JP7573148B2 - Operation control device for household electrical appliances and washing machine - Google Patents

Description

The present disclosure relates to an operation control device for a household electrical appliance having a load that operates on a commercial AC power source , and a washing machine .

Patent Document 1 discloses a power supply device that converts commercial AC power to a constant low voltage using an isolation transformer to determine whether the commercial AC power voltage connected to the device is outside the rated voltage range, and then supplies the voltage to a control device. It also discloses a means for detecting misuse by the user and protecting the device by detecting abnormal voltage using a separately provided detection circuit.

Japanese Patent Application Publication No. 04-187180

This disclosure provides an operation control device for household electrical appliances that detects the commercial AC power supply voltage connected to the appliance without the need for a special detection circuit to determine whether the voltage is outside the rated voltage, and by forcibly shutting down the appliance in the event of an abnormality, prevents unsafe conditions and improves safety.

The operation control device for a household electrical appliance in the present disclosure comprises a rectifier that rectifies a commercial AC power supply, a voltage conversion device that converts the voltage rectified by the rectifier into an arbitrary output voltage, an output voltage conversion device that converts the output voltage into a signal at a predetermined ratio, a voltage control device that controls the voltage conversion device so as to keep the output voltage constant by a signal from the output voltage conversion device, an intermittent oscillation means provided in the voltage control device and having a function of performing an intermittent oscillation operation under light load, an AC load operated by the commercial AC power supply, a switch that opens and closes the connection between the AC load and the commercial AC power supply, a control means that controls the AC load by controlling the opening and closing of the switch to sequentially control a predetermined operating process, a voltage detection means provided in the control means and reading a signal from the output voltage conversion device, and a timing means provided in the control means for measuring a switching period of a ripple voltage appearing in the output voltage, and the control means is configured to not connect the switch to the AC load and to stop operation if the switching period exceeds a predetermined value.

The operation control device for household electrical appliances disclosed herein detects the commercial AC power supply voltage connected to the appliance without the need for a special detection circuit to determine whether the voltage is outside the rated voltage, and by stopping the appliance and issuing an alarm in the event of an abnormality, it is possible to prevent unsafe conditions and improve safety.

A circuit diagram of an operation control device for a household electrical appliance, exemplifying a washing machine in the first embodiment. FIG. 1 is a diagram showing the operation of control signals to switching elements of an operation control device for a household electric appliance according to the first embodiment.

(The knowledge and other information that formed the basis of this disclosure)
In the conventional configuration, a power supply circuit for supplying power to other loads and a commercial AC power supply voltage detection circuit are separately required, which leads to an increase in circuit size and cost. In addition, even when the device is not in operation, the detection circuit continues to operate as long as the commercial AC power supply remains connected, which increases the power consumption during standby. In order to solve this problem, the subject of the present disclosure has been constituted.

The present disclosure provides an operation control device for household electrical appliances that detects the commercial AC power supply voltage connected to the appliance without providing a special detection circuit for determining whether the voltage is outside the rated voltage, and forcibly stops the appliance in the event of an abnormality, thereby preventing unsafe conditions and improving safety.

Below, the embodiments will be described in detail with reference to the drawings. However, more detailed explanation than necessary may be omitted. For example, detailed explanation of already well-known matters or duplicate explanation of substantially the same configuration may be omitted. This is to avoid the following explanation becoming unnecessarily redundant and to make it easier for those skilled in the art to understand.

The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

(Embodiment 1)
Hereinafter, the first embodiment will be described with reference to FIGS.

(1-1. Configuration)
In FIG. 1, an operation control device 20 rectifies AC power from a commercial AC power source 1 using a rectifier 2 , and converts the DC voltage into a predetermined output voltage Vo using a voltage conversion device 4 including a switching element 5 and a transformer 6 .

The output voltage converter 7 converts the output voltage Vo into a signal, and the voltage control device 3 controls the voltage converter 4 to maintain a constant output voltage Vo based on a feedback signal from the output voltage converter 7. The voltage control device 3 also has a function of suppressing switching loss due to the switching element 5 and reducing standby power consumption by performing intermittent oscillation operation using the intermittent oscillation means 19 when the device is in a light load state, such as when the device is in a standby state.

The output voltage Vo from the voltage conversion device 4 supplies power to other control circuits (not shown) and also to the control means 9.

The switch 11 controls the flow of electricity between the commercial AC power source 1 and AC loads 12, such as a washing tub (not shown) that holds the laundry in the washing machine, a motor 17 that drives and rotates a pulsator (not shown) that agitates the laundry, and a water supply valve 18 that supplies water to the washing tub. When the switch 11 is closed, power is supplied from the commercial AC power source 1 to the AC loads 12, and the AC loads 12, such as the motor 17 and the water supply valve 18, start operating at a predetermined timing. Note that loads other than the motor 17 and the water supply valve 18 are not shown.

The control means 9 controls the opening and closing of the switch 11 by sending and stopping a signal to the switch 11 using the switch opening and closing control means 15, and also receives a feedback signal from the output voltage conversion device 7 together with the voltage control device 3.

The voltage detection means 14 provided in the control means 9 reads the signal from the output voltage conversion device 7, and the timing means 13 also provided in the control means 9 performs various timing operations, such as measuring the switching period Tsw of the ripple voltage ΔVo appearing in the output voltage Vo from the voltage conversion device 4.

The switch 11 remains open until a switch-closing signal is received from the control means 9, and the AC load 12 is disconnected from the commercial AC power supply 1. The disconnection between the AC load 12 and the commercial AC power supply 1 continues even when the commercial AC power supply 1 is not connected and the device is completely stopped operating.

The load isolation rectifier 8 and smoothing capacitor 10 are intended to isolate the current from other loads in order to supply a stable power supply voltage to the control means 9 and a voltage that serves as a reference voltage within the control means 9. However, if a stable power supply is provided to the control means 9 from a separate power source, the load isolation rectifier 8 and smoothing capacitor 10 are not necessary.

In addition, if the control means 9 determines that the power supplied to the commercial AC power source 1 is an unrated voltage and is unsafe for the equipment, the control means 9 notifies the user of the abnormality via the abnormality notification means 16. Voltage detection will be described later.

(1-2. Action, action)
The operation and function of the operation control device for domestic electric appliances configured as above will be described below.

When a user connects the device to the commercial AC power supply 1, the voltage converter 4 supplies a constant output voltage to the control means 9 under the control of the voltage control device 3. Immediately after the user connects the device to the commercial AC power supply 1, the device is in a standby state.

In the standby state, the AC load 12 does not operate, and only some of the control means 9 necessary to maintain the standby state are operating, resulting in a light load, and the voltage control device 3 performs control to suppress standby power by intermittent oscillation. In the standby state, the power is low as described above, and there is little change in power due to other external factors.

Figure 2 shows the operation of the control signals to the switching element 5 in normal operation and standby mode. During standby operation, the switching period Tsw of the ripple voltage ΔVo becomes longer to suppress switching losses compared to normal operation, and the output ripple voltage ΔVo becomes larger. Furthermore, the controlled switching period Tsw depends on the commercial AC power supply 1. Generally, when the voltage conversion device is a step-down type, the higher the input voltage, the longer the switching period Tsw.

The switching period Tsw of this ripple voltage ΔVo is input to the control means 9, and the switching period Tsw is measured by the timer means 13 inside the control means 9, so that the voltage of the commercial AC power supply 1 can be estimated. If the switching period Tsw is longer than the predetermined switching period Tsw and the voltage of the commercial AC power supply 1 is determined to be outside the rated voltage, the switch opening/closing control means 15 inside the control means 9 does not send a signal to close the switch 11, and the switch 11 remains open, continuing to cut off the commercial AC power supply 1 to the motor 17, water supply valve 18, etc. of the AC load 12. This makes it possible to prevent unsafe failures of the AC load 12 due to abnormal voltage.

In addition, if the control means 9 determines that the voltage of the commercial AC power supply 1 is outside the rated voltage, it does not send a signal to close the switch 11, and not only continues to cut off the connection between the AC load 12 and the commercial AC power supply 1, but also sends a signal from the control means 9 to the abnormality notification means 16 to notify the user of the abnormality.

(1-3. Effects, etc.)
As described above, in this embodiment, when the switching period Tsw of the ripple voltage ΔVo of the commercial AC power supply 1 measured by the timer means 13 provided in the control means 9 exceeds a predetermined value, the voltage of the commercial AC power supply 1 is determined to be outside the rated voltage, the switch 11 is not connected to the AC load 12, and operation is stopped.

This will prevent unsafe situations and improve safety.

Furthermore, as in this embodiment, when the switching period Tsw of the ripple voltage ΔVo of the commercial AC power supply 1 measured by the timing means 13 exceeds a predetermined value and the voltage of the commercial AC power supply 1 is determined to be an unrated voltage, the abnormality notification means 16 is configured to notify an abnormality.

This will prevent unsafe situations and improve safety.

This disclosure is applicable to household electrical appliances such as washing machines that have a load that operates on a commercial AC power source. Specifically, this disclosure is applicable to top-loading washing machines, drum-loading washing machines, dishwashers, etc.

REFERENCE SIGNS LIST 1 Commercial AC power supply 2 Rectifier 3 Voltage control device 4 Voltage conversion device 5 Switching element 6 Transformer 7 Output voltage conversion device 8 Rectifier for load isolation 9 Control means 10 Smoothing capacitor 11 Switch 12 AC load 13 Time measuring means 14 Voltage detection means 15 Switch opening/closing control means 16 Abnormality notification means 17 Motor 18 Water supply valve 19 Intermittent oscillation means 20 Operation control device

Claims (3)

A rectifier that rectifies a commercial AC power supply;
a voltage conversion device for converting the voltage rectified by the rectifier into an arbitrary output voltage;
an output voltage conversion device that converts the output voltage into a signal at a predetermined ratio;
a voltage control device that controls the voltage conversion device based on a signal from the output voltage conversion device so as to keep the output voltage constant;
an intermittent oscillation means provided in the voltage control device and having a function of performing an intermittent oscillation operation under a light load;
an AC load operated by the commercial AC power supply;
a switch for opening and closing a connection between the AC load and the commercial AC power supply;
A control means for controlling the AC load by controlling the opening and closing of the switch to sequentially control a predetermined operation process;
a voltage detection means provided in the control means for reading a signal from the output voltage conversion device;
a timer means provided in the control means for measuring a switching period of a ripple voltage appearing in the output voltage ;
The control means is an operation control device for a household electrical appliance that stops operation by not connecting the switch to the AC load when the switching period exceeds a predetermined value. 2. The apparatus according to claim 1, wherein the control means notifies an abnormality by an abnormality notifying means when the switching period measured by the timer means exceeds a predetermined value. A rectifier that rectifies a commercial AC power supply;
a voltage conversion device for converting the voltage rectified by the rectifier into an arbitrary output voltage;
an output voltage conversion device that converts the output voltage into a signal at a predetermined ratio;
a voltage control device that controls the voltage conversion device based on a signal from the output voltage conversion device so as to keep the output voltage constant;
an intermittent oscillation means provided in the voltage control device and having a function of performing an intermittent oscillation operation under a light load;
an AC load which is at least a motor or a water supply valve and is operated by the commercial AC power source;
a switch for opening and closing a connection between the AC load and the commercial AC power supply;
A control means for controlling the AC load by controlling the opening and closing of the switch to sequentially control a predetermined operation process;
a voltage detection means provided in the control means for reading a signal from the output voltage conversion device;
a timer means provided in the control means for measuring a switching period of a ripple voltage appearing in the output voltage;
When the switching period exceeds a predetermined value, the control means does not connect the switch to the AC load and stops operation.
washing machine.