JPS5998220A - Controller - Google Patents

Abstract

PURPOSE:To perform the normal control after the time, when the temperature is allowed to reach a prescribed value, with a simple constitution, by constituting the device so that the duty ratio of a switching element which controls the power supply to a load, automatically after a certain time. CONSTITUTION:When a timer 11 is operated, transistors TRs 7 and 12 are made conductive. A variable resistance 6 is short-circuited by the conduction of the TR7, and a temperature setting means 5 is set to a maximum set temperature independently of the value of the resistance 6. By the conduction of the TR12, the output of an FF10 becomes low-potential, and a TR13 is turned off. At this time, since the temperature of the means 5 is higher than the temperature of a temperature detecting means 4, a control circuit 9 makes a triac 3 conductive by 100%, and a load 2 consumes 100% consumption power. When the temperature of the means 5 becomes equal to or lower than that of the means 4, the triac 3 is turned off. Next, when the operation time of a timer 11 elapses, TRs 7 and 12 are turned off. When the TR7 is turned off, the means 5 has the set temperature. When the TR12 is turned off, the circuit 9 supplies the consumption power corresponding to the operation of the FF10 to the load.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a control device that controls energization of a load connected to an AC power supply by using a switching element to switch the duty ratio of the switching element, such as a heating device, etc. The present invention relates to a control device suitable for use in a rapid heating circuit of a temperature control device.

PRIOR ART A conventional control device that uses a switching element to control energization of a load connected to an AC power source connects an on/off switch between the AC power source and the load, and connects the on/off switch in parallel to the on/off switch. By connecting a diode and turning on or off the on/off switch, a full wave or a half wave of the AC power source is applied to the load to control energization of the load.

The control device configured as described above has the drawback that the current supply to the load can only be switched between full wave and half wave, and the current supply to the load cannot be accurately controlled to a predetermined value.

OBJECTS OF THE INVENTION The present invention relates to a control device aimed at eliminating the above-mentioned drawbacks.

EMBODIMENT OF THE INVENTION Hereinafter, a case where an embodiment of the control device of the present invention is applied to a temperature control device for a heating device or the like will be described with reference to the drawings.

In Figure 1, 1 is an AC power supply, 2 is a load (heater),
3 is a switching element such as a triac (described below as a triac), and these elements are direct. They are connected in rows to form the main circuit. 4 is a temperature detection means of the heating device (omitted), 5 is a temperature setting means of the heating device, 6 is a variable resistor for setting the temperature (hereinafter referred to as a volume), 7 is an n, pn transistor connected in parallel with the volume 6 has been done. 8 is a zero cross detector that detects the zero cross of the AC power supply 1;
9 is a control circuit (hereinafter abbreviated as CON) that controls derivation or stop of a signal synchronized with the zero cross of AC power supply 1 in response to the signals from temperature detection means 4 and temperature setting means 5; 10 is an astable multi-by-break (hereinafter referred to as CON); (abbreviated as FF), high-level and low-level signals are derived at a constant cycle (duty ratio). 11 is a timer or latch circuit (hereinafter explained as a timer or timer), 12.13 is np
14 is a pulse transformer, and 15 is a diode.

In Figure 2, θmax is the maximum temperature, θ0 is the temperature set by volume 6, and T is the operating period of the timer (operating time).
It is.

In FIG. 3, (6) is when the timer 11 is operating, (B)
is when the timer is stopped, and in Fig. 3 (A) and (B), A is the waveform of the AC power supply 1, and the waveform 2 of the AC power supply 1 is the zero cross detector 8.
C is the signal waveform at the output end of FF10, 2 is the signal waveform at the output end of the timer 11, E is the signal waveform at the output end of C0N9, and H is the energization waveform of the load (heater) 2.

Next, the operating state of the temperature control device configured as described above will be explained.

When the timer 11 is activated at the initial stage of energization, a high level signal as shown in FIG. 3 is derived at the output terminal of the timer 11. Therefore, transistor 7.12 is conductive (on operation)
do. The ON operation of the transistor 7 electrically short-circuits the volume 6, which means that the temperature is set at the highest set temperature θmax regardless of the value of the volume 6.

(For convenience of explanation, the set (fixed) temperature during operation of the timer 11 will be explained as the maximum temperature, but other temperatures may be used.) Also, due to the ON operation of the transistor 12, the output of FF10 is electrically bypassed 3rd
As shown in Figure (6) C, the potential becomes low and the transistor 13
Since no signal is applied to the base of transistor 13
is off operation. At this time, since the temperature of the temperature setting means 5 (fixed at the maximum temperature θmax) is greater than the temperature of the temperature detection means 4, C0N9 generates a pulse signal as shown in FIG. is applied to the triac 3, the triac 3 is made 100% conductive, and the load (heater) 2 becomes 10 as shown in Fig. 3 (6).
Consumes 0% power consumption. Therefore, the temperature of the heating device etc. rises rapidly (as shown in Fig. 2, when the maximum temperature OmaX is reached, the temperature of the temperature setting means 5 (fixed at the maximum temperature θmax) ≦ the temperature of the temperature detection means 4, and C0N9 is the signal The triac 3 is turned off and the heater 2 is no longer energized.Then, when the temperature decreases and the temperature of the temperature setting means 5 becomes greater than the temperature of the temperature detecting means 4, the C0N9 derives a pulse signal and the triac 3 begins to derive the pulse signal. Load 2 is 10
0% energized. When the operating period T of timer 1 shown in FIG. 2 has elapsed, timer II no longer outputs an output signal as shown in FIG.
is off operation. The off-operation of the transistor 7 means that the regulator 6 is no longer electrically short-circuited, and therefore the set temperature becomes the set temperature θ0 by the regulator 6 as shown in FIG. Since the output signal of FFl0 is applied to the base of transistor 13 as shown in FIG.
3 repeats on/off operation in synchronization with FlPlo,
The output signal of C0N9 shown in FIG. 3B is applied to the pulse transformer 14 only when the transistor 13 is turned off. Therefore, the triac 3 conducts only during that period, and the load 2
corresponds to the conduction F as shown in Figure 3(B).
The load 2 consumes power corresponding to the operation of Fl0.

When the set temperature θ0≦the detected temperature, C0N9 stops outputting the signal, the triac 3 becomes conductive again at the duty ratio corresponding to the operation of FlPlo, and the load 2 consumes a corresponding amount of power.

As explained above, while the timer 11 is operating, the load 2 is
o % of power is consumed, and the temperature is unconditionally maintained at the maximum temperature, and the temperature is automatically lowered to the set temperature after a certain period of time, and the set temperature is maintained with a certain amount of power consumption.

Effects of the embodiments of the present invention Accordingly, when the timer is activated at the initial stage of power supply, the temperature of the load rapidly rises to the maximum temperature with 100% power, and this temperature is maintained for a certain period of time, so that the heating device is sufficiently preheated. It automatically lowers the temperature to the set temperature and maintains the set temperature with low power consumption, allowing for mild warmth.

Effects of the Invention Since the control device of the present invention has the above-described configuration, normal control after reaching a predetermined value can be reliably performed with an extremely simple configuration.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the control device of the present invention, Fig. 2 is a temperature characteristic diagram of Fig. 1, and Fig. 3 (6), (B).
1 is a waveform diagram of each main part in FIG. 1.

Claims (1)

[Claims] 1. In a control device that controls energization of a load connected to an AC power supply by using a switching element to switch the duty ratio of the switching element, means for automatically switching the duty ratio of the switching element after a certain period of time. A control device comprising: