JPH0541095U - High frequency heating device - Google Patents

Abstract

(57) [Summary] [Purpose] Output data corresponding to each high-frequency output value of the magnetron sent to the inverter power supply and stored in the non-volatile memory controlled by the microcomputer, and the numeric keypad provided on the keyboard. The setting can be easily re-set by, and the complexity of output adjustment is reduced. [Configuration] A writable / readable non-volatile memory 2 is externally attached to the microcomputer 1, and when the microcomputer 1 is in an inspection mode, the output data stored in the non-volatile memory 2 is directly operated by the operation of the numeric keypad or the like. It was rewritten and stored again in the non-volatile memory 2.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an output setting method for a high-frequency heating device that drives a magnetron with an inverter circuit.

[0002]

[Prior Art]

 It is equipped with an inverter circuit that rectifies a commercial AC power source and converts it into AC power of a frequency (tens of kHz) according to the high frequency output set by the customer by turning the switching element on and off. This inverter circuit supplies power to the magnetron. In the high-frequency heating device to perform, as a means for sending the set output data to the control circuit of the inverter circuit, the microcomputer refers to the internal memory based on the set output and uses this data as the set output data as the control circuit. The method of communication is taken.

[0003]

[Problems to be solved by the device]

 However, according to this method, the set output data is stored in the mask ROM in the microcomputer and cannot be changed. Considering the characteristic variations of products, it is very difficult to obtain the same specified high frequency output for all products with this uniformly determined output data.

For this reason, conventionally, it is necessary to provide a hardware or soft adjusting means in consideration of variations in heating efficiency and circuit constants. Therefore, normally, a fine adjusting volume is provided in an inverter control circuit. It is installed inside the device and is used to adjust to the specified output while measuring.

However, since the adjusting volume is generally mounted on the substrate on which the inverter circuit is configured, the adjusting of the volume must be performed without mounting the product cabinet, and the adjustment is completed as a product. There was a difficulty that it could not be adjusted depending on the condition.

In order to eliminate such difficulties, the adjustment work can be performed by using various keys provided in the operation unit, and the input current to the inverter circuit equipped with the switching element for supplying electric power to the magnetron is measured. Means and a microcomputer, and an inverter control circuit that adjusts the power supplied to the magnetron so that the current detection signal by the input current measuring means has a required value, and a nonvolatile memory accessed by the microcomputer. , And a microcomputer configured to have a means for performing feedback control of the power supplied to the magnetron based on the data stored in the nonvolatile memory and the current detection signal. ..

In addition, the microcomputer calculates a “control constant” from the measured input to the inverter circuit at the time of magnetron oscillation and the current detection signal output by the input current measuring means at that time, and the “control constant”. It is configured to have a means for storing “” in a non-volatile memory and a means for feedback controlling the power supplied to the magnetron based on the “control constant” stored in the non-volatile memory.

Moreover, in the former case, data (signal level at that time) corresponding to the state of the current detection signal output from the input current measuring means when the rated input current actually flows to the inverter circuit is written in the nonvolatile memory in advance. For example, when the microcomputer receives a signal that oscillates the magnetron at the rated output, it accesses the nonvolatile memory and reads the previously written data (signal level). The signal level of the current detection signal is compared with the signal level of the current detection signal, and when the signal level of the current detection signal is lower than the signal level of the read data, the data stored in the non-volatile memory is changed to “the former / The latter is higher than the former by prolonging the on-time of the switching element by multiplying the ratio by the ratio of the latter. Sometimes, the above data is also multiplied by a coefficient corresponding to the ratio of "the former / the latter" to shorten the on-time of the switching element so that both the rated output value of the specified magnetron and the actual output value of the magnetron become equal. The on-time of the switching element is determined so that the input current to the inverter circuit becomes the rated current immediately.

Further, in the latter case, when the microcomputer receives a signal for oscillating the magnetron at the rated output, for example, the nonvolatile memory is accessed and the "control constant" stored therein is read out, and the input current measuring means is momentarily read. The value of the output current detection signal is multiplied by the "control constant" to calculate the actual input current value flowing into the inverter circuit, and the calculated input current value and the rated input current value are compared. When it is lower than the former, the ON time of the switching element is lengthened as in the former, and when the latter is higher than the former, the ON time of the switching element is shortened so that the two become equal. The input current to the circuit is set to the rated current immediately. (Refer to Japanese Patent Laid-Open No. 3-167779) The above-mentioned configuration is based on the assumption that the inverter circuit that feeds back the input always operates correctly, and is established when the "variation" of the inverter circuit is large. There are difficulties that cannot be done.

On the other hand, there is an example (see Japanese Patent Application Laid-Open No. 54-143649) in which the equipment used is maintained and inspected by using a plurality of operations of the keys provided on the operation panel. It is only a key operation to perform maintenance and inspection of the equipment used, so that the data once stored as in the present invention can be reset by key operation, and the data set at this time can be used as new data of the equipment in operation. It has not become.

[0011]

[Means for Solving the Problems]

 The present invention has been made to solve the above-mentioned problems, and it is a magnetron driven by a high-frequency power source created by an inverter circuit, a microcomputer for controlling the driving of the magnetron, and a writing device external to the microcomputer. It is equipped with a non-volatile memory that can be read / written and a keyboard that is equipped with a numeric keypad connected to a microcomputer, and stores data corresponding to each high-frequency output value of the magnetron in the non-volatile memory. When the micro computer is in the inspection mode different from the normal operation mode, it can be arbitrarily reset by operating the numeric keypad switch.

[0012]

[Action]

 By doing this, the high frequency output value of the magnetron to be adjusted after shifting to the inspection mode is set, and the data corresponding to each high frequency output value of the magnetron stored in the nonvolatile memory by the microcomputer. The data corresponding to the high frequency output value selected from the above is sent to the inverter circuit to start the operation of the magnetron.

During this operation, for example, a measuring device is connected to monitor the output, and the output is compared with data corresponding to the selected high frequency output value, and the monitored output is changed to the selected high frequency output value. When the data differs from the corresponding data, operate the corresponding key from the above numeric keypad switch to match the above data value stored in the non-volatile memory by the microcomputer with the above monitored output, and rewrite this data. It is stored in the non-volatile memory as new data corresponding to the set high frequency output value of the magnetron.

The changed new output data corresponding to each high-frequency output value of these magnetrons is stored in the non-volatile memory during the operation of the magnetron and then immediately transmitted to the inverter circuit, and the output adjustment of the magnetron is performed as described above. This can be easily done by pressing the corresponding key on the numeric keypad switch.

[0015]

【Example】

 An embodiment of the present invention will be described below.

FIG. 1 is a schematic circuit diagram of a high frequency heating apparatus showing an embodiment of the present invention, and FIG. 2 is a diagram showing the main signal flow thereof.

In FIG. 1, reference numeral 1 denotes a microcomputer, and a writable / readable nonvolatile memory 2 described later is externally attached to the microcomputer 1. Reference numeral 3 is an inverter circuit composed of a full-wave rectifier circuit R, a magnetron driving transformer T, a capacitor C, a diode D, a switching element S, etc., and a microcomputer 1 via an element control circuit 5 for controlling the switching element S on / off. It is connected to the.

In the element control circuit 5, the data in which the central value of the product variation corresponding to each high frequency output value of the magnetron M stored in the non-volatile memory 2 is written is supplied to the clock signal CLK as the data signal DATA. Inputs are made in synchronization via the microcomputer 1.

The non-volatile memory 2 uses the read enable signal RE from the microcomputer 1 to read data, the write enable signal WE to write data, and the address of the data is designated by the address signals AD0 to AD5, respectively. The data input and output signals D0 to D5 are performed.

Reference numeral 4 denotes a keyboard, which is provided with a ten-key switch which is operated when the high-frequency heating device is in operation and a start key which is used as follows when adjusting the output of the magnetron M.

To change the data, use the numeric keys “0” to “9” and the “Start” key on the keyboard 4, and after pressing the “Start” key while the magnetron M is operating, The data is directly input by using the numeric keys to rewrite the data in the non-volatile memory 2.

Reference numeral 6 denotes a magnetron drive circuit, which is driven by a current flowing through a magnetron drive transformer T via the switching element S, and by the drive, a high frequency power source created by the inverter circuit 3 is supplied to the magnetron M. Is working. Next, the operation of this embodiment will be described.

The microcomputer 1 can operate the heating function by the same operation as usual even after shifting to the inspection mode.

When adjusting the output of the magnetron M, for example, 500 W is selected and set from the high-frequency output values of the magnetron 1 to be adjusted, and the adjusting procedure is started.

Now, for example, 36 corresponding to the selected high frequency output value (500 W) is stored in an address of the nonvolatile memory 2.

After the adjustment procedure is started, the chip select signal CS from the microcomputer 1 becomes LOW as shown in FIG. 2, and the nonvolatile memory 2 becomes active.

At the same time, the read enable signal RE becomes LOW, so that the nonvolatile memory 2 is in a read state.

Therefore, the microcomputer 1 obtains the data 36 from the nonvolatile memory 2 by referring to the above address.

By starting transmission of this data 36 as the signal DATA to the element control circuit 5 in synchronization with the clock signal CLK, the switching element S 1 in the inverter circuit 3 starts driving.

The driving of the switching element S starts the operation of the inverter circuit 3, and a current flows through the magnetron driving transformer T.

The magnetron drive circuit 6 is driven by the current, the high frequency power generated by the inverter circuit 3 is supplied to the magnetron M by the drive, and the magnetron M starts operating.

The output of the inverter circuit 3 during operation is monitored by a measuring device at any time, and the output is compared with the data (36) corresponding to the selected high frequency output value.

According to the compared data, when the former is lower than the latter, the numeric keys “0” to “9” and the “start” key on the keyboard 4 are used, and “start” key → “3” → “8” , The microcomputer 1 sets the read enable signal RE to HIGH and the write enable signal WE to LOW to put the nonvolatile memory 2 into a write state. The data (38) changed in place of the above data (36) stored in the non-volatile memory 2 is used as the new data (38), and the data (36) in the non-volatile memory 2 is stored in the same data (36). Write in the address storage area.

When the writing is completed, the microcomputer 1 sets the write enable signal WE to HIGH and the read enable signal RE to LOW to return the nonvolatile memory 2 to the read state, read the new data (38), and read this new data (38). 38) to the inverter 3 circuit.

On the contrary, when the former is higher than the latter, the data (36) stored in the nonvolatile memory 2 is changed by an operation different from the above.

As described above, the output can be changed by a simple key operation, and an optimum data value can be selected by monitoring this with a measuring instrument at any time, so that the output can be easily adjusted.

[0037]

[Effect of the device]

 As described above, the microcomputer that controls the drive of the magnetron is equipped with a non-volatile memory that can be written / read externally attached to the microcomputer and a keyboard that has a numeric keypad connected to the microcomputer. When in the mode, the data corresponding to each high-frequency output value of the magnetron stored in the non-volatile memory can be reset arbitrarily by key operation, so that the output can be easily adjusted and the conventional cabinet can be adjusted. It was possible to simplify the work of adjusting the output, which could not be done without removing.

Further, since the adjustment can be performed relatively easily, the variation of the components used in the inverter circuit can be increased within the range permitted by the circuit operation, and the cost down of the components themselves can be expected.

[Brief description of drawings]

FIG. 1 is a schematic circuit diagram of a high-frequency heating device showing an embodiment of the present invention.

FIG. 2 is a diagram showing a main signal flow of the same.

[Explanation of symbols]

 1 Microcomputer 2 Non-volatile memory 3 Inverter circuit 4 Keyboard 5 Element control circuit 6 Magnetron drive circuit S Switching element M Magnetron

Claims (1)

[Scope of utility model registration request] 1. An inverter circuit (3) comprising a full-wave rectifier circuit R for rectifying and smoothing a commercial power source to produce a DC power source, a magnetron drive transformer T, a capacitor C, a diode D, a switching element S, and the like. , The inverter circuit
A magnetron M created in (3) and driven by a high-frequency power source supplied by the control of the switching element S; and an element control circuit (5) for on / off controlling the switching element S for driving the magnetron M. A microcomputer (1) for controlling driving of the element control circuit (5), and a writable / readable non-volatile memory (2) externally attached to the microcomputer (1),
In a high-frequency heating device connected to the microcomputer (1) and comprising a keyboard (4) provided with a numeric keypad and the like, data corresponding to each high-frequency output value of the magnetron M is stored in the non-volatile memory (2). The data can be stored and changed by operating the ten-key switch when the microcomputer (1) is in an inspection mode different from the normal operation mode. The non-volatile memory is operated by operating the ten-key switch.
A high-frequency heating device characterized in that the data stored in (2) is arbitrarily reset.