JPS59106011A - Controller for power supply rate to load - Google Patents

Abstract

PURPOSE:To match an electric apparatus to environmental conditions or the like to drive it in an optimum state by changing the rate of power supply to a load in two steps and making it possible to regulate one power supply rate at least. CONSTITUTION:A load 2 and a switching element 3 such as a TRIAC are connected in series to a commercial AC power source 1. When the operation time of a latch circuit 11 does not reach a prescribed time, a control circuit 9 supplies power interruptedly to the load 2 by 100% power supply rate to hold the load 2 at a maximum temperature. After the operation time of the latch circuit 11 reaches the prescribed time, the control circuit 9 supplies power interruptedly to the load 2 by the power supply rate determined by a duty ratio of a multivibrator 10 to hold the load 2 at a set temperature. The duty ratio of the multivibrator 10 is varied to drive the electric apparatus in an optimum state in accordance with environmental conditions or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a control device that switches the energization rate to a load.

<Prior Art> Control devices that switch the energization rate to a load have been conventionally used for various purposes.

For example, in heating devices such as electric blankets, current is passed at a 100% energization rate at the initial stage of energization of the heater, so that it can generate heat with maximum power and rapidly raise the temperature. After the time set by a timer etc. has elapsed, 1
By passing current at a energization rate considerably lower than 00% (for example, 50% energization rate), heat is generated with a small amount of electric power, and the temperature of the heating device is maintained at the set temperature.

Therefore, it is possible to rapidly increase the temperature at the initial stage of energization and maintain the set temperature after the set time has elapsed, and it is possible to obtain comfortable heating.

However, although the adjustment range of the set temperature in heating equipment is generally quite wide,
The energization rate when maintaining the set temperature is set to a predetermined value depending on the type of heating device, etc.

Further, the energization rate at the initial stage of energization is also set in advance to a predetermined value depending on the type of heating device and the like.

Therefore, at the initial stage of energization, the temperature is raised by the power determined by the preset energization rate, regardless of the ambient temperature, etc., and after a predetermined period of time, the temperature is increased regardless of the zero cavity temperature, the set temperature, etc. The set temperature is maintained using electric power determined by a preset energization rate.

Under such circumstances, the rate of temperature rise at the initial stage of energization changes, and especially when a rapid temperature rise is required,
If the temperature rises slowly, or if the set temperature is set quite low to maintain the set temperature after a predetermined period of time, the set temperature may be maintained using a large amount of power that is greater than the power required to maintain the set temperature. Therefore, it is not possible to accurately maintain the set temperature, resulting in drawbacks such as a temperature state considerably higher than the set temperature.

The above has only explained conventional examples when applied to heating equipment, but when applied to other equipment, the same drawbacks as above result from fixedly setting two types of energization rates in advance. This will result in

OBJECTIVES> An object of the present invention is to control the energization rate to a load to an optimum energization rate in accordance with atmospheric conditions, etc., thereby enabling electric equipment to be driven in an optimal state.

In order to achieve such an object, the present invention provides a control device that controls the energization rate of a load using a switching element. A switching means is provided for switching the energization rate to the load from one predetermined value to another predetermined value by controlling the energization rate, and an adjusting means is provided for adjusting at least one of the energization rates.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings showing examples.

<Embodiment> FIG. 1 is an electrical wiring diagram showing an embodiment in which the control device of the present invention is incorporated into a heating device such as an electric blanket.

(1) is a commercial AC power source, and a main circuit is constructed by connecting a load (2) consisting of a heater and a switching element (3) consisting of a triac or the like in series between both terminals of the AC power source.

(4) is a temperature detector that detects the temperature of the heating device;
5) is a temperature setting device that sets the temperature of the heating device;
) is a variable resistor for temperature setting, (7) is a switching transistor that shorts both ends of the variable resistor (6), and (8) is a pulse signal synchronized at the zero cross of the commercial AC power supply (1). (9) is a zero cross detector that outputs the output signal of the temperature detector (4), the output signal of the temperature setting device (5), and the zero cross detector (8).
It is a control circuit which takes as input the output pulse signal S and outputs a pulse signal synchronized with the output pulse signal S only when the detected temperature of the temperature detector (4) is lower than the set temperature of the temperature setter (5). 10) is a multivibrator whose duty ratio can be adjusted, (11) is a latch circuit consisting of a timer, self-holding means, etc., and (12) is a latch circuit (1
(13) is a switching transistor that is turned on by the output signal d of (1), and (13) is a multivibrator (10).
I), (14) is a pulse transformer that receives the output pulse signal e of the control circuit (9) and applies a gate signal to the gate terminal of the switching element (3). and (15
) is a diode.

The collector emitter terminal of the switching transistor (12) is connected in parallel with the base-emitter terminal of the switching transistor (13), and when the switching transistor (12) is in a conductive state, the output signal Cζ of the multivibrator (10) is Regardless, the switching transistor (13) can be maintained in a cut-off state.

In addition, the collector emitter terminal of the switching transistor (13) is connected in parallel with the negative side winding of the pulse transformer (14), and when the switching transistor (13) is in a conductive state, the output pulse signal of the control circuit (9) is Regardless of e, no gate signal is induced in the secondary winding of the pulse transformer (14).

The operation of the heating device with the above configuration is as follows.By turning on the power switch (not shown), commercial AC power is applied to the main circuit, and the latch circuit (11)
It is only necessary to set the operating time of the heating device to a predetermined time T, and the amount of heat generated by the heating device can be controlled in the following manner.

While the latch circuit (11) operates to maintain the output signal d at a high level, the switching transistor (7) (
12) are both conductive, the variable resistor is short-circuited, the temperature setter (5) outputs a signal equal to the selection of the highest set temperature, and the switching transistor (5) is turned on.
13) is kept in a cut-off state so that the output pulse signal e of the control circuit (9) can be applied to the pulse transformer (14).

Therefore, while the temperature detected by the temperature detector (4) is lower than the highest set temperature, the control circuit (9) outputs a pulse signal e that is synchronized with the output pulse signal of the zero cross detector (8). , is applied to the - secondary winding of the pulse transformer (14), so a gate signal can be induced in the secondary winding of the pulse transformer (14), thereby keeping the switching element (3) conductive, Load (2
) can be energized with a 100% energization rate (see Figure 3).

As described above, a rapid temperature rise is possible (see rapid temperature rise period in Figure 2), and when the maximum temperature reaches 9max, the detected temperature becomes higher than the highest set temperature and the control device (9) By stopping the pulse signal output of the controller (9) and causing the control device (9) to output the pulse signal again when the detected temperature decreases, the load (2) is intermittently energized at 100% energization rate, and the maximum temperature is (See maximum temperature maintenance period in Figure 2).

After the operating time of the latch circuit (1) reaches the predetermined time T, the output signal d becomes low level and both the switching transistors <7 and 12 are cut off, so the temperature setting device (5) , outputs a signal corresponding to the set temperature determined by the variable resistor (6), and makes the switching transistor (13) conductive.

However, if the output signal d remains open for a while after it becomes a low level, the temperature detected by the temperature detector (4) is the set temperature θ set by the variable resistor (6). , the control circuit (9) does not output any pulse signal e and continues to cut off the switching element (3) to prevent energization to the load (2) (see the temperature decreasing period in FIG. 2).

The temperature detected by the temperature detector (4) is a set temperature θ set by the variable resistor (6).

If it is not lower than , the control circuit (9) outputs a pulse signal e.

In addition, the switching transistor (13) is turned on while the output signal C of the multivibrator (10) is at a high level, and is cut off while the output signal C is at a low level, so that the output signal C of the multivibrator (10) is at a low level. Only during this period, the pulse signal e of the control circuit (9) is transferred to the pulse transformer (1
4) to make the switching element (3) conductive and energize the load (2) (see Figure 4).
.

Therefore, the temperature detected by the temperature detector (4) is the set temperature e0
If it is higher than that, the control circuit (9) does not output the pulse signal e at all, does not energize the load (2) at all, and
The temperature detected by the temperature detector (4) is the set temperature θ. If it is lower, the control circuit (9) continues to output the pulse signal e, but the multi-by-break (1o) repeatedly turns on and off the switching transistor (13).
The load (2) can be energized only during the cut-off period of the switching transistor (13), and the set temperature can be maintained with low power by energizing at a smaller energization rate than the maximum temperature maintenance period. (See the set temperature maintenance period in Figure 2).

Figure 15 is a diagram showing the signal waveforms of various parts when the energization rate to load (2) is further reduced to maintain the set temperature, and compared to the case of Figure 4, the power required to maintain the set temperature is Since it has a small value, it is suitable for maintaining the set temperature with a small amount of electric power. Incidentally, in the above explanation, there is no explanation about the means for changing the duty ratio of the multi-vibrator (10).For example, the duty ratio can be changed by means of changing the bias constant value of the multi-vibrator (10). It can be changed.

The bias constant value can be changed manually by the operator, or the bias constant value can be changed in conjunction with the operation of the variable resistor (6), and furthermore, the bias constant value can be changed by changing the zero ambient conditions, etc. It is also possible to change the bias constant value in accordance with the above, and in the latter case, the repeater does not need to perform any special operations, which greatly simplifies the operation.

In addition, although the embodiment described above has been described in which only the smaller energization rate of the two types of energization rates can be changed, it is also possible to change only the larger energization rate, or It is also possible to change both of the two types of energization rates.

Moreover, although only the embodiment in which the present invention is installed in a sampling tool has been described above, it goes without saying that the present invention can also be installed in other types of electrical equipment such as air conditioners.

<Effects> As described above, the present invention makes it possible to change the energization rate to the load in two stages, and at least one of the energization rates can be adjusted according to zero ambient conditions, etc., so that it can be applied to various electrical equipment. This has the unique effect of being able to drive the device in an optimal state according to the ambient air conditions, etc.

In particular, when it is installed in a heating device, it becomes possible to perform extremely detailed heating.

[Brief explanation of the drawing]

FIG. 1 is an electrical wiring diagram showing the control device of the present invention installed in a heating device. Figure 2 shows the change in load temperature over time, Figure 3 shows 1
Figures 4 and 5 are diagrams showing signal waveforms of each part when the load is energized with a energization rate of 00%, and Figures 4 and 5 are diagrams showing signal waveforms of each part when the load is energized with a energization rate of less than 100%. DESCRIPTION OF SYMBOLS 1... Commercial AC power supply, 2... Load 3... Switching element, 4... Temperature detector 5... Temperature setting device, 6... Variable resistor 7.12.13...
・Switching transistor, 8... Zero cross detector, 9... Control circuit, 10... Multivibrator 11... Latch circuit, 14... Pulse transformer Applicant Sharp Corporation

Claims (1)

[Claims] 1. A switching element is provided to control the energization rate to the load, and the load is energized at a preset energization rate of 1 before a predetermined time has elapsed, and at another preset energization rate after the predetermined time has elapsed. An energization rate control device for a load comprising a control circuit for controlling a switching element so as to energize the load, characterized in that the energization rate control device for a load is provided with an adjusting means for adjusting the energization rate of at least one side. .