
...power switch, 3...first load, 4...second load,
5... Control signal generator, 6... Switching diode, 7... Switching transistor, 10... Second
DC power supply.

Claims (1)

[Claims] 1. A DC power source having first and second electrodes, and first and second power sources each having a movable terminal connected to the first and second electrodes, and each having at least a first and a second fixed terminal. switch, and first and second power switches, one terminal of which is connected to the first and second fixed terminals of the first power switch that are commonly connected.
a switching transistor having a collector-emitter path connected between the other terminal of the first load and a first terminal of the second power switch; and the first and second loads. a switching diode connected between each other terminal of the switching transistor, and a control signal generator coupled to the base side of the switching transistor;
The second terminal of the power switch and the other terminal of the second load are connected to ground, and the first and second loads are simultaneously driven by the first and second power switches, or the first and second loads are simultaneously driven by the first and second power switches. A load driving circuit, characterized in that the load is driven by the output of the control signal generator.