JPS5830091A - Cooking device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooking device such as a microwave oven that uses electricity as heating energy, and more specifically, it proposes a cooking device whose component parts are not subjected to the shock of rush current. be.

The magnetron drive circuit of a microwave oven includes a magnetic circuit, and the influence of inrush current is large, leading to deterioration and destruction of the magnetron. For this reason, the drive circuit is controlled so that the drive circuit starts driving the magnetron at a specific phase of the AC power supply so that no inrush current occurs. However, this is limited to the case where the power supply is turned on and off from the control means side, and if there is a momentary power outage on the power supply side, the phase at the time of recovery is undefined. A large inrush current may flow and damage various parts such as the magnetron.

The present invention has been made in view of the circumstances, and it is an object of the present invention to provide a cooking appliance that can cope with situations such as instantaneous power outages and effectively prevent the generation of rush current.

The present invention will be described in detail below based on drawings showing embodiments thereof.

FIG. 1 is a block diagram schematically showing the configuration of the main parts of the cooking device according to the present invention. In the figure, reference numeral 1 is a control unit provided as a control center of the cooker, which uses a microcomputer, etc., and is designed to emit signals for controlling the magnetron drive to a heating circuit 2, which consists of a magnetron and its drive circuit. There is. Reference numeral 3 denotes an input section for instructing heating, cooking patterns, etc., which consists of a □keyboard. Signals corresponding to key operations are input to the control section 1, and control based on this input data, that is, the output of the magnetron. control or timer control of driving time.

4 is a temperature probe installed to measure the temperature of the food to be cooked and to enable heating control based on the temperature measurement result, and has a structure such as housing a thermistor in a cylinder, and is inserted into the food. used.

This 14-degree probe is detachable from the cavity wall. Temperature probe output if A/b (analog/digital) converter 5 converts analog data into digital data, which is then taken into control s1.

Reference numeral 6 indicates a group of various switches, including a door switch 6az that closes the circuit when the door is closed; a probe switch 6b for monitoring the attachment and detachment of the temperature probe to the cavity wall (for example, a switch for fitting a plug connected to the temperature probe); (integrated with a receptacle provided on the cavity wall). The open/close states of these switch groups 6 are periodically read into the control unit 1.

7 is a power supply phase monitoring circuit (not shown) installed to monitor the phase of a commercial power supply, which includes a waveform shaping circuit, etc.;
The configuration is such that one pulse signal is periodically emitted as a monitoring signal at a specific phase of the commercial frequency power supply. Others 8#'
This is a blow-up battery that supplies power to enable operation of the control unit 1 and the like even in the event of an instantaneous power outage.

The control unit 1 controls the heating circuit 2 according to a cooking program prepared in advance based on the data given from the input unit 3, but in order to monitor the instantaneous interruption as described above, the control unit 1 controls the heating circuit 2 in accordance with a cooking program prepared in advance using data given from the input unit 3.
A program as shown in the 70-chart in FIG. 3 is also provided. The control unit 1 shown in the control section 1! f possible medium 7 lag 11.
The abnormal mode 7 lag 12 and kakunta 13 indicate the parts necessary for executing the above program, and the setting of the flag 11 indicates that the magnetron is permitted to be driven, and the setting of the flag 12 indicates that the magnetron is momentarily interrupted. An example is provided to illustrate this. In addition, the kakunta 13 is set to a predetermined value each time the monitoring signal is input from the power supply phase monitoring circuit 7, for example, if the power supply is 60 Hz, it is set to 20°; if the power supply is 50 Hz, it is set to 25, and the value of 1 mm, which will be described later, is set to a new value. A clock pulse with a period of seconds is applied to the count terminal as a counting target.

Next, based on FIGS. 2 and 3, the control related to momentary power interruption monitoring by the control unit 1 will be explained. When the monitoring signal is input, it is used as an interrupt signal and the interrupt subroutine program shown in FIG. 2 is executed. First, the 7 lag during drive permission is checked, and if this is set and drive of the magnetron is permitted, a signal is issued to the heating circuit 2 to drive the magnetron. Then, the above-mentioned value, 2o over 25, is set as the initial value in the kakunta 13, and the abnormal mode flag 1 is set as the initial value.
Reset 2. On the other hand, if the 7lag 11 is not set during drive permission, only the initial value is set to the kakunta 13 and the 7lag 12 is reset without driving the magnetron. Interrupts like this occur at 1 of the power supply frequency.
once per cycle, so 16.7 for 60Hz
In the case of milliseconds and 50 Hz, it is performed once every 20 milliseconds. Note that the signal issued to the heating circuit 2 for driving the magnetron is latched to become a continuous signal. In this way, the magnetron is driven in synchronization with the monitoring signal, and by setting the generation timing of the monitoring signal to an appropriate phase, generation of inrush current can be prevented.

Now, the program shown in FIG. 3 is repeatedly executed at a shorter time interval than the above program, in this embodiment, at a period of 1 millisecond. That is, first of all, the abnormal mode flag 12
is checked, and if it is not set, that is, if it is normal, a clock pulse is given to the kakunta 13 to perform l kakunto dankun.

Then, check whether there is a hollow output at 1%13.

As mentioned above, Kakunta 13 has 1 hourly commercial power supply.
A value slightly longer than the period (16, 7 or 20 ms) (
20 or 25) is set, and l is set every 1 millisecond.
As long as the power supply is normal, a hollow signal will not be generated and the contents of kakuntas 1 and 3 will return to their initial values before they reach zero.

・'If there is a momentary interruption, the execution of the program shown in FIG. 2 will be interrupted, resulting in the content of the kakunta 13 being zero, and furthermore, a hollow signal will be output. In such a case, the abnormal mode flag 12 is set and driving of the magnetron is prohibited.

When the abnormal mode 7 lag 12 is set in this way, the process branches to the abnormal mode. Note that power is supplied to the control unit 1 and the like during a momentary power outage by a backup battery.

In this abnormal mode 7''yg 12, the heating circuit 2 is kept off, but when the momentary interruption is recovered and the monitoring signal is input again, the program shown in Fig. 2 is executed if the flag 11 is set. The signal is then sent to the heating circuit 2 to drive the magnetron. Since this drive is resumed in synchronization with the monitoring signal, there is no risk of inrush current.Then, the abnormal mode flag 12 is reset and the magnetron is turned on. will be set to its initial value and return to normal operation.

As described below, the cooking appliance according to the present invention includes a power supply phase monitoring means for obtaining a monitoring signal related to the power supply phase, and starts timing every time the monitoring signal is input, and starts heating if the timing result exceeds a predetermined time. The device is equipped with heating control means that prohibits the operation of the cooking device, and the phase is controlled to reliably detect instantaneous power interruption and prevent inrush current even when the power is restored, thereby increasing the reliability of the cooking device. The present invention has excellent effects such as increasing safety and making long-term use possible.

[Brief explanation of the drawing]

FIG. 1 is a block diagram schematically showing the configuration of essential parts of a cooking appliance according to the present invention, and FIGS. 2 and 3 are flowcharts of a part of its control program. l...control section 2...heating circuit 3...input section
7... Power supply phase monitoring circuit patent applicant Sanyo'Sushiki Co., Ltd. agent Patent attorney Noboru Kawano Inuso 2 Figure 3 Figure

Claims (1)

[Claims] 1. A power supply phase monitoring means that obtains a monitoring signal related to the power supply phase, and a heating control means that starts timing each time the monitoring signal is input and prohibits driving of the heating means if the timing result exceeds a predetermined time. A cooking device characterized by comprising: