JP5605086B2 - 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 household appliances, it is an important issue to reduce power consumption, and a technology for reducing power consumption when equipment is not in operation, so-called standby power has been proposed. .

  Conventionally, this type of cooking appliance includes a first power supply circuit that supplies a power supply current to the heating means, and an output voltage switching means that switches the output voltage of the first power supply circuit. In a standby state in which the operation is not executed, the setting value of the output voltage of the first power supply circuit is switched from the first voltage setting value to the second voltage setting value set lower than that (for example, Patent Document 1).

  FIG. 3 shows a circuit diagram in which a conventional cooking appliance described in Patent Document 1 is partially blocked. As shown in FIG. 3, the commercial power supply 41, the heating means 20, the drive circuit 70, the control unit 80, the first power supply circuit 12, the second power supply circuit 13, and the output voltage switching means 14 It is configured.

  As shown in FIG. 3, the first power supply circuit 12 steps down the commercial power supply 41 and supplies a DC voltage to the drive circuit 70 and the second power supply circuit 13 that drive the heating means 20 that heats the food. The device includes a diode 121, a resistor 122, an electrolytic capacitor 123, a power supply IC 124, a coil 125, a free wheeling diode 126, and an electrolytic capacitor 127.

  The DC voltage smoothed by the electrolytic capacitor 123 is input to the power supply IC 124 by half-wave rectifying the input from the commercial power supply 41 with the diode 121 and the resistor 122. The power supply IC 124 oscillates the internal switching element until there is an output of the feedback circuit composed of the Zener diode 128 and the photocoupler 129, and converts the input voltage into a DC voltage by the coil 125, the freewheeling diode 126, and the electrolytic capacitor 127, and outputs it. To do.

  The output of the feedback circuit is when the phototransistor 129 built-in phototransistor 129a is turned on, and the photocoupler 129 built-in phototransistor 129a is turned on when the output voltage of the first power supply circuit 12 is the zener diode 128. And the zener diode 141 and the first voltage set value defined by the forward voltage of the photocoupler 129 built-in light emitting diode 129b.

  Therefore, the output voltage of the first power supply circuit 12 is defined by the Zener diode 128, the Zener diode 141, and the forward voltage of the photocoupler 129 built-in light emitting diode 129b.

  Next, the output voltage switching unit 14 sets the set value of the output voltage of the first power supply circuit 12 to the first voltage set value (for example, 20V) and the second voltage set lower than the first voltage set value. This is switched to a set value (for example, 10 V), and is constituted by a Zener diode 141, a transistor 142, a resistor 143, and a resistor 145.

Since the Zener diode 128 and the Zener diode 141 are connected in series when the transistor 142 of the output voltage switching means 14 is off, the output voltage of the first power supply circuit 12 is the Zener diode 128 and the Zener diode 141. And the first voltage setting value (for example, 20 V) defined by the forward voltage of the light-emitting diode 129b with a built-in photocoupler 129.

  When the transistor 142 of the output voltage switching unit 14 is on, the Zener diode 141 is short-circuited by the transistor 142. At this time, the output voltage of the first power supply circuit 12 becomes a second voltage setting value (for example, 10 V) defined by the forward voltage of the Zener diode 128 and the light-emitting diode 129b with the built-in photocoupler 129. The on / off state of the transistor 142 is controlled by a signal output from the control unit 80.

  Immediately after the set value of the output voltage of the first power supply circuit 12 is switched from the first voltage set value (for example, 20 V) to the second voltage set value (for example, 10 V), the voltage across the electrolytic capacitor 127 is the first voltage set value. Since it is a voltage setting value (for example, 20V), an overcurrent may flow through the Zener diode 128 having a rated voltage lower than the first voltage setting value (for example, 20V). For this reason, the resistor 143 is inserted between the cathode of the Zener diode 141 and the collector of the transistor 142 to prevent an overcurrent from flowing through the Zener diode 128.

  The second power supply circuit 13 forms a step-down constant voltage circuit by the transistor 131, the resistor 132, the Zener diode 133, and the electrolytic capacitor 134, and steps down the DC voltage supplied from the first power supply circuit 12. DC voltage (for example, 5 V) is applied to the operation unit 90, the drive circuit 70 that drives the heating unit 20 according to a predetermined cooking sequence based on the input from the operation unit 90, the control unit 80 that drives the output voltage switching unit 14, and the like. Supply.

  As described above, the cooking appliance using the conventional commercial power supply uses the output voltage switching means 14 to set the output voltage setting value of the first power supply circuit 12 lower than the first voltage setting value. When the output voltage of the first power supply circuit 12 is the second output set value, the first power supply circuit 12 such as the drive circuit 70 or the second power supply circuit 13 is configured. Since the current consumed by the load is reduced, the power consumption as a device can be suppressed.

JP 2006-156147 A

  However, the conventional configuration has a problem that it is necessary to add components for defining two types of reference voltages in order to lower the output voltage of the first power supply circuit.

  Further, as the output voltage of the first power supply circuit decreases, the current flowing through the second power supply circuit decreases, so the output voltage of the second power supply circuit also decreases, but the output voltage of the first power supply circuit decreases. If the output power is too high, the output stability of the second power supply circuit is impaired, so that a sufficient current must flow through the second power supply circuit. For this reason, the second voltage setting value of the first power supply circuit is It is necessary to take a value with a sufficient margin with respect to the output voltage of the power supply circuit 2, which hinders further reduction in power consumption of the device.

  This invention solves the said conventional subject, and aims at providing the cooking appliance with little power consumption, without adding the reference voltage components.

In order to solve the above-described conventional problems, a cooking appliance of the present invention converts a power supplied from a commercial power source into a DC voltage and outputs the first power circuit, and an output voltage of the first power circuit. An output voltage detection unit for detecting, a first reference unit for setting the output voltage of the first power supply circuit to a first voltage set value, and a DC voltage by stepping down the output voltage of the first power supply circuit; A second power supply circuit that outputs, a second reference section that defines an output reference voltage of the second power supply circuit, and an output voltage of the first power supply circuit that is higher than the second reference section. when provided with an output voltage switching means for the second voltage set value lower than the voltage setting value, wherein the first power supply circuit outputs the second voltage setting value, the output voltage detecting section There is connected to the second reference portion through said output voltage switching means, and said second It is from the power supply circuit that is to have a power supply circuit configured to output voltage switching means so that to supply current to the second reference portion through the output voltage detection unit and the output voltage switching means.

Thus, the second reference unit can define not only the second power supply circuit but also the reference voltage of the first power supply circuit, and the output voltage of the first power supply circuit can be obtained without adding a reference voltage component. Can be reduced, power consumption in the standby state can be reduced, and a cooking appliance with low power consumption can be provided. In addition, when the first power supply circuit is outputting the second voltage setting value, a sufficient current can be passed through the second reference portion that defines the output reference voltage of the second power supply circuit. The output voltage of the power supply circuit can be lowered.

  Moreover, the cooking appliance of the present invention has a power supply circuit in which a resistor is connected in parallel with the light-emitting diode of the photocoupler provided in the output voltage detection unit, so that the first power supply circuit outputs the second voltage set value. Even when the power supply circuit is in a standby state, a sufficient current can be passed through the second reference section that defines the output reference voltage of the second power supply circuit, and the output voltage of the first power supply circuit can be further reduced. Power consumption can be reduced, and cooking equipment with less power consumption can be provided.

The cooking appliance of the present invention can reduce the output voltage of the first power supply circuit without adding a reference voltage component, can reduce power consumption in a standby state, and provides a cooking appliance with low power consumption. Can contribute to energy saving. In addition, when the first power supply circuit is outputting the second voltage setting value, a sufficient current can be passed through the second reference portion that defines the output reference voltage of the second power supply circuit. The output voltage of the power supply circuit can be lowered.

The circuit diagram which made the cooking appliance in Embodiment 1 of this invention into the partial block The circuit diagram which made the cooking appliance in Embodiment 2 of this invention into the partial block 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 DC voltage and outputs the output, an output voltage detection unit that detects an output voltage of the first power supply circuit, and the first power supply circuit A first reference section for setting the output voltage of the power supply circuit to a first voltage set value; a second power supply circuit for stepping down the output voltage of the first power supply circuit and outputting a DC voltage; A second reference part for defining an output reference voltage of the power supply circuit, and a second voltage set value for making the output voltage of the first power supply circuit higher than the second reference part and lower than the first voltage set value Output voltage switching means, and when the first power supply circuit outputs the second voltage set value , the output voltage detector is configured to output the second voltage via the output voltage switching means . It is connected to the reference unit, and the output voltage detection unit and the front from the first power supply circuit By having a power supply circuit constituting said output voltage switching means so that to supply current to the second reference portion via the output voltage switching means, the second reference part is not only the second power supply circuit, the The reference voltage of one power supply circuit can also be defined, the output voltage of the first power supply circuit can be lowered without newly adding a reference voltage component, and the power consumption in the standby state can be reduced. A cooking appliance with low power consumption can be provided. In addition, when the first power supply circuit is outputting the second voltage setting value, a sufficient current can be passed through the second reference portion that defines the output reference voltage of the second power supply circuit. The output voltage of the power supply circuit can be lowered.

According to a second 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 DC voltage and outputs the output, an output voltage detection unit that detects an output voltage of the first power supply circuit, and the first A first reference unit for setting the output voltage of the first power supply circuit to a first voltage setting value, a second power supply circuit for stepping down the output voltage of the first power supply circuit and outputting a DC voltage, and the second A second reference part that defines an output reference voltage of the second power supply circuit, and a second voltage set value that causes the output voltage of the first power supply circuit to be higher than the second reference part and lower than the first voltage set value. Output voltage switching means, and when the first power supply circuit outputs the second voltage set value, the output voltage detection unit is connected to the second reference unit. with configuring the output voltage switching means, the photo-coupler in the output voltage detecting section In addition, the power supply circuit having a resistor connected in parallel with the light-emitting diode of the photocoupler allows the second power supply circuit even when the first power supply circuit outputs the second voltage set value. A sufficient current can be passed through the second reference section that defines the output reference voltage of the first power supply circuit, so that the first voltage setting value or the second voltage setting value is the first voltage setting value. The power supply circuit 2 can output stably, the output voltage of the first power supply circuit can be further lowered, power consumption in the standby state can be reduced, and a cooking device with lower power consumption can be provided. .

  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 shows a partially block circuit diagram of a cooking appliance according to the first embodiment of the present invention.

  In FIG. 1, a first power supply circuit 1 supplies a DC voltage to a drive circuit 4 and a second power supply circuit 5 that drive a heating means 3 that steps down a commercial power supply 2 and heats an object to be cooked. A diode 1a, a resistor 1b, an electrolytic capacitor 1c, a power supply IC 1d, a coil 1e, a freewheeling diode 1f, and an electrolytic capacitor 1g are included.

  The anode of the diode 1a is connected to the commercial power source 2, and the cathode is connected to the anode terminal of the electrolytic capacitor 1c and the input terminal of the power source IC 1d via the resistor 1b. The cathode terminal of the electrolytic capacitor 1c is connected (grounded) to GND.

  The output terminal of the power supply IC 1d is connected to the coil 1e and the cathode of the reflux diode 1f. The output terminal of the power supply IC 1d is connected to the anode terminal of the electrolytic capacitor 1g via the coil 1e. Both the anode of the return diode 1f and the cathode terminal of the electrolytic capacitor 1g are connected (grounded) to GND.

  The first power supply circuit 1 configured as described above half-wave rectifies the input from the commercial power supply 2 by the diode 1a and the resistor 1b, and inputs the DC voltage smoothed by the electrolytic capacitor 1c to the power supply IC1d. Oscillates the internal switching element, converts it into a DC voltage by the coil 1e, the freewheeling diode 1f, and the electrolytic capacitor 1g and outputs it.

  The output voltage detector 6 detects the output voltage of the first power supply circuit 1 and is composed of a photocoupler. The collector of the phototransistor 6a in the photocoupler is connected to the control terminal of the power supply IC1d, and the emitter Is connected to the output terminal. When the built-in phototransistor 6a is turned on, the power supply IC 1d stops the oscillation of the internal switching element.

  On the other hand, the built-in light emitting diode 6b of the photocoupler has an anode connected to the output terminal of the power supply IC 1d and a cathode connected to the cathode of the Zener diode 7a.

  The anode of the Zener diode 7a is connected (grounded) to GND. The Zener diode 7a is a first reference unit 7 for setting the output voltage of the first power supply circuit 1 to a first voltage setting value (for example, 20V).

  The second power supply circuit 5 steps down the DC voltage supplied from the first power supply circuit 1 and drives the heating means 3 according to a predetermined cooking sequence based on the operation unit 8 or an input from the operation unit 8. DC voltage is supplied to the control unit 9 and the like. The NPN transistor 5a, the resistor 5b, the Zener diode 5c, and the electrolytic capacitor 5d form a step-down constant voltage circuit, which is substantially the same circuit configuration as the second power supply circuit 13 in the conventional cooking appliance shown in FIG. .

  The collector of the NPN transistor 5 a is connected to the anode terminal of the electrolytic capacitor 1 g that is the output of the first power supply circuit 1.

The base of the NPN transistor 5a is connected to the collector of the NPN transistor 5a through the resistor 5b, and is also connected to the cathode of the Zener diode 5c. The anode of the Zener diode 5c is connected (grounded) to GND.

  The emitter of the NPN transistor 5a is connected to the anode terminal of the electrolytic capacitor 5d, and the cathode terminal of the electrolytic capacitor 5d is connected (grounded) to GND.

  In the second power supply circuit 5 configured as described above, the emitter of the NPN transistor 5a is an output unit, and the Zener diode 5c defines the output reference voltage (for example, 5V) of the second power supply circuit 5. Part.

  The output voltage switching means 10 switches the output voltage of the first power supply circuit 1 between a first voltage set value and a second voltage set value (for example, 7 V) lower than the first voltage set value. The PNP transistor 10a, the NPN transistor 10b, and resistors 10c to 10g are included.

  The emitter of the PNP transistor 10a is connected to the cathode of the built-in light-emitting diode 6b of the photocoupler via the resistor 10c, and the collector of the PNP transistor 10a is connected to the cathode of the Zener diode 5c. The base of the PNP transistor 10a is connected to the collector of the NPN transistor 10b through the resistor 10e, and is also connected to the emitter of the PNP transistor 10a through the resistor 10d.

  The emitter of the NPN transistor 10b is connected to the base of the NPN transistor 10b via the resistor 10f and also connected (grounded) to GND. The base of the NPN transistor 10b is connected to the control unit 9 via a resistor 10g.

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

  When a signal for turning off the NPN transistor 10b is output from the control unit 9, the PNP transistor 10a is turned off. At this time, the Zener diode 7a which is the first reference portion 7 is only connected to the built-in light emitting diode 6b of the photocoupler.

  As a result, the output voltage of the first power supply circuit 1 becomes larger than the first voltage set value defined by the forward voltage of the light-emitting diode 6b built in the photocoupler and the Zener diode 7a, and the phototransistor built-in phototransistor 6a. Will be conducted. Therefore, the output voltage of the first power supply circuit 1 becomes the first voltage setting value defined by the forward voltage of the built-in light emitting diode 6b of the photocoupler and the Zener diode 7a.

  On the other hand, when a signal for turning on the NPN transistor 10b is output from the control unit 9, the PNP transistor 10a is also turned on. At this time, the Zener diode 5c, which is the first reference portion 7, and the Zener diode 5c are connected to the built-in light emitting diode 6b of the photocoupler via the resistor 10c. (The collector-emitter voltage of the PNP transistor 10a is assumed to be negligibly small).

  The Zener diode 5c is a second reference part that defines an output reference voltage (for example, 5V) of the second power supply circuit 5, and uses the output voltage of the first power supply circuit 1 as a first voltage setting value (for example, 20V). Therefore, it is sufficiently smaller than the Zener diode 7a of the first reference portion 7 for this purpose.

Therefore, when the PNP transistor 10a is on, the output voltage of the first power supply circuit 1 is the first voltage set value defined by the forward voltage of the built-in light emitting diode 6b of the photocoupler and the Zener diode 7a. Even if it is lower than (for example, 20V), if the forward voltage of the built-in light-emitting diode 6b of the photocoupler and the voltage defined by the resistor 10c and the Zener diode 5c are higher, current flows through the built-in light-emitting diode 6b and the built-in phototransistor 6a. Is conducted.

  Therefore, when the PNP transistor 10a is on, the output voltage of the first power supply circuit 1 can be set to a voltage lower than the first voltage set value. The output voltage of the first power supply circuit 1 when the PNP transistor 10a is on is the second voltage setting value.

  Immediately after the set value of the output voltage of the first power supply circuit 1 is switched from the first voltage set value to the second voltage set value, the voltage across the electrolytic capacitor 1g remains at the first voltage set value. . For this reason, an overcurrent flows through the Zener diode 5c having a rated voltage lower than the first voltage setting value, which may cause a failure. In order to prevent a failure due to this overcurrent, a resistor 10c is connected between the built-in light emitting diode 6b and the emitter of the PNP transistor 10a.

  As described above, in the present embodiment, when the first power supply circuit 1 outputs the second voltage set value, the output voltage detection unit 6 is connected to the Zener diode 5c that is the second reference unit. By configuring the output voltage switching means 10 as described above, in order to set the output voltage of the first power supply circuit 1 to a second voltage set value lower than the first voltage set value, the output of the second power supply circuit 5 The second reference portion Zener diode 5c for defining the reference voltage can be used, and the second output voltage of the first power supply circuit is lower than the first voltage setting value without newly adding a reference voltage component. Voltage set value.

  When the output voltage of the first power supply circuit 1 is the second voltage setting value, the current consumed by the load of the first power supply circuit 1 such as the drive circuit 4 and the second power supply circuit 5 is also reduced. The power consumption as a device can be suppressed, the power consumption in the standby state can be reduced, and a cooking device with low power consumption can be provided.

  In the present embodiment, the first reference portion and the second reference portion are configured by Zener diodes. However, they may not be particularly Zener diodes, and may be configured by, for example, a shunt regulator IC.

  Further, in the present embodiment, the Zener diode necessary for switching the output voltage of the first power supply circuit can be reduced as compared with the conventional case shown in FIG. Since it is not so complicated and the components are relatively inexpensive parts, it is possible to reduce expensive Zener diodes and to provide products with excellent energy savings at a lower price.

(Embodiment 2)
FIG. 2 shows a partial block circuit diagram of the cooking appliance according to the second embodiment of the present invention.

  As shown in FIG. 2, a resistor 11a having a resistance value R11a is connected in parallel with the built-in light emitting diode 6b of the photocoupler.

  When the built-in phototransistor 6a conducts and the oscillation of the power supply IC 1d stops, the current flowing through the built-in light-emitting diode 6b of the photocoupler is If, and the voltage across the built-in light-emitting diode 6b when the current If flows through the built-in light-emitting diode 6b And

Further, when the first power supply circuit 1 outputs the second voltage set value by the output voltage switching means 10, the output voltage switching means 10 connects the base of the NPN transistor 5a and the Zener diode 5c which is the second reference portion. The current flowing into the point is I10.

  Other configurations are the same as those of the first embodiment, and the same reference numerals are given and description thereof is omitted.

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

  When the resistor 11a is present, I10 increases by Vf / R11a when the resistor 11a is present. Therefore, even if the current flowing through the resistor 5b is reduced by this increment Vf / R11a, the base current and the zener of the NPN transistor 5a are reduced. The current flowing through the diode 5c is the same as when there is no resistor 11a, and there is no influence on the output voltage of the Zener diode 5c or the output voltage of the second power supply circuit 5.

  Therefore, when the resistance value R5b of the resistor 5b is used, the voltage drop at the resistor 5b can be reduced by Vf / R11a × R5b. That is, the presence of the resistor 11a makes it possible to further lower the second voltage set value by Vf / R11a × R5b.

  As described above, in the present embodiment, the first power supply circuit 1 is connected to the second voltage setting value by connecting the resistor 11a in parallel with the built-in light emitting diode 6b of the photocoupler that is the output voltage detection unit 6. Even when the second power supply circuit 5 outputs a sufficient current to the zener diode 5c of the second reference section that defines the output reference voltage of the second power supply circuit 5, the second voltage setting value of the first power supply circuit 1 Can be made lower. As a result, power consumption in the drive circuit 4 that is the load of the first power supply circuit 1 can be suppressed.

  In the present embodiment, the first reference portion and the second reference portion are configured by Zener diodes. However, the first reference portion and the second reference portion are not particularly limited to Zener diodes, and may be configured by, for example, a shunt regulator IC.

  As described above, the cooking appliance according to the present invention can reduce the output voltage of the first power supply circuit without adding a reference voltage component, can reduce power consumption in a standby state, and can contribute to energy saving. Therefore, it can also be applied to other uses such as a heating apparatus having a standby state and heating means.

DESCRIPTION OF SYMBOLS 1 1st power supply circuit 1a Diode 1b Resistance 1c Electrolytic capacitor 1d Power supply IC
1e coil 1f freewheeling diode 1g electrolytic capacitor 2 commercial power supply 3 heating means 4 drive circuit 5 second power supply circuit 5a NPN transistor 5b resistor 5c Zener diode (second reference part)
5d Electrolytic capacitor 6 Output voltage detection unit 6a Built-in phototransistor 6b Built-in light emitting diode 7 First reference unit 7a Zener diode 8 Operation unit 9 Control unit 10 Output voltage switching means 10a PNP transistor 10b NPN transistor 10c, 10d, 10e, 10f, 10g Resistance 11a Resistance

Claims (2)

A first power supply circuit that converts electric power supplied from a commercial power supply into a DC voltage and outputs the output, an output voltage detector that detects an output voltage of the first power supply circuit, and an output voltage of the first power supply circuit Is a first reference section for setting the first voltage setting value, a second power supply circuit that steps down the output voltage of the first power supply circuit and outputs a DC voltage, and an output of the second power supply circuit A second reference section that defines a reference voltage, and an output for setting the output voltage of the first power supply circuit to a second voltage set value that is higher than the second reference section and lower than the first voltage set value. Voltage switching means, and when the first power supply circuit outputs the second voltage set value , the output voltage detection section is connected to the second reference section via the output voltage switching means. And the output voltage detector and the output voltage switch from the first power supply circuit. Cooking device having a power supply circuit constituting said output voltage switching means so that to supply current to the second reference section through the unit. A first power supply circuit that converts electric power supplied from a commercial power supply into a DC voltage and outputs the output, an output voltage detector that detects an output voltage of the first power supply circuit, and an output voltage of the first power supply circuit Is a first reference section for setting the first voltage setting value, a second power supply circuit that steps down the output voltage of the first power supply circuit and outputs a DC voltage, and an output of the second power supply circuit A second reference section that defines a reference voltage, and an output voltage for setting the output voltage of the first power supply circuit to a second voltage set value that is higher than the second reference section and lower than the first voltage set value. Switching means, and the output voltage switching means is configured such that the output voltage detection unit is connected to the second reference unit when the first power supply circuit outputs the second voltage set value. as well as, wherein the output voltage detection unit comprises a photocoupler, the full Photocoupler light-emitting diode and physical equipment tone that having a power supply circuit by connecting a resistor in parallel.

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