JPS6329419A - Power source switch - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to household electrical appliances, particularly power switchgears for washing machines, dryers, and the like.

2. Description of the Related Art Conventionally, this type of power switchgear has had a configuration as shown in FIG. In Fig. 3, 11 is an AC power supply;
2 is a push button switch, 13 is a switching device, and a coil R of a relay 14 is connected in series with the switching device 13.

The control contacts of the relay 14 are connected to the push button switch 12.
and are connected in parallel relationship. The control circuit 16 and the load circuit 1 are connected to the AC power supply 11 via the push button switch 12.
Power is supplied to 6. The switching device 13 is a semiconductor switching device such as a bidirectional thyristor (abbreviated as TRIAC), and the control circuit 15 controls the TRIAC and the like. When push button switch 13 is pressed,
Power is supplied to the control circuit 16, the control circuit 15 drives the triac 13, and the triac 13 drives the relay 1.
Drive 4. The control contacts of the relay 14 are connected in parallel with the pushbutton switch 12, so even if the pushbutton switch 12 is released, the control circuit 1 is not connected to the contact of the relay 14.
6 and the relay coil R enter a holding state in which power is supplied. When turning off the power, it is sufficient to cut off the drive signal from the control circuit 16 to the triac 13. Problems to be Solved by the Invention In such a conventional configuration, it is necessary to always drive the relay coil R. For example, if there is a momentary power outage, the relay will turn off and will not return until the push button switch 12 is closed again.
Further, even if a semiconductor having an amplifying effect such as the triac 13 is used, the driving power of the triac 13 increases the power supply of the control circuit 15, resulting in an increase in price.

The present invention is intended to solve these problems, and aims to prevent the power supply from being turned off even in the event of a momentary power outage, and to reduce the burden on the power supply circuit of the control circuit.

Means for Solving the Problems In order to achieve the above objects, the power switch of the present invention has a mechanical holding mechanism, which includes a power switch that is turned on in the held state, and which releases the mechanical holding mechanism of the power switch. It has an electromagnetic coil, and a load circuit and a control circuit to which power is supplied via the power switch, and the control circuit controls power supply from the power switch to the load circuit and the electromagnetic coil via a switching device. In addition, the switching device for supplying power to the electromagnetic coil is configured to be driven in a short period.

Effect: This configuration eliminates the need for electric power to self-hold the power switch, and current is passed through the switch device in short periods only when the power switch is cut off, so the power supply for the control circuit can be made smaller.

Furthermore, even in the event of a momentary power outage, the power supply will not be cut off.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 and 2. In this embodiment, a case where the present invention is applied to a fully automatic washing machine for washing household clothes is shown. In FIG. 1, an AC power source 1, a contact 2a of a power switch 2, and switching devices 3a and 3b are connected in series to supply power to a motor 7.

Switching devices 3a and 3b are connected to the main winding and auxiliary winding of the motor, and a switching device W30 for controlling forward and reverse rotation is connected to the drainage magnet 9 and the switch.

The switching device 3d drives the water supply valve 1Q, and the switching device 3e drives the electromagnetic coil 2b of the power switch 2.When the power switch 2 is pressed, the contacts are closed and mechanically held, and power is supplied to the control circuit 6, and the switching device 3e drives the electromagnetic coil 2b of the power switch 2. According to the programmed sequence, the motor starts, the drainage magnet 9,
The water supply valve 10 operates. During normal operation of the product, the electromagnetic coil 2b is not driven, and after a certain period of time after the end of operation (
For example, after 10 minutes), the electromagnetic coil 2b is periodically connected to the electromagnetic coil 2b for a certain period of time (for example, after 10 minutes) as shown in FIG.
50-100m58C) Electric power is supplied, the mechanical launch which is a mechanical holding function is removed, and the power switch 2 is cut off. Period T. is approximately 1 second, and the pulse width T is optimally 60 to 100 m5ec as mentioned above. This is because the time T1 for driving the electromagnetic coil 2b only needs to be longer than the operating time of the electromagnetic coil 2b (usually 20 m5ec). However, if the latch does not release,
One pulse may not cut it off, so if you drive it several times,
You can always release the latch. If the pulse width is increased, the electromagnetic coil 2b may be burnt.

Note that the electromagnetic coil 2b is energized continuously rather than in pulses.
If the electromagnetic coil 2b is driven, the risk of burning the electromagnetic coil 2b becomes even greater.

Effects of the Invention As is clear from the description of the embodiments, the present invention uses an electromagnetic coil to release the mechanically held power switch, so no electric power is required to hold the power switch. The current consumption of the power supply circuit of the control circuit can be reduced. In particular, when the power is cut off, the switching device is driven in short periods to release the holding state by the electromagnetic coil, so the energy used is very small.

In addition, in order to drive the switching device in short periods,
There is no risk that the electromagnetic coil will become saturated and generate heat, causing the electromagnetic coil to burn out. Therefore, the electromagnetic coil can be miniaturized and an inexpensive power switch device can be realized.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram of a power switching device applied to a fully automatic machine that is an embodiment of the present invention, and Fig. 2 is a diagram showing the waveform of the driving current when the power switching device is cut off. , Fig. 3 is a circuit diagram of a conventional power switchgear. 0 1...AC power supply, 2...power switch, 2b-
゛.・Electromagnetic carp/pe32L~3e...Switching device, 6...Control circuit. Name of agent: Patent attorney Toshio Nakao and one other person? −
--11 no λ switch + Figure 2

Claims (1)

[Claims] The power switch has a mechanical holding mechanism and is turned on in a holding state, an electromagnetic coil that releases the mechanical holding mechanism of the power switch, and a load circuit and a control circuit to which power is supplied via the power switch. The control circuit controls power supply from the power switch to the load circuit and the electromagnetic coil via a switching device, and
A power switching device that drives a switching device that supplies power to the electromagnetic coil in short periods.