JPH09113012A - Control device for air conditioner - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] In an air conditioner having a power relay for turning on / off a compressor or for supplying power to an outdoor unit, opening / closing of a contact of the power relay is synchronized with a peak of commercial power. The purpose is to prevent welding of the contacts. SOLUTION: The power ON / OFF request is recognized in ○ 1, the zero cross detection means of the power supply detects it, and it is detected from + to −.
The time ○ 1-b until the actual operation of the relay coil for power supply is turned ON is varied as a pseudo random number based on ○ 1-a. Power ON / OFF in this way
It is possible to average the relay contact timings by making the relay coil delay time random at each request.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner control device, and more particularly to control of a power supply relay.

[0002]

2. Description of the Related Art FIG. 4 is a conventional control block diagram of the present invention. FIG. 5 is an electric wiring diagram of a conventional air conditioner. FIG.
The operation sequence of the power relay is shown. In FIG.
1 is a power supply, 2 is a control circuit, and power relay ON / OFF
The request switches 3 and 4 are provided with a relay contact of the power source relay 4 and a relay driving call 4-b for driving the relay contact 4-a. 5 compressor motor, which is connected to the power supply 1 via the power supply relay 4.

The above-mentioned power source ON / OFF request switch 3
Is connected to the control circuit 2 and controls energization of the power supply relay coil 4-b in accordance with the input of the power supply ON / OFF request switch. Here, the power ON / OFF request switch is assumed to switch its state by turning the power on and off and controlling the temperature.

[0004]

According to the conventional control circuit of the present invention, due to variations in control timing and parts, the power supply relay is provided only on the half-wave side of the power supply voltage, that is, on the positive side, as shown in FIG. On or minus side, always ON / OF
When F is applied, a contact transition occurs and a welding phenomenon occurs.
Further, if the ON / OFF is performed at the peak of the power supply voltage even if the operation is not performed by only the half wave of the power supply voltage as described above,
The contact may be welded by the arc generated between the contacts. When the above phenomenon occurs, the relay cannot operate as it should, and it becomes impossible to control the compressor and control the energization of the outdoor unit.

[0005]

The control device for an air conditioner according to claim 1 of the present invention is to solve the problems of the above-mentioned contents, and is a power source zero-cross detecting means, a pseudo-random number generating means and its random number. The relay output delay time calculating means for delaying the relay output by means of, the power source zero cross detecting means, and the relay coil output means for varying the relay coil output timing according to the relay output delay time are provided.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION

First Embodiment of the Invention Hereinafter, a control device for an air conditioner according to an embodiment of the present invention will be described. FIG. 1 is a control block diagram, and FIGS. 2 and 3 show the operation sequence of the power relay, and the same parts as those of the conventional device are indicated by the same reference numerals.

In FIG. 1, an ON / OFF request detecting means 10 detects a power ON / OFF request input, and a power source zero cross detecting means 31, a pseudo random number generating means 22 and a relay output delay for delaying a relay output by the random number. It has a relay coil output means 30 for varying the relay coil output timing according to the relay output delay time of the time calculation means 20 and the power source zero cross detection means.

Next, the operation sequence will be described with reference to FIGS. Turning on the power ON / OFF request in Fig. 2
When the request ◯ 1 occurs, the zero crossing of the power source is detected, and the timing changes from + to −, and the time ◯ 1-b from the ◯ 1-a to the coil ON of the power supply relay coil operation is varied as a pseudo random number. In this way, by making the relay coil delay time random each time the power is turned on / off, it is possible to average the timing of the relay contacts.

An example of a pseudo random number generation method will be described below with reference to FIG.
A description will be given based on the timing chart shown in FIG. The timing after 1 msec from the power source zero cross is ◯ 1, and after 2 msec is ◯ 2. Power ON / OF
The previous position is stored in memory for each F request, and the position is changed for each ON / OFF request as follows. For example, 50H
In the case of Z, ○ 1 → ○ 11 → ○ 2 → ○ 12 → ○ 3 → ○ 1
3 → ○ 4 → ○ 14 → ○ 5 → ○ 15 → ○ 6 → ○ 16 → ○ 7
→ ○ 17 → ○ 8 → ○ 18 → ○ 9 → ○ 19 → ○ 10 → ○ 1
By doing so, it becomes possible to change the energization position of the power source in a pseudo-random number.

The air conditioner configured as described above is turned on / off by the control sequence of the power relay shown in FIG.
Therefore, even if the operating time of the power supply relay varies, the ON / OFF timing is randomized to prevent continuous operation at the peak of the power supply voltage.

[0011]

According to the controller of the air conditioner of the first aspect of the present invention, the power source zero-cross detecting means, the pseudo random number generating means, and the relay output delay time calculation for delaying the relay output by the random number of the pseudo random number generating means. Means, the power source zero-cross detection means, and the relay coil output means for varying the relay coil output timing according to the relay output delay time, the ON / OFF timing can be maintained even if the operating time of the power relay varies. By randomizing, the ON / OFF operation of the power supply relay has no positive or negative bias of the power supply voltage. Further, it has an effect of preventing continuous ON / OFF at the peak of the power supply voltage.

[Brief description of the drawings]

FIG. 1 is a control block diagram showing a control device for an air conditioner according to an embodiment of the present invention.

FIG. 2 is an operation sequence of a power relay showing a control device for an air conditioner according to an embodiment of the present invention.

FIG. 3 is a timing diagram showing an operation sequence of the power relay according to the embodiment of the present invention.

FIG. 4 is a conventional control block diagram.

FIG. 5 is an electrical wiring diagram of a conventional air conditioner.

FIG. 6 shows an operation sequence of a conventional power relay.

[Explanation of symbols]

1: Power supply, 2: Control circuit, 3: Power supply relay ON / OF
F request switch, 4: power supply relay, 4-a: relay contact, 4-b: relay drive call, 5: compressor motor, 10: ON / OFF request detection means, 31: power supply zero cross detection means, 22 : Pseudo random number generating means, 20: Relay output delay time calculating means for delaying, 30: Relay coil output means,

Claims (1)

[Claims] 1. An air conditioner having a power relay for turning on / off a compressor and for supplying power to an outdoor unit, in which a relay output is delayed by a power zero cross detection means, a pseudo random number generation means and its random number. With relay output delay time calculation means, power supply zero cross detection means and relay output delay time,
An air conditioner control device comprising: a relay coil output means for varying a relay coil output timing.