JP5768207B2 - Cooking equipment - Google Patents

Description

  The present invention relates to a cooking appliance that reduces power consumption in a standby state where the appliance is not performing a heating operation.

  In recent years, in household appliances including cooking appliances, it has been an important issue to reduce power consumption. In particular, there is a technology aimed at reducing power consumption when equipment is not in operation, so-called standby power. It has been proposed (see, for example, Patent Document 1).

  FIG. 4 shows a conventional induction heating apparatus which is a kind of cooking appliance described in Patent Document 1. Hereinafter, the configuration will be described.

  As shown in FIG. 4, the first power supply circuit 41 outputs a DC voltage by converting a DC voltage smoothed after half-wave rectification of the commercial power supply 42 with a step-down chopper, and this first power supply circuit 41. Is controlled by a detection signal of a feedback circuit.

  The feedback circuit includes a photocoupler 43a and a voltage setting unit connected to a light emitting diode in the photocoupler 43a. When the output voltage of the first power supply circuit 41 exceeds the voltage obtained by adding the forward voltage of the light emitting diode in the photocoupler 43a to the voltage of the voltage setting unit, the phototransistor in the photocoupler 43a becomes conductive, and the detection signal of the feedback circuit is Is output. When the first power supply circuit 41 receives the detection signal of the feedback circuit, the output is stopped. Therefore, the output voltage of the first power supply circuit 41 is defined by a voltage obtained by adding the forward voltage of the light emitting diode in the photocoupler 43a to the voltage of the voltage setting unit.

  The power supply voltage changing unit 44 switches the output voltage of the first power supply circuit 41 between a first voltage setting value (for example, 20 V) and a second voltage setting value (for example, 10 V) lower than the first voltage setting value. Is for. When the transistor 44c of the voltage setting unit composed of the Zener diode 44a, the Zener diode 44b, and the transistor 44c is turned off, the Zener diode 44a and the Zener diode 44b are connected in series, and the set value of the output voltage of the first power supply circuit 41 is The first voltage setting value is defined by the light emitting diode in the photocoupler 43a, the Zener diode 44a, and the Zener diode 44b. On the other hand, when the transistor 44c of the voltage setting unit is turned on, the Zener diode 44b is short-circuited, and the set value of the output voltage of the first power supply circuit 41 is defined by the light emitting diode and the Zener diode 44a in the photocoupler 43a. This is the second voltage setting value. A resistor 44d inserted between the collector of the transistor 44c and the cathode of the Zener diode 44b switches the set value of the output voltage of the first power supply circuit 41 from the first voltage set value to the second voltage set value. This is a resistor for preventing the current exceeding the rated current from flowing through the Zener diode 44a immediately after.

  The microcomputer 45 is provided with a power supply voltage changing function 45a and a wake-up means 45b. The power supply voltage changing function 45a is for switching the set value of the output voltage of the first power supply circuit 41 according to the state of the device. This function outputs an on / off signal to the transistor 44c. During standby when the device is not performing the heating operation, the set value of the output voltage of the first power supply circuit 41 is set as the second voltage set value, thereby reducing the power consumption of the device during standby.

The wake-up means 45b outputs a signal to the power supply voltage changing function 45a when the user performs an operation on the operation unit 46 while the apparatus is not performing the heating operation, and the power supply voltage changing function 45a. Receives the signal from the wake-up means 45b and switches the set value of the output voltage of the first power supply circuit 41 from the second voltage set value to the first voltage set value.

JP 2006-156147 A

  However, in such a conventional configuration, the light emission in the photocoupler 43a of the feedback circuit each time the set value of the output voltage of the first power supply circuit 41 is switched from the first voltage set value to the second voltage set value. A large current flows through the diode. This causes a problem that the light emitting diode in the photocoupler 43a is deteriorated and the reliability of the device is lowered.

  This invention solves the said subject, and is for improving the reliability of the cooking appliance which reduced the power consumption in the standby state in which the appliance is not performing heating operation.

In order to achieve the above object, the cooking appliance of the present invention converts electric power supplied from a commercial power source into a predetermined DC voltage by a signal from an output voltage detection means that outputs a signal corresponding to an input voltage. A first power supply circuit that outputs the output voltage, output voltage switching means for switching an output voltage of the first power supply circuit between a first voltage set value and a second voltage set value lower than the first voltage set value, and a counting means for counting the time elapsed after switching to the first voltage set value the output voltage of the first power supply circuit from the second voltage set value, the measured time of the timer means Tokoro for more than scheduled the until it is obtained, which prevents switching to the second voltage set value the output voltage of the output voltage switching means the first power supply circuit from the first voltage set value.

Thus, the number of times that a large current flows can place restrictions on the light emitting diode in the optocoupler feedback circuit the output voltage detection means of the first power supply circuit, a light emitting diode in the photocoupler according to a large current flows Therefore, the reliability of the first power supply circuit can be improved, and as a result, the reliability of the cooking appliance can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, the highly reliable cooking appliance which reduced the power consumption in a standby state can be provided.

Main unit configuration diagram of cooking appliance according to Embodiment 1 of the present invention The circuit diagram which made the cooking appliance in Embodiment 1 of this invention into the partial block Main part operation | movement flowchart of the cooking appliance in Embodiment 1 of this invention Partial block diagram of conventional cooking equipment

According to a first aspect of the present invention, there is provided a first power supply circuit that converts electric power supplied from a commercial power supply into a predetermined DC voltage and outputs the signal by a signal from an output voltage detecting means that outputs a signal corresponding to an input voltage, and the first Output voltage switching means for switching an output voltage of the power supply circuit between a first voltage setting value and a second voltage setting value lower than the first voltage setting value; and an output voltage of the first power supply circuit as the second voltage setting value. Timing means for measuring an elapsed time since switching from the voltage setting value to the first voltage setting value, and the output voltage switching means is the first voltage until the time measured by the timing means reaches a predetermined time or more. By limiting the output voltage of the power supply circuit from the first voltage setting value to the second voltage setting value, it is possible to limit the number of times that a large current flows in the feedback circuit as the output voltage detection means. Can Because it reduces the load on the fed back circuit, it is possible to improve the reliability of the cooking appliance.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a configuration diagram of a main body of a cooking appliance according to the first embodiment of the present invention. FIG. 2 is a partial block diagram of the cooking appliance according to Embodiment 2 of the present invention. FIG. 3 is a main part operation flowchart of the cooking appliance according to Embodiment 2 of the present invention.

  As shown in FIG. 1, a pot 1 for putting an object to be cooked such as water or rice, a heating means 2 for heating the pot 1, and a circuit board 3 on which an electronic circuit is mounted are provided inside the cooker body. Is stored.

2, the first power supply circuit 4 steps down the commercial power supply 6 and outputs a signal corresponding to the output voltage of the first power supply circuit 4 (hereinafter referred to as VCC) (output voltage detection means). A predetermined DC voltage is supplied to the drive circuit 7 and the second power supply circuit 8 for driving the heating means 2 by a signal from the diode 4a, the resistor 4b, the electrolytic capacitor 4c, the power supply IC 4d, the coil 4e, the freewheeling diode 4f, It is constituted by an electrolytic capacitor 4g. The anode of the diode 4a is connected to the commercial power supply 6, and the cathode is connected to the anode terminal of the electrolytic capacitor 4c and the input terminal of the power supply IC 4d via the resistor 4b. The anode terminal of the electrolytic capacitor 4c is connected to GND. The coil 4e and the cathode of the reflux diode 4f are connected to the output terminal of the power supply IC 4d. The output terminal of the power supply IC 4d is connected to the anode terminal of the electrolytic capacitor 4g via the coil 4e. Both the anode of the return diode 4f and the cathode terminal of the electrolytic capacitor 4g are connected to GND.

  The first power supply circuit 4 configured as described above half-wave rectifies the commercial power supply 6 by the diode 4a and the resistor 4b, and inputs the DC voltage smoothed by the electrolytic capacitor 4c to the power supply IC 4d. The power supply IC 4d is an internal switching element. Is oscillated, converted into a DC voltage by the coil 4e, the return diode 4f, and the electrolytic capacitor 4g and output.

  The feedback circuit 5 includes a photocoupler 5a and a Zener diode 5d which is a voltage setting unit connected to the light emitting diode 5b in the photocoupler 5a. When VCC exceeds the voltage obtained by adding the forward voltage VF of the light emitting diode 5b to the Zener voltage VZ1 of the Zener diode 5d, the phototransistor 5c in the photocoupler 5a becomes conductive, and the detection signal of the feedback circuit 5 is output. The power supply IC 4d receives the signal from the feedback circuit 5 and stops the oscillation of the internal switching element. Therefore, the output voltage VCC of the first power supply circuit 4 is a voltage at which the phototransistor 5c in the photocoupler 5a becomes conductive and the detection signal of the feedback circuit 5 is output, and the Zener diode 5d operates as a voltage setting unit. VCC at the time of being set to a first voltage setting value (hereinafter referred to as V1, for example, 20V). The second power supply circuit 8 steps down VCC and outputs a predetermined voltage (hereinafter referred to as VDD, for example, 5 V).

  The output voltage switching means 9 is for switching the output voltage of the first power supply circuit 4 from V1 and V1 to a second voltage setting value (hereinafter referred to as V2; for example, 10V) lower than that, a resistor 9a, a Zener diode 9b, a transistor 9c, a resistor 9d, and a resistor 9e. The Zener diode 9b has a Zener voltage smaller than that of the Zener diode 5d, and the cathode of the Zener diode 9b is connected to the cathode of the Zener diode 5d through a resistor 9a. The anode of the Zener diode 9b is connected to the emitter of the transistor 9c. The emitter of the transistor 9c is connected to the base of the transistor 9c through the resistor 9d and also to GND. Since the transistor 9c is operated by the control means 10, the base is connected to the control means 10 via the resistor 9e.

  When the transistor 9c is off, no current flows through the resistor 9a and the Zener diode 9b, so that the voltage setting unit of the feedback circuit 5 is configured by only the Zener diode 5d, and VCC at this time is V1. . On the other hand, when the transistor 9c is on, a current can flow through the resistor 9a and the Zener diode 9b. Since the Zener diode 9b having a Zener voltage smaller than the Zener diode 5d is used, even if VCC is lower than V1 and no current flows through the Zener diode 5d, VCC is applied to the Zener diode 9b. When the voltage VZ2 added with the voltage drop exceeds the voltage obtained by adding the forward voltage VF of the light emitting diode 5b, the phototransistor 5c in the photocoupler 5a becomes conductive, and the detection signal of the feedback circuit 5 is output. Therefore, when the transistor 9c is on, the Zener diode 9b is operating as a voltage setting unit. VCC when the Zener diode 9b is operating is a second voltage setting value (for example, 10V, hereinafter V2).

  The resistor 9a is a resistor for preventing the current exceeding the rated current from flowing through the Zener diode 9b immediately after the set value of the output voltage of the first power supply circuit 4 is switched from V1 to V2.

  The control means 10 is supplied with power from the second power supply circuit 8, and based on a signal from the operation means 11 for the user to operate the device, the drive circuit 7, the output voltage switching means 9, the display means 12, and the notification means 13 To output a signal. The display means 12 is for displaying and notifying the user of the state of the device. The informing means 13 is for informing the user of the state of the device by a buzzer sound or voice and operates by receiving power supply from the first power supply circuit 4, but VCC is V1 as in the drive circuit 7. It operates normally, but does not operate normally when VCC is V2.

  The voltage switching output means 10a is in the control means 10 and has a function of outputting a signal for switching VCC between V1 and V2 to the transistor 9c according to the state of the device. The time measuring means 10b is in the control means 10 and measures the elapsed time after switching VCC from V2 to V1. The voltage switching output means until the time measured by the time measuring means 10b reaches a predetermined time or more. 10a cannot switch VCC from V1 to V2.

  The first power supply circuit 4, the feedback circuit 5, the drive circuit 7, the second power supply circuit 8, the output voltage switching means 9, the control means 10, the operation means 11, and the display means 12 are all mounted on the circuit board 3. Yes.

  About the cooking appliance comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

The drive circuit 7 and the notification unit 13 operate by receiving power supply from the first power supply circuit 4, but do not operate normally when VCC is V2. Therefore, since it is necessary to operate the drive circuit 7 that drives the heating means 2 when the heating sequence is being executed, it is necessary to set VCC to V1. Therefore, during execution of the heating sequence, the control means 10 outputs a signal for turning off the transistor 9c from the voltage switching output means 10a. During the standby period when the heating sequence is not being executed, the heating means 2 is not driven, so there is no need to operate the drive circuit 7 and VCC need not be set to V1. Therefore, VCC is set to V2 lower than V1, current consumption in the drive circuit 7 and the second power supply circuit 8 is suppressed, and power consumption of the entire device is reduced. However, when the user operates the operation unit 11 even during standby, the control unit 10 may cause the notification unit 13 to operate in order to notify the user that an operation on the operation unit 11 has been accepted. Therefore, when the operating means 11 is operated while VCC is V2 during standby, it is necessary to set VCC to V1. When VCC switches from V1 to V2 lower than V1, a large current flows through the light emitting diode 5b in the photocoupler 5a of the feedback circuit 5. Accordingly, the more frequently the operation means 11 is operated during standby, the more frequently the VCC is changed from V1 to V2, and the part deterioration is further increased accordingly.

  In order to prevent such component deterioration, the control means 10 is provided with a time measuring means 10b. The time measuring means 10b measures the elapsed time after the VCC is switched from V2 to V1, and the time keeping time of the time measuring means 10b is predetermined. The control means 10 does not output a signal for setting VCC to V2 to the output voltage switching means 9 until time T is reached.

  This operation will be described with reference to FIG. In step 301, this step 301 is repeated until VCC becomes V1. When VCC becomes V1 in step 301, the process proceeds to step 302. In step 302, a V2 prohibition flag is set to prohibit the control means 10 from outputting a signal for setting VCC to V2. As long as the V2 prohibition flag is set, the control means 10 does not output a signal for setting VCC to V2. In the subsequent step 303, the elapsed time t is initialized in order to start measuring the elapsed time after VCC becomes V1 by the time measuring means 10b. In step 304, the elapsed time t is added. It is determined in step 305 whether t is a predetermined time T (for example, 30 seconds) or longer, and steps 304 and 305 are repeated while t is less than the predetermined time T. When t is equal to or longer than the predetermined time T, the process proceeds from step 305 to step 306. After the V2 prohibition flag is cleared in step 306, the process proceeds to step 307. In step 307, it is confirmed whether VCC is V2. This step 307 is repeated until VCC becomes V2, and when VCC becomes V2, the process returns to step 301.

  As described above, in the present embodiment, the control means 10 includes the time measuring means 10b for measuring the elapsed time since the switching of VCC from V2 to V1, and the control means 10 measures the time of the time measuring means 10b. It is assumed that a signal for changing VCC from V1 to V2 is not output to the output voltage switching means 9 until the time exceeds the predetermined time T. As a result, when VCC is switched from V1 to V2 lower than V1, the frequency of a large current flowing through the light emitting diode 5b in the photocoupler 5a of the feedback circuit 5 can be reduced, thereby preventing deterioration of the components of the photocoupler 5a. And the reliability of the device can be improved.

  In this embodiment, V1 is set to 20V and V2 is set to 10V. However, it is not particularly limited to this voltage, and V2 may be a voltage lower than V1.

  Further, in the present embodiment, the predetermined time T is set to 30 seconds, but it is not particularly necessary to limit T to 30 seconds.

  In this embodiment, a Zener diode is used as the voltage setting unit. However, a shunt regulator IC, another power supply IC, or the like may be used.

  In addition, although the VCC output of this embodiment is two types of V1 and V2, it is not particularly limited to two types, and can be applied to a power supply circuit that switches output voltages to a plurality.

  As described above, the cooking appliance according to the present invention can reduce the power consumption in the standby state and provide a highly reliable cooking appliance, so that the household using other commercial power sources as well as the cooking appliance can be provided. Applicable to electrical appliances.

DESCRIPTION OF SYMBOLS 1 Pan 2 Heating means 3 Circuit board 4 1st power supply circuit 4a Diode 4b Resistance 4c Electrolytic capacitor 4d Power supply IC
4e coil 4f freewheeling diode 4g electrolytic capacitor 5 feedback circuit (output voltage detection means)
5a Photocoupler 5b Light emitting diode 5c Phototransistor 5d Zener diode 6 Commercial power supply 7 Drive circuit 8 Second power supply circuit 9 Output voltage switching means 9a Resistor 9b Zener diode 9c Transistor 9d Resistor 9e Resistance 10 Control means 10a Voltage switching output means 10b Time measuring means 11 Operation means 12 Display means 13 Notification means

Claims (1)

A first power supply circuit for converting the electric power supplied from the commercial power supply to a predetermined DC voltage by the output voltage detection hand stage or these signals to output a signal corresponding to the input voltage, the output of the first power supply circuit Output voltage switching means for switching the voltage between a first voltage setting value and a second voltage setting value lower than the first voltage setting value; and an output voltage of the first power supply circuit from the second voltage setting value. Timing means for measuring an elapsed time since switching to the first voltage set value, and the output voltage switching means outputs the output of the first power supply circuit until the time measured by the time measuring means reaches a predetermined time or more. A cooking appliance in which a voltage cannot be switched from the first voltage setting value to the second voltage setting value.