JP5304253B2 - Cooker - Google Patents

Description

  The purpose is to continue the program operation without losing the progress of the program by increasing the time until the microcomputer is reset without increasing the capacity of the capacitor in response to the AC power failure.

  A conventional power failure detection apparatus will be described with reference to FIG. Reference numeral 1 denotes an AC power source which is a commercial power source. A diode 2 and a capacitor 3 are connected in series at both ends of the commercial power source, and a DC voltage is obtained from both ends of the capacitor 3. A switching power supply 4 is connected with a DC voltage across the capacitor 3 as an input, and the switching power supply 4 has an output capacitor 4a. The AC monitoring device 5 includes a circuit in which a diode 5a, a resistor 5b, and a resistor 5c are sequentially connected in series to both ends of the AC power source 1, and a capacitor 5d is connected in parallel to the resistor 5c. Information on the voltage of the AC power supply is output from the connection point between the resistor 5b and the resistor 5c. The cathode of the constant voltage diode 6a is connected to the output of the AC monitoring device 5, and the base of the transistor 6b is connected to the anode of the constant voltage diode 6a. The resistor 6c and the base of the transistor 6d are connected to the collector of the transistor 6b. The other end of the resistor 6 c is connected to the output of the output capacitor 4 a of the switching power supply 4, and the emitters of the transistors 6 b and 6 d are connected to the negative terminal of the switching power supply 4. The constant voltage diode 6a, the transistor 6b, the resistor 6c, and the transistor 6d constitute a zero volt erase circuit 6.

  In the zero volt circuit 7, a diode 7a, a resistor 7b, and a resistor 7c are connected in series to both ends of the AC power source 1, and a collector of the transistor 6d and a base of the transistor 7d are connected to a connection point between the resistor 7b and the resistor 7c. The collector of the transistor 7d is connected to the resistor 7e, the other end of the resistor 7e is connected to the output of the switching power supply 4, and the emitter of the transistor 7d is connected to the minus terminal.

  A microcomputer (hereinafter referred to as a microcomputer) 8 operates using the output of the output capacitor 4 a of the switching power supply 4 as a power supply, and the collector of the transistor 7 d of the zero volt circuit 7 is connected to the input terminal A. The output terminal B of the microcomputer 8 is connected to a relay (not shown) connected to the load group 9. The load group 9 is driven by the switching power supply 4 or the AC power supply 1, and the microcomputer 8 controls the relay on / off. As a result, the drive is controlled.

  The operation of the above configuration will be described below.

  When the rated AC voltage is supplied from the AC power source 1, the AC monitoring device 5 is connected to the diode 5a by a resistor 5b, a resistor 5c, and a capacitor 5d during a half cycle of a sine wave in which a forward current flows. A DC voltage is output to the capacitor 5d according to the voltage. When the voltage of the AC power supply 1 is normal, the voltage of the capacitor 5d becomes higher than the sum of the Zener voltage of the constant voltage diode 6a of the zero-volt erasing circuit 6 and the base-emitter on voltage of the transistor 6b. As a result, the transistor 6b is turned on and collector current flows, so that current flows through the resistor 6c, the voltage between the collector and emitter of the transistor 6d becomes almost zero, and the transistor 6d is turned off. Thereby, the collector of the transistor 6d has no effect on the transistor 7d of the zero volt circuit 7.

  At this time, the zero volt circuit 7 ignores the forward voltage of the diode 7a, and the alternating voltage is applied to the resistors 7a and 7b in the half cycle of the alternating current in which the forward current flows in the diode 7a. When the base-emitter on-voltage, that is, about 0.6V is reached, the transistor 7d is turned on and the collector becomes 0V. This voltage will be referred to as low. On the other hand, in the opposite half wave, the transistor is turned off, and the collector of the transistor 7d is almost the voltage of the switching power supply. This voltage is called high. When the alternating voltage is supplied in this way, the high and low voltages are alternately input to the collector of the transistor 7d, that is, the microcomputer 8, and the microcomputer 8 detects this and the signal is present. Is running the program.

Next, when the voltage of the AC power supply 1 drops to a voltage at which the switching power supply cannot operate, the voltage of the capacitor 5d becomes lower than the sum voltage of the zener voltage of the constant voltage diode 6a and the on-voltage between the base and emitter of the transistor 6b. The transistor 6b is turned off, and the transistor 6d is turned on when a bias current is applied from the switching power supply 4 by the resistor 6c. When the transistor 6d is turned on, the collector current flows from the switching power supply 4 via the diode 7a and the resistor 7b, and the collector-emitter voltage becomes almost 0V. Thereby, the base of the transistor 7d is turned off, and the collector voltage of the transistor 7d, that is, the input voltage to the input terminal A of the microcomputer 8 becomes high. Here, the microcomputer 8 operates only when there is a signal at the input terminal A. When there is no input signal, the microcomputer 8 detects this, saves the current program operation, stops, and stops the output terminal B. Is stopped, the operation of the load group 9 is stopped, and the power consumption of the switching power supply 4 and the AC power supply 1 is reduced. When the voltage of the AC power supply 1 is supplied again before the voltage of the switching power supply 4 drops to a voltage at which the microcomputer 8 is reset, the microcomputer 8 detects this and starts the program operation from the state before the power failure. Resume. That is, when the microcomputer 8 detects that the input terminal A is high and detects that the voltage of the AC power supply 1 has decreased by a certain value, the microcomputer 8 stores and stops the program operation, and is controlled by the output terminal B of the microcomputer 8. The operation of stopping the load group 9 is performed. As a result, no power is supplied to the load group 9 using the switching power supply 4 and the AC power supply 1 as a power supply source, and the output current of the switching power supply 4 decreases. When the voltage of the AC power supply 1 drops to a voltage at which the switching power supply 4 cannot operate, the diode 2 is reverse-biased in the initial stage, and the switching operation continues due to the residual charge of the capacitor 3. When the voltage 3 decreases to a voltage at which the switching power supply 4 cannot operate, power is supplied to the load only by the output capacitor 4a of the switching power supply 4. That is, when the voltage of the AC power supply 1 decreases by a certain value, the load group 9 does not consume power as described above, so that the amount of residual charge used in the capacitor 3 decreases, and the output current of the capacitor 4a also decreases. Therefore, the time until the microcomputer 8 is reset can be made longer than when the zero volt erase circuit 6 is not provided.
JP 2006-296153 A

  In the above-described conventional configuration, when a device having a microcomputer that operates using zero volt of an AC power supply detects a power outage or power supply loss using the signal, a load that does not lose a program that is executed such as a sequence operation It is possible to stop. However, in this conventional configuration, since the zero volt output of the AC power supply is used, a power failure or a power supply drop can be detected only by the cycle of the AC power supply. A capacitor is connected to the DC power supply of the device, and it can charge a certain amount of charge, but how does the DC power supply voltage drop when a DC power is no longer output from the switching power supply due to a power failure or power supply drop? It depends on the load at that time. Therefore, there is a problem that when the load is large, the voltage of the DC power supply drops quickly, and when it is earlier than the cycle of the zero volt signal, the microcomputer may be reset.

The present invention solves the above-mentioned problem. Instead of the conventional power failure detection circuit using a zero volt signal, the heating cooker of the present invention includes a DC power source obtained from an AC power source as a commercial power source, and a DC power source. A switching power supply that supplies power to one load group, a microcomputer that drives the first load group from an output of the switching power supply, a low-voltage power supply that supplies power to the second load group, and the low-voltage power supply And a power failure detection circuit for detecting a power failure from the output voltage of the switching power supply. When the power failure detection circuit detects a power failure, the power failure detection circuit A transistor for supplying power to the second load group from the output of the low-voltage power supply is deactivated, and the microcomputer supplies power to the second load group. When it is detected that the power supply has been lost, the program operation being executed is saved, the first load group of the device is brought into a non-driven state, and the microcomputer is not reset, and the second load When it is detected that the power supply to the group has been resumed, the saved program operation is resumed, and when the DC power is not output from the switching power supply due to a power failure or power supply drop, and the load is large Although the voltage of the DC power supply drops quickly, the time until the microcomputer is reset can be extended by detecting a power failure with the output voltage of the switching power supply. Therefore, the frequency of short power failures that do not require resetting increases, and when a power failure is restored, if the reset does not take place, the program operation that is being executed at the time of power failure detection is resumed. In other words, a power failure or voltage drop is detected before the microcomputer is reset regardless of the load of the DC power supply. If the reset is not applied, the load can be stopped without losing the program being executed such as sequence operation. It is said.

In the heating cooker of the present invention, a DC current is not output from the switching power supply due to a power failure or a power supply drop, and when the load is large, the voltage of the DC power supply drops quickly, but by detecting the power failure with the output voltage of the switching power supply The time until the microcomputer is reset can be extended. Therefore, the frequency of short power failures that do not require resetting increases, and when a power failure is restored, if the reset does not take place, the program operation that is being executed at the time of power failure detection is resumed.

According to a first aspect of the present invention, a DC power source obtained from an AC power source that is a commercial power source, a switching power source that supplies power from the DC power source to a first load group, and the first load group from an output of the switching power source a low-voltage power supply for supplying power to the microcomputer and the second load group driven, the transistor for supply feeding the output of the low voltage power supply to the second load group, blackout from the output voltage of the switching power supply and a power failure detecting circuit for detecting said power failure detecting circuit and the power failure detection circuit detects the power failure, and the non-operative transistors for supplying electric power from the output of the low voltage power supply to the second load group , before Symbol microcomputer, stores the detection result executed with a program operation that power supply to the second load group has disappeared, said first load groups of devices While the driving state, the microcomputer detects that the power supply of the to the second load group is resumed without contracting reset, by resuming from the program operation saved, power failure or power supply When DC power is not output from the switching power supply due to the drop and the load is large, the voltage of the DC power supply drops quickly, but by detecting a power failure with the output voltage of the switching power supply, the time until the microcomputer is reset is extended. be able to. Therefore, the frequency of short power failures that do not require resetting increases, and when a power failure is restored, if the reset does not take place, the program operation that is being executed at the time of power failure detection is resumed.

A second invention is, in particular, in the first invention comprises a transistor for supplying a power to the first load group, when the power failure detection circuit detects the power failure, to the first load group By shutting off the power supply, it is possible to reduce the amount of residual charge used by the capacitor on the output side even when switching of the switching power supply is stopped, and the low-voltage power supply reduces the power output for the microcomputer. The time to stop can be extended. Therefore, the time until the microcomputer is reset can be extended.

A third invention is, in particular, in the first or second aspect, comprises a zero volt circuit for detecting the zero volt vicinity of the alternating current power supply, a microcomputer that operates program using the signal from the zero volt circuit, the zero volt When the microcomputer detects a power failure when the signal from the circuit is lost, the load on the output side of the switching power supply is low and the voltage is low when the load is light. Even when the speed of slowing down is slow, it is possible to detect a power outage by detecting zero volts of the AC power supply, and by combining with the detection method by the power outage detection circuit, it is possible to quickly detect a power outage regardless of the size of the load. This will increase the time it takes for the microcomputer to reset. Can.

According to a fourth aspect of the present invention, there is provided a DC power source obtained from an AC power source, a switching power source that supplies power from the DC power source to the first load group, and power from the output of the switching power source to the microcomputer and the second load group. A power failure detection circuit for detecting a power failure from an output voltage of the switching power supply; a low voltage power supply to be supplied; a transistor for supplying an output of the low voltage power supply to the second load group; When a power failure is detected, the transistor that supplies power to the second load group from the output of the low-voltage power supply is deactivated, and the microcomputer detects that power supply to the second load group is lost. , together with the load device to the non-driven state, it has the microcomputer and the external memory of the transmitting and receiving non-volatile data, the micro competent When the data is detected, the device status is written to the external memory, and even if the microcomputer is reset, the status before reset can be read from the external memory before and after the power failure. By enabling operation, even if the microcomputer is reset due to a power failure, the state before power failure can be read and operated after power failure recovery by storing the state in external memory before resetting. Is possible. In particular, when automatic cooking is performed, the process at the time of power failure can be stored, and when power is restored from the power failure, it is possible to prevent the power failure from adversely affecting cooking results by restarting cooking from the same process as before the power failure. .

A fifth invention is, in particular, in the first to fourth one of the invention, comprising a plurality of microcomputers, each of the microcomputers A heating cooker having a means for communicating with other of the microcomputer by said the microcomputer detects the power failure and sends its state to the other of said microcomputer, besides the microcomputer that has received the communication that the power failure state, the load of equipment in the non-driven state, In a cooking device with multiple microcomputers, even if the timing for detecting a power outage varies from one microcomputer to another when a power outage occurs, the microcomputer that detected the power outage early sends out power outage information to other microcomputers. All microcomputers are reset It is possible to extend the time until the hunt.

A sixth invention is particularly, in the first to fifth any one invention, comprising a plurality of microcomputers, each of the microcomputers A heating cooker having a means for communicating with other of the microcomputer , when a reset is triggered on the microcomputer, since the communication signal is cut off, it is detected that the other of said microcomputer is a power failure condition by that the non-driven state the load of the device, a plurality of In a heating cooker with a microcomputer, when the power failure occurs, the power supply voltage to drive the microcomputer is different, and even if one of the microcomputers is reset, it can be detected quickly to detect other microcomputers. Increase the time it takes for the computer to reset It can be. Especially if it is a heating cooker with a microcomputer that controls the cooking section and a microcomputer that gives instructions to the microcomputer, there is no problem before and after a power failure by preventing the microcomputer that gives the instructions from being reset. It becomes possible to continue cooking.

  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 block diagram according to the first embodiment of the present invention. A diode a22 and a capacitor a23 are connected in series at both ends of the AC power supply 21, and a DC power supply is obtained from both ends of the capacitor a23. A switching power supply 24 is connected with a DC voltage across the capacitor a23 as an input, and the switching power supply 24 has an output capacitor b25. The power failure detection circuit 26 is configured by a circuit in which a Zener diode 26 a and a resistor 26 b are connected in series to the output of the switching power supply 24. The output of the switching power supply 24 is connected to a load group a27 and a low voltage power supply 28 for outputting the power supply of the microcomputer. The low voltage power supply 28 has an output capacitor c29. Although the microcomputer 30 and the load group b31 are connected to the output of the low voltage power supply 28, the connection to the load group b31 is only when the transistor 32 is on. In addition, regarding the load group a27 and the load group b31 described here, the load group a27 is assumed to be a load that is driven at a voltage higher than a certain level by a voltage higher than the drive voltage of the microcomputer, such as a fan or a relay, and the load group b31. Is assumed to be driven at a voltage equivalent to the driving voltage of a microcomputer such as an LED or a thermistor.

  The operation of the cooking device configured as described above will be described.

  When the rated AC voltage is supplied to the switching power supply 24 by the AC power supply 21, the DC voltage across the diode a22 and the capacitor a23 is stable, and the switching power supply 24 is stable to the load group a27 and the low voltage power supply 28. DC power can be supplied. At this time, the voltage applied to the power failure detection circuit 26 is higher than the sum of the Zener voltage of the Zener diode 26a of the power failure detection circuit 26 and the base-emitter on voltage of the transistor 32, whereby the transistor 32 is turned on. Thus, the collector current flows, and the output of the low voltage power supply 28 is input to the load group b31. At this time, the microcomputer 30 detects that the transistor 32 is turned on by detecting the emitter voltage of the transistor 32, that is, that a voltage in the normal range is applied to the power failure detection circuit 26, and is not in a power failure state. Detect that.

  Next, the voltage of the AC power supply decreases to a voltage at which the switching power supply 24 cannot operate, the voltage of the output of the switching power supply 24 also decreases, and is lower than the sum of the Zener voltage of the Zener diode 26a and the base-emitter on voltage of the transistor 32. When the voltage is reached, the transistor 32 is turned off, and the output of the low voltage power supply 28 is not input to the load group 31b. At this time, the microcomputer 30 detects that the transistor 32 is not turned on by detecting the emitter voltage of the transistor 32, that is, the voltage applied to the power failure detection circuit 26 is lower than the normal state and is in a power failure state. Detect. The output from the low voltage power supply 28 is input to the microcomputer 30 and the load group b31. However, when the power failure detection circuit 26 detects a power failure, the transistor 32 is turned off and the input to the load group b31 is interrupted. Only the microcomputer 30 is connected to the output of the low voltage power source. At this time, since the load group b31 does not consume power, the amount of use of the residual charge of the capacitor c29 is reduced, and the time until the microcomputer 31 is reset can be longer than when there is no power failure detection circuit. Further, when the microcomputer 31 detects a power failure, turning off the load group a27 driven by the microcomputer 31 reduces the amount of residual charge used by the capacitors a23 and b25 until the microcomputer 31 is reset. You can extend the time.

(Embodiment 2)
FIG. 2 is a diagram showing a configuration of a heating cooker according to the second embodiment of the present invention.

  The heating cooker according to the present embodiment is different from the first embodiment in that a transistor b34 for supplying power to a load group a27 of the heating cooker and a zero volt detection circuit 35 are provided. Other parts representing the same configuration and operational effects are denoted by the same reference numerals, detailed description thereof is omitted, and different points will be mainly described.

  In the second embodiment, when the power failure detection circuit 26 detects a power failure, the transistor b34 for supplying power to the load group a27 is turned off, and the power supply to the load group a27 is shut off. The load group a27 includes a fan and a relay. In particular, the fan consumes a larger amount of electric power when driving than other loads, and therefore it is necessary to quickly turn off the load during a power failure. By adding this transistor b34, even when switching of the switching power supply 24 is stopped, the amount of residual charge in the output-side capacitor b25 can be reduced, and the low-voltage power supply 28 can reduce the power output for the microcomputer. The time to stop can be extended.

Further, the microcomputer 30 that performs a program operation using the signal from the zero volt detection circuit 35 is used, and when the signal from the zero volt detection circuit 35 is lost, the microcomputer 30 detects a power failure, thereby reducing the load a27. In other words, when the AC power supply is interrupted, such as when a large load such as a fan is not operating, the AC power supply 21 is used even when the amount of residual charge in the capacitor b25 on the output side of the switching power supply 24 is small and the voltage drop speed is slow. By detecting this zero volt, it is possible to detect a power failure, and by combining with the detection method by the power failure detection circuit 26, it is possible to quickly detect a power failure regardless of the size of the load a27. As a result, the microcomputer 30 is reset. The time until this can be extended.

(Embodiment 3)
FIG. 3 is a block diagram showing a configuration of a heating cooker according to the third embodiment of the present invention.

  The cooking device of the present embodiment has a nonvolatile memory 36 that is a nonvolatile external memory capable of transmitting and receiving data to and from the microcomputer a30, and the cooking device has a plurality of microcomputers a30 and b37. Each microcomputer a30 or b37 is different from the first embodiment only in that it has means for communicating with other microcomputers b37 or a30, and other parts that represent the same configuration and function and effect are denoted by the same reference numerals. Detailed description will be omitted, and different points will be mainly described. In the third embodiment, there are two microcomputers a30 and b37, which are the microcomputer a30 and the microcomputer b37, respectively.

  In the third embodiment, when the power failure detection circuit 26 detects a power failure and the microcomputer a30 detects a power failure from the input voltage of the load group b31, the state of the device is written to the external memory and reset to the microcomputer a30. Even in the event of a failure, the state before the reset is read from the external nonvolatile memory 36, and the state before the power failure can be maintained. Further, at the time of this power failure, the microcomputer a30 transmits to the microcomputer b37 that the power failure has occurred, and the microcomputer b37 receiving the information does not drive the load (not shown) of the equipment connected to the microcomputer b37. Put it in a state. With this configuration, it is possible to extend the time until all the microcomputers are reset.

  As described above, the heating cooker according to the present invention does not output DC current from the switching power supply due to a power failure or power supply drop, and the voltage of the DC power supply drops quickly when the load is large. Since it is possible to extend the time until the microcomputer is reset by detecting a power failure, the invention can also be applied to uses such as domestic or commercial heating cookers having a switching power supply and a microcomputer.

The block diagram which shows the induction heating cooking appliance in Embodiment 1 of this invention The block diagram which shows the induction heating cooking appliance in Embodiment 2 of this invention The block diagram which shows the induction heating cooking appliance in Embodiment 3 of this invention The block diagram which shows the induction heating cooking appliance in the prior art example of this invention

21 AC power supply 22 Diode a
23 Capacitor a
24 switching power supply 25 capacitor b
26 Power failure detection circuit 27 Load group a (first load group)
28 Low voltage power supply 29 Capacitor c
30 microcomputer 31 load group b (second load group)
32 transistor 33 cooking heater

Claims (6)

A DC power supply derived from an AC power source is a commercial power supply, a switching power supply for supplying power to the first load group from the DC power source, a microcomputer and a driving said first load groups from an output of the switching power supply a low voltage power supply for supplying power to the second load group, wherein the transistor for supplying an output of the low voltage power supply to the second load groups, and power failure detection circuit for detecting a power failure from the output voltage of the switching power supply , wherein the said failure detection circuit and the power failure detection circuit detects the power failure, said the non-operating transistor for supplying power from the output of the low voltage power supply to the second load group, before Symbol microcomputer, Save the detection result executed with a program operation that power supply to the second load group has disappeared, to said first load groups of devices to a non-driven state Together with the microcomputer, the reset is written
If it is detected that the power supply to the second load group has been resumed, the cooking device resumes from the stored program operation . Comprises a transistor for supplying a power to the first load group, when the power failure detection circuit detects the power failure, cooking according to claim 1 to cut off the power supply to the first load group vessel. Includes a zero volt circuit for detecting the zero volt vicinity of the alternating current power supply, a microcomputer that operates program using the signal from the zero volt circuit, the microcomputer detects the power failure when the signal from the zero volts circuit has run out The cooking device according to claim 1 or 2. A DC power source obtained from an AC power source, a switching power source that supplies power to the first load group from the DC power source, a low-voltage power source that supplies power to the microcomputer and the second load group from the output of the switching power source, A transistor for supplying the output of the low-voltage power source to the second load group, and a power failure detection circuit for detecting a power failure from the output voltage of the switching power source, and when the power failure detection circuit detects a power failure, the power from the output of the low voltage power supply to the second load group to a transistor for supplying a non-operating, before Symbol microcomputer detects that it no longer has the power supply to the second load group, the load of equipment while the non-driven state, the a microcomputer and nonvolatile external memory capable of transmitting and receiving data, the microcomputer outage The device status is written to the external memory when it is informed, and even when the microcomputer is reset, the status before reset can be read from the external memory before and after a power failure. Cooking device. Comprising a plurality of microcomputers, each of the microcomputers A heating cooker having a means for communicating with other of said microcomputer, and sends the state when the microcomputer detects the power failure to the other of said microcomputer , besides the microcomputer that has received the communication that the power failure condition, the heating cooker according to any one of claims 1 to 4, the load of equipment in the non-driven state. Comprising a plurality of microcomputers, each of the microcomputers A heating cooker having a means for communicating with other of the microcomputer, when a reset is applied to the microcomputer, since the communication signal is cut off The said other microcomputer is a heating cooker of any one of Claims 1-5 which detects that it is a power failure state, and makes the load of an apparatus non-driving state.