JPS6149996B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a so-called microcomputer-equipped washing machine that has an electronic timer.

FIG. 1 shows the panel operation section of a washing machine with a microcomputer. Reference numeral 10 is an operation panel, and 20 is a power switch, which is composed of two push buttons for "on" and "off". 30 is a keyboard. 40 is a water level switch.

FIG. 2 is an example of a conventional circuit. 22 is a power switch. 24, which is closer to the power supply, is the OFF switch, and 26 is the ON switch. 50 is a power supply reed relay. 60 is a load reed relay. A washing machine has loads such as a motor, a drain valve, a water supply valve, etc., and these are representatively placed on the circuit as 90 loads. 70 is a transformer. 80 is a control circuit composed of a microcomputer and the like. The left side indicated by a thick broken line is a component that cannot be mounted on a printed circuit board. When the ON switch 26 is pressed, 100V AC is applied to the primary side of the transformer 70. As a result, the control circuit 80 starts working, and first the Q1 transistor is turned on to form a self-holding circuit.
A current that turns on the power supply reed relay 50 flows through the coil of the reed relay 50. Therefore, the reed switch inside turns on, gate current flows to the gate of FLS1, and FLS1 turns on. Therefore ON
Even if the switch 26 is released, a self-holding circuit is formed and automatic operation becomes possible. R and C connected in parallel with FLS1 are for surge absorption. The FLS2 operates according to commands from the control circuit 80 depending on the timing.

FIG. 3 is a configuration diagram of the power switch 20. 1
00 is a panel board. A switch frame 110 is fixed to the panel board 100 with set screws 120. An ON switch 26 and an OFF switch 24 are fixed to the switch frame 110. 130 lead wires are soldered to the two switches.

In the above, it is preferable to use as few components as possible in order to simplify the wiring, but the large power switch 22 that cannot be mounted on a printed circuit board has been a factor in increasing costs. Therefore, if this power switch 22 can be mounted on the board, the wiring can be reduced and costs can be reduced.

FIG. 4 is a circuit of an embodiment of the present invention. 28
is an on-board power switch. 140 OFF reed switches are incorporated in series with the contact circuit of the power supply reed relay 50. As can be seen in FIG. 4, the power switch is placed to the right of the thick broken line, simplifying the circuit.

FIG. 5 is an external view of the power supply reed relay 50 and reed switch 140.

FIG. 6 is a cross-sectional view of an embodiment of the invention. 1
50 is the key top for OFF. 155 is OFF
It is a magnet for OFF and a key top 150 for OFF.
is fixed at the bottom of the A push spring 170 is arranged to press the upper part of the key top against the panel board 100, and is held by a switch base 180. When no force is applied to the OFF key top 150, the OFF reed switch 14
At 0, the contact is turned on by the magnetic force of the OFF magnet. When you press the key top, the contact opens and turns off.
become. 160 is the key top for ON, and on the bottom,
The ON magnet 165 is fixed and placed directly above the power supply reed relay 50, and when the key top is not pressed, the reed switch inside is closed.
It is in the OFF state, but if you press the key top, the reed switch will turn ON.

Both the OFF reed switch 140 and the power reed relay 50 are soldered to the printed circuit board 190. A control circuit is mounted on this printed board.

FIG. 7 shows another embodiment. In this figure, the reed relay is omitted and the FLS is directly switched by the transistor Q1 of the control circuit. As in Figure 8, the ON and OFF switches are mounted on the board and can be turned ON and OFF using similar key-top switches. The ON reed switch of the 200 is the same as the ON key top in Figure 6, when the key top is not pressed.
OFF, configured to turn ON when pushed in. In this case, component costs are lower than in the circuit shown in FIG. 4, and an inexpensive power switch can be provided.

According to the above configuration, the power switch, which was conventionally independent from the printed circuit board, is now mounted inside the printed circuit board, which reduces the number of lead wires connecting the switch and the board by two, and also simplifies the mechanism of the power switch. Therefore, it has the effect of lowering the total cost.

Furthermore, since the current flowing through the ON switch 26 in Fig. 2 was only the excitation current of the primary side of the transformer 70, the current flowing through the contact when the switch was pressed was only 20 mA, making it impossible to obtain sufficient contact reliability. . In other words, to maintain high reliability at 20mA, it is better to use gold contacts, or use a switch designed for low current, such as a reed switch. However, gold contacts are expensive, and reed switches are made of glass, making it difficult to incorporate them into ordinary switches.

In this respect, according to the present invention, the effects of both cost reduction and reliability improvement can be obtained.

[Brief explanation of the drawing]

Figure 1 is an operation panel diagram of a microcomputer washing machine, Figure 2 is a conventional circuit diagram, Figure 3 is an external view of a conventional power switch, Figure 4 is a circuit diagram of the present invention, and Figure 5. 6 is an external view of a reed relay and a reed switch, FIG. 6 is a configuration diagram of the present invention, and FIG. 7 is another applied circuit diagram. 28...Power switch, 50...Reed relay, 140...Reed switch.

Claims (1)

[Scope of Claims] 1. Regarding a self-holding circuit that maintains the primary side of a transformer in a conductive state in a washing machine that has an electronic timer and automatically operates from water supply to washing, rinsing, and spin-drying, a self-holding circuit such as FLS etc. is used for self-holding. A washing machine characterized in that two sets of external operation switches, a normally closed OFF switch and a normally open ON switch, are arranged in series in a self-maintaining signal circuit using elements with the same function such as elements or relays. power switch. 2. The washing machine according to claim 1, characterized in that a reed relay is used as a normally open ON switch of a self-maintaining signal circuit, and an ON key top is disposed directly above the reed relay. Machine power switch.