JPH03215121A - power control device - Google Patents

Abstract

PURPOSE:To reduce rush current upon starting the conduction of current through a load such as a heater or the like by a method wherein the conduction of the electric current to more than two sets of load is not effected simultaneously regardless of the set value of a power setting means. CONSTITUTION:Power setting means 7 is set at full conduction at the time of starting power supply through heaters 1-3. During initial several periods, the trigger signals of two-way thyristors 4-6, which are outputted from a gate power distributor 9, are outputted one by one at every half period sequentially. Accordingly, the heaters 1-3 are energized one by one at every half period sequentially. In the case of halogen heater, for example, rush current in the initial half period is about 20 times of a rated current and, thereafter, the value of the rush current becomes same as the value of the rated current. Accordingly, the rush current upon starting of power supply through loads such as the heaters 1-3 or the like can be reduced. According to this method, affections on other instruments such as illuminating equipments or the like or the blow out of a fuse can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a power control device for electric cookers and the like used in general households.

2. Prior Art A conventional power control device of this type was disclosed in Japanese Patent Publication No. 63-1820.
As shown in Publication No. 7, each heater is operated at zero volts according to the set power in a combination that does not cause flicker in the lighting device.

FIG. 3 is a block diagram of the circuit. In this figure, heaters 1, 2.3 are connected in series with bidirectional sirinutors 4, 5.6, respectively.

7 is a power setting means for setting the heating power of the heater.

The commercial frequency counter 8 generates a pulse (hereinafter referred to as zero volt pulse) near the zero cross of the AC power supply,
Based on this zero volt pulse, the gate power distributor 9 connects the bidirectional thyristors 4, 4, and 4 in a predetermined combination so as to achieve the firepower set by the power setting means 7.
5. Output trigger signals to 6, respectively.

Upon receiving the trigger signal, the bidirectional thyristors 4, 6.6 become conductive, and current is supplied to the heaters 1, 2, 3 connected in series.

FIG. 4 shows the heater energization combinations. In other words, in order to avoid flickering in the lighting equipment, the number of heaters that are turned on at the same time is set to be the same as possible.
This prevents periodic fluctuations in the AC voltage.

The user can set the desired heating power using the power setting means 7, but when the power supply to the heaters 1, 2.3 starts (
When cooking begins), the power is set to full power to quickly heat the food.

Problems to be Solved by the Invention However, with the above configuration, although it is possible to prevent 7 licker in the lighting device, it is not possible to suppress the inrush current due to the low cold resistance of the heater at the time of starting energization. This inrush current caused fuses in the AC line to melt, and voltage drops caused by the inrush current caused other equipment to malfunction.

The present invention solves these problems and provides a power control device that reduces rush current at the time of starting energization to a load such as a heater.

Means for Solving the Problems In the first means, when starting energization to a load such as a heater, a trigger signal is simultaneously sent to two or more switching elements from a gate power divider, regardless of the setting value of the power setting means. It is configured so that it does not output.

In the second means, when starting energization to a load such as a heater, the output of the trigger signal of the switching element outputted from the gate power divider is delayed, and the K configuration is configured such that the output is delayed after the peak of the AC waveform and before the zero cross. did.

In the first method, when starting to energize a load such as a heater, only one of the multiple loads such as a heater is energized, and the inrush current is smaller in number than when all loads start energizing at the same time. It is suppressed to one-fold, and there is no possibility of the AC line fuse blowing out or the lighting becoming dim for a moment.

In the second method, the current supply to the load such as a heater is A
This is performed while the C waveform is falling, suppressing the rise in current value and reducing inrush current.

Example An embodiment of the present invention will be described below.

The block diagram is the same as that in FIG. 3, and its explanation will be omitted here.

FIG. 1 is an energization pattern diagram at the time of starting energization to the heater of the power control device of the first means.

At the start of energization to the heater, which is a type of load, the setting value of the power setting means 7 is set to full energization, as described in the related art, but during the first few cycles (here, 1.6
period = section 10), the gate power divider 9 sequentially outputs a trigger signal to the bidirectional thyristors 4, 5.6, which are a type of switching element, one at a time every half period, and are energized one by one every half cycle.

If heaters 1, 2.3 are Tatoeha halogen heaters, the maximum thermal power of a typical stove is about 1.61W, so the rated current per heater is AC200V.
In the case of a power supply, it is about 2.6▲.

The inrush current of a halogen heater is usually about 20 times the rated current during the first half cycle, and from then on, a current close to the rated current flows, so in this example, An inrush current of about 60▲ flows during .6 cycles, which is suppressed to one-third of the 150▲ that would occur if all heaters were energized at the same time.

With a general AC power supply, an inrush current of about 60▲ for several cycles will not cause the 7-use to melt, nor will the equipment to which the power is supplied malfunction.

FIG. 2 is an energization pattern diagram at the time of starting energization to the heater, which is one of the loads, of the power control device of the second means.

At the start of energization to the heater, the set value of the power setting means 7 is set to full energization as described in the prior art, but during the first few cycles (here, 2 periods and 2 sections 11), the gate power distribution is The trigger signal of the bidirectional thyristor, which is a type of switching element, output from the heater 1 is delayed from the peak of the AC voltage waveform until the zero cross.
, 2.3 is started when the AC waveform falls, suppressing the rise in current value and reducing inrush current.

Effects of the Invention As described above, according to the present invention, it is possible to provide a power control device with less inrush current to loads such as heaters, and prevent fuse blowing and influence on other equipment such as lighting equipment. can do.

[Brief explanation of drawings]

FIG. 1 is a power supply pattern diagram of a heater according to an embodiment of the present invention, FIG. 2 is a diagram of a heater conduction pattern diagram according to another embodiment of the present invention, and FIG. 3 is a block diagram showing the basic configuration of a power control device. FIG. 4 is an energization pattern diagram of a conventional heater. 1, 2.3... Heater (load), 4, 5.
6... Bidirectional thyristor (switching element), 7... Power setting means, 8... Commercial frequency counter 9... Gate power divider.

Claims (2)

[Claims] (1) A plurality of loads, a plurality of switching elements connected in series to each of these loads, a power setting means, a commercial frequency counter, and based on the outputs of the power setting means and the commercial frequency counter, the It consists of a gate power divider that determines the output to the switching element and outputs a trigger signal, and when the power starts flowing to the load,
A power control device characterized in that two or more of the loads are not energized at the same time regardless of the setting value of the power setting means. (2) a plurality of loads, a plurality of switching elements connected in series to each of these loads, a power setting means, a commercial frequency counter, and based on the outputs of the power setting means and the commercial frequency counter, the It consists of a gate power divider that determines the output to the switching element and outputs a trigger signal, and when the power starts flowing to the load,
A power control device characterized in that a trigger signal for the switching element outputted from the gate power divider is delayed, and current is supplied to the load after the peak of the AC waveform until the zero cross.