JPS6331477Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a timer control circuit intended to solve the problem of temporary power outage countermeasures especially when the timer of a cooking appliance is set.

Conventionally, the memorization of timer settings in cooking appliances, etc. is done by an electromagnetic structure such as a latch relay, and even if there is a temporary power outage, for example, the timer remains set and the timer operation ends unless the latch is released. The device continues to operate even after power is turned on again. In such cases, the electromagnetic memory is replaced with a mechanical one, so the structure is complicated and may malfunction due to shocks such as dropping.
Therefore, if the timer time is simply replaced with an electronic circuit, the problems of malfunction due to the above structure and falling can be avoided, but in the case of a temporary power outage, etc., the timer operation must be manually re-driven even if the power is re-energized. There were some inconveniences such as not being able to do so.

The present invention has been made to improve the above-mentioned problems, and the object is to provide a timer control circuit that does not require artificial re-driving after power is turned on again even in the event of a temporary power outage. For this purpose, a combination of a capacitor and a diode constitutes a detection circuit that detects the charging voltage of the capacitor and obtains a desired output voltage.

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is a control device that controls control operations using a microcomputer, etc., and 3 is a timer set switch that sequentially lights up display elements 5, 6, 7, and 8 corresponding to timer time T. The timer time T is displayed. Display elements 5, 6, 7, formed on the common terminal
One end of 8 has a configuration in which a capacitor 19 is connected via a resistor 11 and a diode 14, and the capacitor 19 is charged when any of the display elements 5, 6, 7, and 8 is turned on. The resistors 9 and 10 are for dividing the common terminal voltage of the display elements 5, 6, 7, and 8, and from the voltage dividing point to the base of the transistor 12 whose load is the resistor 13,
By connecting the collector 2 to the base of the transistor 18 via the resistor 17 and the diode 16, and connecting both ends of the capacitor 19 to the output side of the resistor 15 and the transistor 18,
Each of the capacitors 19 has a configuration for discharging the capacitor 19. 2 is a DC voltage (V+) 23 and 24 are resistors, and these resistors 23 and 24 are for dividing the DC voltage (V+), and from the branch point of these resistors 23 and 24 via a resistor 21 and a diode 20, One end of the capacitor 19 and the emitter of the transistor 22 are connected to the base of the transistor 22 from between the diode 20 and the resistor 21, and the collector of the transistor 22 is connected via the resistor 26 to the base of a transistor 27 whose load is the resistor 25. It has a structure. The presence or absence of the charging voltage of the capacitor 19 detected by the diode 20, the resistor 21, and the transistor 22 is connected to the base of the transistor 27 whose load is the resistor 25 via the resistor 26. The output voltage of the collector is input to the control device 1. 4 is a timer start switch, which drives the operation of the timer and inputs an instruction signal;
Reference numeral 9 denotes a control element, which is composed of a thyristor or the like. 30 and 31 are AC power supply terminals.
31 has a circuit in which a heater 28 and a control element 29 are connected in series, and after setting the timer time T, the heater 28 is controlled via the control element 29 which is driven by the output signal of the control device 1. ing.
A detection circuit 32 is composed of transistors 22, 27 and resistors 25, 26, and is for detecting the voltage across the resistor 21 to obtain a desired output voltage.

The effect of the above configuration will be explained.

Taking a cooking appliance as an example, the timer set switch 3 is pressed as shown in FIG. 1, and one of the display elements 5, 6, 7, 8 corresponding to the timer time T is sent to be displayed. Also, when the timer set switch 3 is pressed, the capacitor 19 is charged via the resistor 11 and diode 14. At this time, the display element 5,
Current from one of transistors 6, 7, and 8 is input to transistor 12, but transistor 18 is OFF.
Since the operation is started, the capacitor 19 continues to be charged. Below, the explanation will be explained using Fig. 2. Fig. 2 A
By repeatedly pressing the timer set switch 3 indicated by , the timer time T corresponding to the display elements 5, 6, 7, and 8 in FIG. 2B, C, D, and E are lit in sequence. Now, set the display element 7 as shown in FIG. 2D, and then input the start switch 4 shown in FIG. 2F. Also, the capacitor 19 starts charging when the timer set switch 3 is set to D.
The charging voltage G is held only for the period H in FIG. 2. The timer operation is driven by the input F by the start switch 4, and the timer time T of D is started from the point. When the timer time T elapses and the point is reached,
A signal is output from the control device 1 to the control element 29,
The heater 28 starts heating and cooking begins.
When the cooking time reaches the point and the cooking ends, the timer time T
The display disappears when an OFF signal is sent from the control device 1 to the display element 7 for setting. That is, at the same time as D in Figure 2 turns OFF at point D, transistor 12 turns OFF and transistor 18 turns ON, so capacitor 19 is discharged and the voltage at point G in Figure 2 is turned OFF.
Turn off. The capacitor 19 continues to charge until the timer reaches the point, so even if there is a temporary power outage or the power is temporarily turned off, the charging voltage of the capacitor 19 remains the same as that of the diode 1.
4 and 20 are reverse biased, and the transistor 18 is in an OFF state, so there is no discharge and the charging voltage remains. That is, when the capacitor 19 reaches a predetermined charging voltage, the output voltage of the transistor 27 inputs information indicating that cooking is continuing to the control device 1 as shown in FIG. The input continues until the charging voltage disappears. Therefore, even during a temporary power outage, the information input function is maintained, so even after power is turned on again, cooking can be started while the timer setting continues. However, the display element 5,
6, 7, and 8 each indicate how many hours later they will operate, and although information on the remaining time is not available, when the power is turned on again after a temporary power outage, the H of the control device 1
When the charging voltage of the capacitor 19 is input to the terminal, it can be determined that there has been a temporary power outage during the operation of the timer T and that cooking has not been completed. If you create an emergency sequence for this state in the reset operation program, for example, if the maximum timer set time is 12 hours, you can start cooking after 1 hour or immediately after power is turned on again. The cooking process that follows the sea case that was initially set will be disrupted. For example, electric pots and jar pots are very effective means for cooking.

As described above, according to the present invention, by providing a capacitor that is charged by the current flowing through the diode in the display element, the capacitor continues to be charged while the timer is operating (when one of the display elements is lit). In addition, a diode and a resistor separate from those described above are provided to detect the charging voltage of the capacitor, and the presence or absence of the charging voltage is input to the control device via a separately provided detection circuit, thereby making it possible to operate the timer. Even if the power is temporarily interrupted due to a power outage, etc., it can be determined that the timer is still operating after the power is turned on again, so by using the reset operation program,
Cooking can be resumed automatically, and since it is an electronic circuit, there are no moving parts, so malfunctions due to drops etc. can be avoided.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a timer control circuit according to an embodiment of the present invention, and FIG. 2 is a diagram illustrating its operation. 1... Control device, 3... Timer set switch, 4... Timer start switch, 5, 6,
7, 8... Display element, 14, 20... Diode, 19... Capacitor, 21... Resistor, 32...
...Detection circuit.

Claims (1)

[Scope of utility model registration request] The timer set switch 3 and the timer start switch 4 are connected to the input side of the control device 1, and the capacitor is connected to the display elements 5, 6, 7, and 8 through the diode 14 connected to the output side of the control device 1. 19, and further this capacitor 1
Diode 20 and resistor 2 to detect charging voltage of 9
1, and a detection circuit 32 for detecting the voltage across the resistor 21 to obtain a desired output voltage.