JPH10261483A - Electric apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric apparatus for which vain electric current consumption is eliminated in an operation waiting state of an operation control circuit. SOLUTION: A main switch 2 is switched to a contact 2c side when a door is opened and an electric power is supplied to control circuit 5 through a transformer 3 and an electric current rectifying circuit 4. A CPU 6 is operated and a transistor 14 is turned on. Electric current flows in a relay coil 15 and a relay switch 15a is turned on. Even when the door is closed and the main switch 2 is switched to a contact 2b side, electric current flows in the control circuit 5 through the switch 15a. When a prescribed passes, the transistor 14 is turned off by a timer circuit 7 and the switch 15a is also turned off, so that electric power supply to the control circuit is stopped. In the case that a heating instruction is sent to a key 11 before the prescribed time passes, the CPU 6 continuously keeps the transistor 14 in ON state, so that the switch 15a is also kept in ON state and electric power supply to the control circuit is retained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electric equipment such as a microwave oven.

[0002]

2. Description of the Related Art In a conventional electric device, for example, a microwave oven, when an insertion plug is inserted into a power outlet, a power supply transformer and an operation control circuit are always used even when not used for cooking. Since the power supply voltage is applied, the circuit configuration is such that a power supply current is supplied to the CPU, various sensors, the display tube, and the like in the internal control circuit via the power supply transformer.

[0003]

Therefore, in the microwave oven having the above-described circuit configuration, even when the microwave oven is not used for cooking, the current is always supplied to the power transformer and the operation control circuit. Loss, copper loss, and the like, and the circuit system such as the CPU consumes nearly 10 W of power.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and an electric apparatus according to the first aspect of the present invention controls a load and drives the load. In an electric apparatus comprising a control unit, a power supply for supplying power to the control unit, and a switch unit for controlling ON / OFF of power supply from the power supply to the control unit, the switch unit is turned on for a predetermined time. Holding means for holding,
And a self-return type start switch for starting the holding means.

According to this configuration, when the holding means is started by the self-return type start switch, the switch means is turned on.
Since the state is maintained, power is supplied to the control means.
In this state, if the load is not started, the switch means is turned off after a lapse of a predetermined time, power supply to the control circuit is cut off, and power is saved.

According to a second aspect of the present invention, there is provided the electric apparatus according to the first aspect, further comprising a door, wherein the self-return type start switch starts the holding means in accordance with the operation of the door. It is characterized by being comprised of a door switch to be turned on.

[0007] For example, in a microwave oven or the like, it is usual that an opening / closing operation of a door is performed for putting foods before operating a heating means (load). Therefore, if there is an operation of the door, it is necessary to enter the standby state.
Since the start switch is operated by opening and closing the door, the standby state is automatically realized with the operation of the door.

According to a third aspect of the present invention, there is provided the electric device according to the first aspect, further comprising: another holding means for holding the switch in an ON state at all times; and the switch means by the holding means. Switching means for switching to one of a first mode for holding the switch means and a second mode for holding the switch means by the other holding means. Therefore, according to this configuration, the first mode and the second mode can be selected.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings.

[Configuration] FIG. 1 is an electric circuit diagram showing an embodiment of a microwave oven equipped with a low power consumption circuit device according to the present invention at the time of operation standby. In the drawing, reference numeral 1 denotes a commercial AC power supply. The plug 2 is a main switch having the movable terminal 2a connected to one terminal of the plug 1, and the movable terminal 2a is connected to the fixed terminal 2b or 2c according to the opening and closing of a microwave oven door (not shown). Switching operation is performed. That is, when the door is closed, the movable terminal 2a is turned on to the fixed terminal 2b, and when the door is opened, the movable terminal 2a is turned on to the fixed terminal 2c.

A power transformer 3 has one terminal of a primary coil 3a connected to the fixed terminal 2c and also connected to one terminal of the plug 1 via a relay switch 15a. The other terminal of the primary coil 3a is connected to the other terminal of the plug 1.
The secondary coil 3b of the power transformer 3 is connected to the rectifier circuit 4 so that the output voltage of the secondary coil 3b is rectified by the rectifier circuit 4 and supplied to the operation control circuit 5.
The operation control circuit 5 includes a CPU 6, a clock circuit 7, a heating control circuit 8, and the like. The CPU 6 has a built-in timer.

When a power supply voltage is applied from the rectifier circuit 4 through the input terminal 6a, the CPU 6 supplies a high-level signal S1 to the base of the transistor 14. As a result, the transistor 14 is turned on, and the relay coil 1 is turned on.
5, and the relay switch 15a keeps the ON state. Therefore, even if the door is closed and the main switch 2 is switched to the side 2b, the power is continuously supplied to the control circuit 5 because the relay switch 15a is kept ON. CP
U6 also starts a timer and supplies a clock signal S2 to the clock circuit 7 to operate the circuit 7.

When the standby power saving mode, which will be described later, is set, the signal S1 is stopped after a lapse of a predetermined time by a timer. As a result, the relay switch 15a is turned off, and power is not supplied to the control circuit 5.
On the other hand, when the constant control mode described later is set, the signal S1 is continuously generated. As a result, the relay switch 15a remains ON, and continues to supply power to the control circuit 5. Switching between the two modes is performed by the operation panel 9
This is done by the upper switching key 12.

When the constant control mode is set, the CPU 6 causes the clock circuit 7 to supply a time signal to the time display section 10 of the operation panel 9.
The CPU 6 also operates the heating start key 11 on the operation panel 9.
Is turned on, a heating command signal S4 is supplied to the heating control circuit 8 based on this, and the heating control circuit 8 causes the heating means (magnetron) 13 as a load to output a heating start signal S5. The CPU 6 has a built-in EEPROM, and switches the setting mode for writing to the EEPROM with the switching key 12 to the standby power saving mode or the constant control mode.

The present invention is configured as described above, and its operation will be described below with reference to FIG. First, a user inserts the insertion plug 1 into a power outlet. The CPU 6 determines whether or not the door has been opened in step K5. This determination is made based on whether or not the input voltage has entered. That is, when the door is opened, the movable terminal 2a of the main switch 2 is turned on to the fixed terminal 2c, and the power supply voltage is supplied to the CPU 6 via the power supply transformer 3 and the rectifier circuit 4.

The CPU 6 starts a timer, outputs a relay drive signal S1 to turn on the switching transistor 14, and energizes the relay coil 15 to turn on the relay switch 15a (step K1).
0). For this reason, even when the door is closed and the movable terminal 2a of the main switch 2 is turned on to the fixed terminal 2b, the power supply voltage is supplied to the power transformer 3 through the relay switch 15a. Can be maintained.

Next, the standby power saving mode is switched by the key 1
(Step K1)
5). If the standby power saving mode has been set, the process proceeds to step K20, where it is determined whether or not a predetermined time measured by the timer has elapsed.
Then, the relay switch 15a is turned off. The relay switch 15a is turned off by the CPU 6 stopping the drive signal S1 to turn off the transistor 14.

If the predetermined time has not elapsed in step K20, the process proceeds to step K25, in which a heating condition is instructed (this instruction is made by the heating key 11).
Wait for. Thereafter, it is determined in step K30 whether or not a heating start instruction has been issued, and if so, the heating control means performs heating control via the heating control circuit 8 (step K35). If there is no instruction, the process returns to step K20. Step K3
When heating is controlled in step 5 and heating is completed in step K40,
Proceeding to step K45, the relay switch 15a is turned off.
F.

If the standby power saving mode is not set in step K15, the routine of steps K50 to K75 (routine of the constant control mode) is executed, and the process returns to step K15. This routine is significantly different from the power saving mode routine (K20 to K40) in that the clock circuit 7 is driven to display the time (step K55).
The point is that when the last step K75 is executed, the process returns to the step K15.

In the above-mentioned embodiment, the holding means in the first embodiment is constituted by the transistor 14, the relay coil 15, and the CPU 6 in this embodiment. Note that the switch 15a may be configured by a semiconductor switch circuit.
In that case, the relay coil 15 becomes unnecessary. Also,
Although a commercial AC power supply is planned as the power supply of the control circuit 5, a battery may be used as the power supply of the control circuit 5 when the heating means 13 and the power supply of the control circuit 5 are different power supplies. The other holding means according to claim 3 is constituted by the transistor 14, the relay coil 15, and the CPU 6 when the control mode is always selected by the switching key 12. At this time, the CPU 6 continues to output the signal S1 without aborting.

[0021]

The present invention is constructed as described above. According to the first aspect of the present invention, unnecessary current consumption can be prevented from flowing in the standby state of the operation.
Power consumption can be reduced.

According to the invention described in claim 2,
Since the start switch is operated by opening and closing the door, the standby state is automatically realized with the operation of the door. Thereafter, the above-described effects are obtained.

According to the third aspect of the present invention,
A first mode in which an ON / OFF switch is always kept in an ON state; and a first mode in which the load is started while the first holding means keeps the ON / OFF switch in an ON state for a predetermined time. The second mode in which the OFF switch means is always ON can be arbitrarily selected by the switching means.

[Brief description of the drawings]

FIG. 1 is an electric circuit diagram showing an embodiment of a current consumption reduction circuit in an operation standby state in an electric device according to the present invention.

FIG. 2 is a flowchart provided for explaining the operation of the current consumption reduction circuit in the electric device according to the present invention during an operation standby state;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 insertion plug 2 main switch 3 power transformer 5 operation control circuit 6 CPU 7 clock circuit 8 heating control circuit 9 operation panel 10 time display section 11 heating key 12 switching key 13 heating means 14 transistor 15 relay coil

Claims (3)

[Claims] 1. A load, control means for controlling driving of the load, a power supply for supplying power to the control means, and switch means for controlling ON / OFF of power supply from the power supply to the control means. The electric device according to claim 1, further comprising: a holding unit that holds the switch unit in an ON state for a predetermined time; and a self-return type start switch that starts the holding unit. 2. The electric apparatus according to claim 1, further comprising a door, wherein said self-return type start switch comprises a door switch for starting said holding means in accordance with operation of said door. 3. A first mode in which the switch is held by the other holding means, a first mode in which the switch is held by the holding means, and a second mode in which the switch is held by the other holding means. 2. The electric device according to claim 1, further comprising a switching unit for switching to one of the two modes.