JPS633327B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reset circuit for a microcomputer.

Traditionally, we have used cooking equipment such as food processors,
Microcomputers are embedded in various devices,
Various controls are performed according to the program. The power supply voltage for this microcomputer is often generated from a commercial AC power supply. Therefore, looking at the reset circuit, there is one as shown in FIG. 1 as a basic one. In other words, an electrolytic capacitor C ₁ is connected between the power supply voltage V _DD and the voltage V _SS for the microcomputer μCPU, and when the power supply voltage V _DD is turned off, this power supply voltage V _DD slowly discharges through the circuit resistance, but
The reset capacitor _C2 is also discharged through the discharging diode D according to the power supply voltage _VDD . Therefore, when the power supply voltage V _DD is turned on again, the voltage at the INIT terminal of the microcomputer μCPU is not maintained at the H level (V _SS ), and the microcomputer μCPU operates. At this time, the preset and output of the program counter of the microcomputer µCPU do not become 0, so the program and output of the microcomputer µCPU do not operate normally and malfunction. This also poses a danger such as the motor suddenly starting to move.

In order to avoid such a situation, there is a circuit configuration as shown in FIG. First, the commercial AC power supply V is stepped down by a transformer T, and this is converted into a rectifier circuit.
Rectify it with REC, and create the power supply voltage V _DD for the microcomputer using smoothing capacitors C ₃ and C ₄ , resistor R ₁ , and Zener diode ZD. And the voltage
For the reset capacitor _C5 connected between V _SS and the INIT terminal of the microcomputer,
Resistors R ₂ , R ₃ , R ₄ , and transistors that discharge the capacitor C ₅ using the voltage V _D between the capacitor C ₃ and the resistor R ₁ as a signal source to generate a reset signal.
A discharge circuit is provided using Tr ₁ and Tr ₂ .
This causes the voltage V _D to discharge quickly, so the first
Compared to the one in the diagram, capacitor _C5 discharges faster and malfunctions are improved. However, in order to make the discharge circuits such as the transistors Tr ₁ and Tr ₂ work efficiently, it is necessary to increase the signal change and increase the voltage V _D , and the shape of the transformer also becomes large and heavy.

The present invention has been made in view of these points, and provides a reset circuit for a microcomputer that can prevent the microcomputer from malfunctioning even when the power is turned on again, and that can reduce the size and weight of the circuit without using a transformer. The purpose is to obtain.

The present invention creates a power supply voltage for a microcomputer from a commercial AC power supply using a diode, two resistors, a Zener diode, and two smoothing capacitors, and eliminates the need for a transformer, making the entire circuit smaller and lighter. The transistor is operated using a piezoelectric voltage as a signal source, and the reset capacitor is discharged, so that a quick reset is possible when the power is turned off, and there is no malfunction when the power is turned on again.

An embodiment of the present invention will be explained based on FIGS. 3 to 14. This embodiment shows an example of application to a cooking appliance, such as a food processor. First, a container 3 with an upward opening is attached to a mounting portion 2 formed in a main body case 1. A lid 4 for closing the container 3 is detachably attached. Also, a commutator motor 5 is placed next to the mounting portion 2.
A motor chamber 6 in which a motor is built in is vertically formed.
A cutout 7 is formed in the upper side of the motor chamber 6 facing the container 3, and a safety switch 8 is provided inside the cutout 7. A switch piece 9 for opening and closing the safety switch 8 is formed on a part of the circumferential side of the lid 4. Here, when the container 3 and the lid 4 are in a normal lock-set state, the switch piece 9 is located at the position shown by the solid line in FIG. If the lock position is deviated from the normal lock position, the safety switch 8 will be opened as shown by the dashed line in FIG.

Further, a gear 1 is attached to the motor shaft 10 of the motor 5.
1 is fixed, and intermediate gear 1 is connected to this gear 11.
a drive shaft 14 having a gear 13 meshing through 2;
is provided to protrude from the mounting portion 2.
A cutting blade 15 for cutting the food to be cooked is detachably attached to the drive shaft 14 in the container 3.
is provided. Various types of cutting blades 15 are selected and used depending on the type of cooking.

A display section 16 and an operation section 17 are provided on the bottom front surface of the main body case 1. first,
The display part 16 is a 7-segment LED 18 for 4 digits.
The first and second digits from the left indicate the time in seconds, and the third digit indicates whether safety switch 8 is on or off.
When turned off, the lid is displayed, and the fourth digit displays the operating speed level. Further, as shown in FIG. 5, the PC board 20 having the LED 18 is fixed to a decorative plate 19 provided to fit the front opening of the main body case 1. A transparent display plate 21 is fixed to the decorative plate 19 so that the lighting state of the LED 18 can be seen through the display section 16.
On the other hand, the operation unit 17 has a plurality of keys, from the left, a key 22 for setting the operating time in units of 10 seconds ("x10"), a key 23 for setting the operating time in units of 1 second ("x1"), Multiple predetermined operating speeds (in this example, stop speeds "0" and "1" to "6"
It consists of a key 24 for setting (stage), an auto pulse key 25 for intermittent operation every 2 seconds, a clear key 26, and a start/stop key 27 that also serves as a start/stop function. Looking at its specific structure, for example, the start/stop key 27, it is embedded in the decorative plate 19 as shown in FIG. An insulating spacer 31 is interposed therebetween to maintain the distance between the conductive parts so as to be able to come into contact with and separate from the conductive parts. other key 22
The same applies to etc. And said plaque 1
A flexible cover 32 made of polyester sheet or the like is provided entirely on the front surface of the device 9 . The cover 32 is bonded with an adhesive except for the display section 16, and the surface thereof has required printing corresponding to the display section 16 and the operation section 17, as shown in FIG. By providing such a cover 32, it is possible to completely prevent water from entering the precise key group for this type of cooking device that requires the use of water, and electrically connect the outside and the inside. It is completely insulated and can prevent short circuit accidents.

Next, the control circuit for the motor 5 will be explained with reference to FIG. First, the motor 5 is connected to a commercial AC power source 33 together with the safety switch 8, bimetal switch 34, and triax 35. In addition, these safety switch 8, motor 5, bimetal switch 34, triax 35
A diode 36, resistors 37 and 38, and a zener diode 39 are connected in parallel to. A smoothing capacitor 40 is connected in parallel to this Zener diode 39, and a resistor 38 is connected to the Zener diode 39.
A smoothing capacitor 41 is connected in parallel to both, and the Zener voltage of the Zener diode 39 produces the power supply voltage V _DD for the control circuit, that is, the microcomputer μCPU .

Here, the motor 5 has a brake coil 43.
One end of this brake coil 43 is connected to the OFF terminal A of the safety switch 8, and the other end is connected to an intermediate point between the armature 14 and the field coil 45. The other end of this field coil 45 is connected to another field coil 46.
It is connected to the triac 35 via. Further, the remaining brushes of the armature 44 are connected to the common terminal C of the safety switch 8.
The ON terminal B of the safety switch 8 is connected to the AC power supply 33.

On the other hand, a resistor 47 and diodes 48 and 49 are connected to a common terminal C of the safety switch 8, and a power supply frequency signal V _SIG is taken out. This power supply frequency signal V _SIG is input through a diode 50 to the _K8 terminal of the 4-bit one-chip μCPU 42. That is, the AC power supply 33 shown in FIG. 10a
From the voltage waveform of
Take out the negative side power supply voltage with respect to the voltage V _SS as shown in
The diode 49 extracts the positive power supply voltage from the power supply voltage V _DD as shown in Figure c, and the two are combined to produce a power supply frequency signal V _SIG as shown in Figure d.
This is the result. The diode 50 cancels the voltage drop of the diode 48 on the positive side of the voltage V _SS and inputs it to the K ₈ terminal of the μCPU 42 to adjust it so that it does not exceed the power supply voltage of the μCPU 42 .

Also, looking at the μCPU 42, first of all, the capacitor 51 between the V _SS terminal and the OSC ₂ terminal, and the capacitor 51 between the OSC 1 terminal and the OSC ₂ terminal
A built-in oscillator is caused to oscillate by a semi-fixed resistor 52 between the V _DD terminals, and a clock signal is given to the μCPU 42. And the INIT pin is the power supply voltage
The μCPU 42 is cleared when V _DD is at H level, and the program is executed when it is at L level. Therefore, the output is held at H level when the power is turned on, and the program counter is preset during that time to bring the output to L level.The output is connected between the INIT and V _SS terminals so that the output goes to L level later than the power supply voltage V _DD . An electrolytic capacitor 53 is provided as a reset capacitor that is charged and discharged. This electrolytic capacitor 53 reduces the power supply voltage V _DD
This prevents unexpected programs from running during startup. The collector of a PNP type transistor 54 is connected to the negative side of the electrolytic capacitor 53, the emitter is connected to the V _SS terminal, and the base of the PNP type transistor 55 is connected to the negative side of the electrolytic capacitor 53.
collector is connected. The collector of this transistor 55 is connected to the V _DD terminal via a resistor 56, and the base side has resistors 57 and 5 which divide the voltage (V _DD '-V _SS ) between the resistors 37 and 38.
8 are connected. As for the input relationship of the μCPU 42, the keys 22, 23, 24 are connected to the _K1 terminal.
The signal from the key 25 is input to the _K2 terminal.
Signals from the clear key 26 and start/stop key 27 are input, and _50Hz ,
A signal from a 60Hz changeover switch 59 is input. This selector switch 59 is for 50 Hz, and when it is closed and the voltage V _SS is input, a program for 50 Hz is executed. Also, regarding the output relationship of the μCPU 42, the signals from the O ₀ to O ₆ terminals are transmitted through the transistors 60, 61, 62, 63, 64, 65,
It is added to the emitter side of 66. As a result, transistors 60 to 66 are driven.
Appropriate current is applied to the 7 segments of LED 18,
By drawing current for each digit through transistors 67, 68, 69, and 70 by the output from the R ₀ to R ₃ terminals of the μCPU 42, the LED 18 is turned on for each digit. R ₀ terminal signal is key 2
Similarly, the signal from the R ₁ terminal is applied to the key 23, the start/stop key 27, and the R ₂
Signals from the terminals are given to the key 24 and the clear key 26, respectively. Furthermore, the _R5 terminal generates an output for the piezoelectric buzzer 71, and the transistor 7
If a key is pressed via 2, this piezoelectric buzzer 71 will sound for a short time when the timer ends. The signal from the _R7 terminal is input to the gate of the triac 35 via the transistor 73 as a gate signal.

Therefore, in this circuit, the power supply voltage V _DD is created without using a transformer and with resistors 37,
Since the voltage is stepped down by 38, it can be made smaller. In this case, by dividing the resistors 37 and 38 into two and connecting the capacitors 40 and 41, the power supply voltage
The ripple on V _DD can be reduced more than when the capacitor 40 is inserted only in this. Since the voltage at the voltage dividing point of resistors 37 and 38 (V _DD '-V _SS ) is used as a signal for the discharging circuit formed by transistors 54 and 55, etc., the power supply
When turned off, a reliable and quick reset is possible.
Malfunction of the μCPU 42 can be reliably prevented even if the power is turned on again instantly. As a result, even in the event of an instantaneous grounding accident such as during a power outage, the motor 5, which had been rotating at a low speed, will not suddenly rotate at a high speed. That is, according to this power supply circuit, the voltage V _DD ' normally maintains a voltage that is more negative than the power supply voltage V _DD with respect to the voltage V _SS . Therefore, by setting the voltage divided by the resistors 57 and 58 to a voltage slightly lower than the base-emitter saturation voltage of the transistor 55, the transistor 55 is normally turned on and the transistor 54 is turned on. is in the OFF state, so the electrolytic capacitor 53 is connected to the transistor 54.
and is electrically cut off. However,
Considering the case where the AC power supply 33 is turned off due to a power outage, etc., by appropriately setting the Zener voltage of the Zener diode 39, the constants of the capacitors 40 and 41, etc., the voltage V _DD can be reduced before the power supply voltage V _DD decreases. ′ begins to decrease the voltage first. Then,
The base voltage of transistor 55 approaches voltage V _SS , transistor 55 is turned off, and transistor 54 is turned on. As a result, in an instant,
The electric charge of the electrolytic capacitor 53 is discharged, and the μCPU 4
The INIT terminal of 2 will be pulled up to the voltage V _SS and a clear operation will be performed. Therefore, the power is instantly
If you repeat the ON/OFF cycle, for example, if you finish cooking, unplug the power outlet, and immediately restart cooking, the μCPU 42 will be cleared in an instant, so the μCPU 42 will not malfunction. The program will be executed without any problem.

Regarding the safety switch 8, if the lid 4 is locked in the normal position, the motor 5 can be energized, and even if the lid 4 is energized, if the lid 4 is removed or moved from the normal position, the safety switch 8 will be activated.
Switched to OFF terminal A side, brake coil 4
3 and armature 44 are field coil 4
5 and 46, which is a closed circuit connected in series, that is, a kind of short-circuited generator, and immediately stops the rotation of the cutting blade 15 under a large braking force. And, from a circuit perspective, safety switch 8 is connected to μCPU 4.
When the safety switch 8 is turned OFF, the power to the motor 5 is cut off, the gate signal to the gate of the triax 35 is stopped, and the timer time at that point stored in the μCPU 42 is The driving speed remains the same. In other words, the safety switch 8 is turned OFF while the lid 4 is removed.
The cooking time and speed can be set even in the current state, and the operation procedure is not limited, making it easy to use. If you are in the middle of cooking, even if you remove the lid 4 and add additional food, you can simply lock the lid 4 again and press the start/stop key 27 to continue cooking with the previous setting information. It is possible to restart the cooking process, the total cooking time can be known without calculation, and the cooking can be converted into data without relying on intuition. The result is always the best cooked food. Furthermore, the ON/OFF signal of the safety switch 8 is taken out from the common terminal C on the current-carrying side of the motor 5, and is also used as the power supply frequency signal V _SIG for the timer and the ON/OFF signal of the safety switch 8. The power supply frequency signal V _SIG , which is susceptible to adverse effects such as surge noise and high frequency noise based on the AC power supply 33, is turned off when the safety switch 8 is turned OFF, eliminating malfunctions and preventing injury to the cook or against his will. It is safe because the cutting blade 15 does not rotate and damage the food.

Next, the program of this embodiment will be explained according to the flowcharts of FIGS. 11 to 13.
First, when you turn on the power plug, the
RAM will be cleared automatically. The time setting is set to "C" which means continuous operation, and the operating speed is set to "0" from among the speeds of "1" to "6" and "0" which indicates no operation. . Next, check whether the _K4 terminal input is 50Hz or 60Hz, and if it is set to 50Hz, set the 50Hz flag. In this way, the initialization operation is performed.

Next, it is determined whether the lid 4 is locked, that is, whether the safety switch 8 is turned on, and if the safety switch 8 is turned on, the process moves to a 45ms counter. Then, it is determined whether the count content of this 45ms counter is 45ms or more, and if it is not 45ms or more, the power supply frequency signal V _SIG to the _K8 terminal is determined.
It is determined whether the voltage is at the H level or the L level with respect to the power supply voltage _VDD . Here, whether it is an H level or an L level, it is determined whether the H level or L level is the first one. i.e. _K8
H level to terminal → L level, L level → H
This detects the zero crossing of the power supply waveform as a level change. In this case, if the state with no level change continues, the first judgment result as to whether it is H level or L level is NO, and the half cycle of 50Hz is 10ms, 60Hz
The 45ms counter continues to count up for more than 8.3ms half cycle of 8.3ms, and when it reaches 45ms or more, the start flag is cleared and no lid is displayed while the time and speed are memorized. On the other hand, there is a level change, and it is difficult to determine whether it is H level or L level for the first time.
When it becomes YES, after clearing the 45ms counter,
It is determined whether the start flag is 1 or not, and if the start flag is not set, the program moves to the display program for the LED 18. That is, a dynamic display operation is performed in which output is output from terminals O ₀ to O ₆ and output is output from terminals R ₀ to _{R 3} depending on the digit. In this case, the input signal to the _K1 terminal or _K2 terminal corresponding to the output of the _R0 to _R2 terminals in this dynamic display operation is stored in the RAM, and if there is a signal, the key processing shown in Fig. 12 described later is performed. Move on to the routine. and,
In addition to operating this dynamic display, the display by the LED 18 is carried out by the current transformer power source 3
Four-digit lighting operations are performed within a half cycle of . By the way, when the safety switch 8 is OFF, it enters the 9.2 ms counter and displays 4 digits within 9.2 ms, which is the intermediate value between the 50 Hz half cycle of 10 ms and the 60 Hz half cycle of 8.3 ms. When the 4-digit display has finished, the input prohibition counter counts each time the routine runs, and if the interval between key inputs is 0.1 seconds or more, a flag is set to remove the input prohibition, and the key input is disabled. If the piezoelectric buzzer 71 is not ringing, it will pass through as is, but if it is still ringing, the piezoelectric buzzer 71 will clear the ringing in 15 ms. next,
It is determined whether the start switch is 1, and if it is not standing, it is determined whether it is the end buzzer, and if this end buzzer is not sounding, it is determined whether the initial safety switch 8 is ON. return.
These routines form a constant processing routine loop.

Next, the key processing routine will be explained with reference to FIG. In the above-mentioned constant processing routine,
After storing the input signal to the _K1 terminal or _K2 terminal corresponding to the output from the _R0 to _R2 terminals in the RAM during dynamic display operation, if there is a signal, the process moves to this key processing routine. When 4 is locked, the power supply frequency signal V _SIG that is always input to the _K8 terminal is omitted, the lid flag is set to 1, and the process returns to carrying the lit digit. Then, when there is an input to the _K1 or _K2 terminal, the key interval is checked to see if the input prohibition counter is released.
It is determined whether the input time is 0.1s or more, and if the input is prohibited, the input prohibition counter is cleared. On the other hand, if the input prohibition counter has been released, it is determined whether the key press operation is 30 ms or more. This determination is
In addition to the function of an input prohibition counter, this function is useful for preventing chattering of key inputs, uncertain key inputs, or noise entering the AC power supply 33. Thereafter, if the key is operated for 30ms or more, a signal is output from the _R5 terminal and the piezoelectric buzzer 71 is driven by the transistor 72.
Next, it is determined whether the input is to the _K2 terminal or the _K1 terminal. Here, if the input is to the _K2 terminal, it is determined whether it is the key 25 for auto pulse. In the case of this key 25, after the pulse signal is stored in the RAM, the process returns to the carry-up of the lit digit in the regular processing routine. Also, if the signal is not from the key 25, the start/stop key 27
If it is the start/stop key 27, it is further determined whether it is a start signal or a stop signal.
If it is for a stop, clear the start flag, memorize the time, speed, auto pulse signal, etc. as they are, and return to carrying the lit digit. If it is a start signal, continuous operation "C"
Or, after confirming that the timer is set, set the start flag to 1. Note that the determination as to whether the key is for start or stop is made by alternately distributing the signals of the start/stop key 27. In addition, start/stop key 2
If it is not 7, it is determined whether it is the clear key 26, and if it is the clear key 26, the program is returned to the start, the RAM is cleared, and the continuous operation is set to "C" and the speed is set to "0".

On the other hand, when there is an input to the _K1 terminal, it is determined whether it is the "x10" key 22 for time setting, and if it is the key 22, the 1 on the display section 16 is displayed.
Carry up the digit. In other words, if the second digit is x, by operating the key 22, "0x"
"1x", "2x"..."9x", and after "9x" there is only "C" which indicates continuous operation, and the second digit ("×
1'' digit) is memorized in the RAM, and when the next key 22 is input, this second digit is recalled and becomes ``0x''.
Further, if the key 23 is "x1" for time setting, the second digit ("x1" digit) on the display section 16 is incremented one by one. Furthermore, if it is the speed setting key 24, you can select "0", "1" to "6" by operating the key 24.
It is incremented in order of "0"... and the speed is set. In this case, the firing angle constant corresponding to the set speed step is stored in the RAM. In this way,
A loop of key handling routines is formed.

Further, the ignition processing routine will be explained with reference to FIG. 11 together with the timer processing routine shown in FIG. 13. First, by determining the start flag in the constant processing routine in which the start flag is set, a determination is made as to whether pulse setting is being performed. Then, if the pulse setting is not set, it is determined whether the speed is "6", and if the speed is "6", then
A 0.36 ms trigger pulse is given to the triac 35, and the timer processing routine shown in FIG. 13 is called. This timer processing routine uses the commercial power frequency of 50Hz or 60Hz, and if it is 50Hz, 50 pulses are counted as one second, and 60Hz or 60Hz is used.
If it is Hz, 60 pulses are counted as one second. First, the level of the power supply frequency signal V _SIG is selected, and timer processing is not performed at L level, but timer processing is performed only at H level. In the case of H level, determine whether the 50Hz flag is set,
If it's standing, it's 50Hz, so it goes into the 50 counter, and if it's not, it's 60Hz, so it goes into the 60 counter, and it's counted. When this count increases, it is counted by a 4-second repeat counter used for auto pulse or end buzzer.
The process up to this point is carried out in the same way even if the continuous operation is set to "C", but if the timer is set, it is determined whether the end buzzer is being sounded. If the end buzzer is being sounded, return to the original routine; if not, subtract 1 second from the current time. After subtraction, it is determined whether the set time has elapsed and reached 00 seconds. If there is still time left, return to the original routine, and if it is 00 seconds, set the end buzzer, clear the start flag, and return to the original routine.

Also, if the speed is set to something other than "6",
After determining whether the start flag is set and whether the speed is “6” or pulse setting, the firing angle corresponding to the set speed “1” or “5” is set in the RAM.
Call more. Here, at 50Hz or 60Hz, the firing angle is different even if the firing time is the same from the point of zero cross, so it is necessary to determine whether the 50Hz flag is set and to obtain the same power consumption depending on 50Hz and 60Hz, respectively. The 50 Hz firing angle counter and 60 Hz firing angle counter selected are used to count, and a firing angle pulse corresponding to the set speed is applied to the gate of the triac 35. Then, the timer is called and the process moves to the timer processing routine. Here, if the timer has ended and the end buzzer is sounding, it is determined whether the end buzzer is sounding, and further it is determined whether the end buzzer is within 2 seconds, and the timer processing routine is executed. Check the contents of the 4-second repetition counter at . If the time has exceeded 2 seconds, the end buzzer is stopped and the process returns to the initial determination of whether the safety switch 8 is ON in the regular processing routine. 2
If it is within seconds, the process moves to a timer processing routine to increment the repeat counter by 4 seconds.

In the case of pulse setting, the display on the display unit 16 will be "x, x, ^- , P", but the operation will be repeated at speed "6" for 2 seconds and rest for 2 seconds.
Therefore, if the pulse setting is set, it is determined whether the pulse counter, that is, the 4-second repetition counter, indicates the operating time or the rest time. If it is a running time, an ignition pulse is given as in the case of speed "6", and if it is a rest time, a timer processing routine is called to advance the timer.

Cooking according to the settings is performed by these constant processing routine, key processing routine, ignition processing routine, and timer processing routine.

Next, specific operations and their displays will be explained. First, when you plug in the power plug as a preparation step, it will be automatically cleared and the 14th
As shown in figure a, continuous operation "C" and speed "0"
is displayed. At this stage, the safety switch 8
The lid display can be turned on or off by turning it on or off. Next, the time is set by operating the keys 22 and 23. This setting range is 00 to 99 seconds, and if no operation is performed, continuous operation will occur.
For example, if you want to set 39 seconds after displaying "00" seconds, press the "x10" key 22 three times and
If the "1" key 23 is pressed nine times, a display as shown in FIG. 14b will appear. If you want to change the time set in this way, press the keys 22 and 23.
This can be done by continuing the operation, or by clearing with the clear key 26 and resetting. and,
The speed is set by operating the key 24. That is, the speed is set in stages "0" to "6" depending on the number of times the button is pressed. For example, if the key 24 is pressed five times, a speed of "5" will be set and displayed as shown in FIG. 14c. This speed change is also performed in the same way as the time change.

After setting the time and speed as described above, operation is started by operating the start/stop key 27. In this case, check whether the third digit lid on the display section 16 is lit. That is, if the lid 4 is locked in the normal position, the safety switch 8 is turned on and the display section 16 displays the lid as shown in FIG. 14d. On the other hand, if the lid 4 is not in the normal lock position due to being removed, the lid will not be displayed and the start/stop key 27 will not operate. In this way, lid display is performed,
In addition, since the time and speed are displayed on the same display section 16, for example, if the power outlet is disconnected, the entire display section 16 will be off and no display will be displayed, but on the other hand, if the lid 4 is removed, the display section 16 will not be displayed. It is possible to distinguish between the two even if only the flash display goes off and is not displayed and they do not operate in the same way. After all, it is possible to know all the setting states and the state of the cooking device just by looking at the display contents of the display section 16, and the cooking procedure can be improved and the cooking time can be shortened. After confirming the lid display in this manner, when the start/stop key 27 is pressed, the motor 5 is started and cooking begins. At this time, the time displayed on the display unit 16 is displayed by subtracting one second at a time as time passes. And when the remaining time reaches 00 seconds,
The piezoelectric buzzer 71 stops sounding. By the way, if you set the time like this or if the continuous operation "C"
, and if you want to stop the motor 5 during operation, you can press the start/stop key 27 again. By this operation, the start/stop key 27 acts as a stop key, the motor 5 is stopped, and the remaining time (or "C") and speed at that point are fixedly displayed on the display section 16. If you wish to resume operation, you only need to press the start/stop key 27 once more. After all, even if the continuous operation is set to "C" or the time is set, if you want to stop the operation depending on the cooking status etc. during operation, you can operate the start/stop key 27 that started the operation. , you can stop the cooking process without any confusion, and you can get food in the optimal cooking state.

Further, if intermittent operation is desired, pulse setting may be performed using the key 25 instead of setting the speed using the key 24. That is, when the key 25 is pressed, the display section 16 displays "P" instead of the speed, as shown in FIG. 14e. At this time,
Even if the time is continuous operation "C", it is "00".
~ "99" time setting (this time is the total time of operation and rest) may be used. Therefore, when the start/stop key 27 is pressed, intermittent operation is performed, but the speed is in "6" stages, and the operation is repeated for 2 seconds and then paused for 2 seconds. Incidentally, by setting a predetermined speed using the key 25 and repeating starting and stopping by operating the start/stop key 27, intermittent operation can be performed even at speeds other than speed "6". In this respect as well, the specifications can be expanded by providing a start/stop key 27 which also serves as a start/stop function.

Furthermore, if you want to run only the timer regardless of the motor 5, set the required time (for example, 60 seconds) as shown in Fig. 14f, set the speed to "0", and press the start/stop button. Just press 27. As a result, as time passes, the display is subtracted by 1 second, and when it reaches 00 seconds, the piezoelectric buzzer 71
The sound will sound to notify you that time is up. Such a function can be used as a reference for preparation time, etc.

As described above, the present invention creates a power supply voltage for a microcomputer by stepping down the AC power supply voltage using a resistor, so a transformer is not required and the circuit can be made smaller and lighter. Since the power supply voltage ripple is reduced, the voltage divided between the resistors is used as the signal source to operate the transistor and discharge the reset capacitor, so when the power is turned off, the micro The computer can be reset quickly, and even if the power is turned on again instantly, malfunctions of the microcomputer can be reliably prevented.

[Brief explanation of the drawing]

1 and 2 are circuit diagrams showing a conventional example, FIG. 3 is a perspective view showing an embodiment of the present invention, FIG. 4 is a vertical front view thereof, FIG. 5 is a plan view of the safety switch, and FIG. Figure 6 is a front view of the decorative plate, Figure 7 is a vertical side view of the display section, Figure 8 is a vertical side view of the operation unit, and Figure 9 is a vertical side view of the operation unit.
The figure is a circuit diagram, Figures 10 a to d are voltage waveform diagrams,
1 to 13 are flowcharts, and FIGS. 14 a to 14 f are front views showing display examples. 33...Commercial AC power supply, 36...Diode,
37-38...Resistor, 39...Zena diode, 40-41...Capacitor, 42...Microcomputer, 53...Capacitor, 54-5
5...Transistor.

Claims (1)

[Claims] 1 Connect a diode, two resistors, and a Zener diode in series to a commercial AC power supply, connect a smoothing capacitor in parallel to the Zener diode,
A different smoothing capacitor is connected in parallel to the Zener diode and one of the resistors connected to the Zener diode, a power supply voltage for the microcomputer is created by the Zener voltage of the Zener diode, and the microcomputer is reset. A reset capacitor is connected to the microcomputer, and two transistors are provided which operate using the divided voltage of the two resistors as a signal source to discharge the charge in the reset capacitor and generate a reset signal. A reset circuit for microcomputers featuring: