JP2694789B2 - Refrigerator control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for controlling a rotation speed of a fan for circulating cold air in a refrigerator.

[0002]

2. Description of the Related Art Refrigerators are constructed such that cold air generated by a refrigeration cycle is circulated by a fan to cool the inside of the refrigerator. The rotation speed of this fan is controlled by phase control. For this reason, it is necessary to detect the power supply frequency, and the power supply frequency is detected by taking in the power supply waveform and shaping the waveform into pulses at the same time when the power is turned on.

[0003]

In the conventional refrigerator control device as described above, the detection of the power supply frequency is started when the power is turned on. The pulse waveform may be missing and the power supply frequency may not be detected normally. Therefore, there is a problem that the rotation speed of the fan does not become normal during the phase control.

The present invention has been made to solve the above problems, and provides a control device for a refrigerator which can always detect the power supply frequency normally and can stably obtain the rotation speed of the fan during phase control. The purpose is to do.

[0005]

A control device for a refrigerator according to a first aspect of the present invention controls a rotation speed of a fan for circulating cold air by phase control and determines a power supply frequency detection start timing as a power supply frequency determining means. Therefore, the power is turned on for a fixed time.

Further, the control device for the refrigerator according to the second aspect of the invention controls the rotation speed of the fan for circulating the cool air by phase control, shapes the power supply waveform into pulses, and detects the power supply frequency from the interval of the pulses. The power supply frequency determining means delays the detection start time from the power-on for a certain period of time, measures the intervals of each pulse multiple times, and determines the power supply frequency when all of these intervals are the same. It is a thing.

[0007]

In the first aspect of the present invention, the power supply frequency detection start timing is delayed for a fixed time after the power is turned on. Therefore, the power supply frequency is determined after the power supply waveform is stabilized.

Further, in the second aspect of the invention, the interval of each pulse is measured a plurality of times, and the power supply frequency is determined when the results are all the same. Therefore, if there is an abnormality in the waveform during the measurement, the power supply is The frequency is not determined.

[0009]

【Example】

Embodiment 1 FIG. 1 to 4 are views showing an embodiment of the first invention of the present invention, FIG. 1 is an overall configuration diagram, FIG. 2 is a circuit diagram of a control device, FIG. 3 is a waveform diagram for explaining operation, and FIG. It is an operation | movement flowchart, and the same code | symbol shows the same part.

In FIG. 1, (1) is a compressor for circulating a refrigerant, (2) is an evaporator for evaporating this refrigerant, and (3) is an evaporator.
A fan that circulates the cool air cooled by (2) in the refrigerator,
(4) is a thermistor for detecting the temperature of the freezer compartment (5), (6) is an AC power supply, (7) is a control device consisting of a control board, and (8) is a power supply.
A power supply frequency determining means for determining the power supply frequency by inputting the waveform of (6), and (9) is a fan based on the output of the thermistor (4).
Fan rotation speed determining means for determining the rotation speed of (3), (1
Reference numeral 0) is a control means for controlling the operation, stop, and rotation speed of the compressor (1) and the fan (3).

In FIG. 2, (11) is a thermistor (4) and a voltage dividing resistor for dividing the voltage, (12) is a microcomputer (hereinafter referred to as a microcomputer) constituting each of the above means (8) to (10), ( 13) (14) is a drive circuit connected to the microcomputer (12),
(15) is a relay connected to the drive circuit (13), which is a compressor (1)
It has a contact (15a) for turning on and off. Reference numeral (16) is a light emitting diode connected to the drive circuit (14) and is incorporated in the bidirectional thyristor (17) connected to the fan (3). (18)
Is a capacitor connected to the fan (3), (19) is a discharge resistor connected in parallel with the capacitor (18), (20) is a transformer connected to the power supply (6), (21) is a transformer (20) Is a waveform shaping circuit that is connected to the circuit to generate a pulse.

In the refrigerator controller constructed as described above, when the drive circuit (13) is operated by the command of the microcomputer (12) and the relay (15) is energized, the contact (15a) is opened. Turned on and the compressor (1) rotates. On the other hand, the output of the thermistor (4) is input to the microcomputer (12), the fan rotation speed determination means (8) determines the rotation speed of the fan (3) by the detected temperature,
The light emitting diode (16) is driven through the drive circuit (14).
With this, the conduction phase angle of the bidirectional thyristor (17) is controlled, and the rotation speed of the fan (3) is controlled.

Next, the operation of the power supply frequency determining means (8)
This will be described with reference to FIGS. Transformer (20) is the power supply
The voltage of (6) is transformed and the power supply waveform (31) is output. Waveform shaping circuit (21) pulse (32) at zero crossing point of power supply waveform (31)
Is generated and sent to the microcomputer (12).

If the power source (6) is turned on at time t ₁ , the timer is started in step (41). Step (4
In step 2), the timer S waits for a certain time T _s to elapse, and in step (43), the rising edge of the pulse (32) is detected. If the timer is not counting in step (44), the timer is started, the process returns to step (42), and the above steps are repeated. If the timer is counting, step (4
Proceeding from step 4) to step (46), the number of pulse edges detected above is counted.

In step (47), it is judged whether or not the count number is a prescribed number. If it is less than the prescribed number, the process returns to step (42) and the above steps are repeated. When the count reaches the specified number,
The time T _p of the timer is checked in step (48), the timer is stopped in step (49), the timer is cleared in step (50), and the process returns to step (42). Where the timer time T
_{From p} , the frequency of the power supply (6) is determined as follows: T _p ≦ 9 msec × count number ... 60 Hz T _p > 9 msec × count number ... 50 Hz.

In this way, by delaying the start of the detection of the power supply frequency by a fixed time T _s after the power is turned on, the judgment of the power supply frequency is started after the unstable state of the power supply (6) at the time of turning on the power is finished. Therefore, false detection of the power supply frequency is eliminated.

Embodiment 2 FIG. 5 and 6 show the second aspect of the present invention.
5 is a waveform diagram for explaining the operation, FIG. 6 is an operation flowchart, and the same parts as those in the first embodiment are denoted by the same reference numerals. 1 and 2 are also used in this embodiment.

Steps (41)-(45) are the same as in FIG.
When it is judged that the timer is counting in step (44), the time T _p of the timer is checked in step (55). This time T _p corresponds to a half cycle of the power supply waveform (31) in this embodiment. The timer is stopped in step (56), and the timer is cleared in step (57). Here, the frequency of the power source (6) is determined from the timer time T _{p as} follows: T _p ≦ 9 msec × count number ... 60 Hz T _p > 9 msec × count number ... 50 Hz.

In order to do this a specified number of times, the number of pulses is counted in step (58) and the number of pulses is checked in step (59). If it is repeated a prescribed number of times, it is judged in step (60) whether or not the results are all the same. If they are not the same, the process returns to step (41) and the same step is repeated again. If they are the same, the final power supply frequency is determined by the above determination.

By thus checking the power supply frequency a plurality of times to determine the final power supply frequency, even if the waveform is disturbed by noise or the like during the power supply frequency check, the power supply frequency will be stable. Can be determined.

[0021]

As described above, in the first invention of the present invention, the detection start timing of the power supply frequency is delayed by a certain time from the power-on, so that the power supply frequency is determined after the power supply waveform stabilizes. This has the effect of eliminating erroneous detection of the power supply frequency.

Further, in the second invention, the interval of each pulse is measured a plurality of times, and when the results are all the same, the power supply frequency is determined. Therefore, if there is an abnormality in the waveform during the measurement, the power supply is The frequency is not determined, and the power supply frequency can always be stably determined.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing a first embodiment and a second embodiment of the present invention.

FIG. 2 is a circuit diagram of the control device shown in FIG.

FIG. 3 is a waveform chart for explaining the operation of the first embodiment of the present invention.

FIG. 4 is an operation flowchart showing the first embodiment of the present invention.

FIG. 5 is a waveform diagram for explaining the operation of the second embodiment of the present invention.

FIG. 6 is an operation flowchart showing a second embodiment of the present invention.

[Explanation of symbols]

 1 Compressor 3 Fan 6 AC Power Supply 7 Control Device 8 Power Supply Frequency Determining Means 10 Control Means 12 Microcomputer 21 Waveform Shaping Circuit

Claims (2)

(57) [Claims] 1. An apparatus for providing a fan for circulating cold air generated by a refrigerating cycle, detecting a power supply frequency, and controlling a rotation speed of the fan by phase control,
A control device for a refrigerator, comprising: a power supply frequency determining means for delaying the power supply frequency detection start time from the power-on time by a predetermined time. 2. A fan for circulating the cold air generated by the refrigeration cycle is provided, and the power supply waveform is shaped into a pulse,
In a device for controlling the rotation speed of the fan by phase control by detecting the power supply frequency from the pulse interval, the power supply frequency detection start timing is delayed for a certain period from when the power is turned on, and the interval of each pulse is set a plurality of times. A control device for a refrigerator, comprising a power supply frequency determining means for measuring and determining the power supply frequency when all of the intervals are the same.