JPH06288388A - Compressor driving power source device - Google Patents

Abstract

PURPOSE:To surely start a compressor without enlarging a transformer even when voltage is easily fluctuated in an area having a power source voltage different from the interior. CONSTITUTION:A general tap 4a and an auxiliary tap 4b are provided on the primary side of a transformer 4, and connected to a power source side through a change-over switch 7. A compressor 3 is connected to the secondary side of the transformer 4 through a relay switch 8. On the basis of the temperature detection signal from a temperature detecting circuit 11, a microcomputer 13 carries a current to a relay coil 15 to switch the auxiliary tap 4b to the connected state when the compressor 3 is driven, and gives a voltage higher than the general power source voltage to the compressor 3. Even when the power source situation is bad, and an excessive starting current is carried to the compressor 3 to lower the voltage, the minimum starting voltage necessary for the starting can be ensured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor driving power supply device capable of reliably starting a compressor even in an environment where the power supply voltage is apt to change.

[0002]

2. Description of the Related Art For example, in a cooling device installed in a refrigerator, a cooling operation is performed by compressing a refrigerant by a compressor. In this case, the compressor is driven by an AC input of 100V which is a power supply voltage in Japan.

In recent years, there are some refrigerators designed according to the specifications for domestic use so that they can be used by converting the power supply voltage to 100 V even in areas where the power supply voltage is different. In this device, a transformer is interposed in the input part of the power supply voltage, and in the power supply voltage region of 200 V, for example, by adjusting the ratio of the number of turns of the primary winding and the secondary winding, 100 V is supplied to the secondary side. The voltage is output.

[0004]

However, in such an area where the power supply voltage is different, the power supply situation is bad and the voltage may drop due to the large impedance of the power supply line when the used current becomes large. .
As described above, when a transformer converts the power supply voltage to supply power to the compressor, if a large current of about 10 times that in the steady state flows at the time of startup, under such power supply conditions, the power supply line and the transformer are changed. The voltage drop due to the impedance of the device becomes large, so that there is a possibility that the minimum starting voltage required for starting the compressor cannot be secured and the compressor cannot be started.

Therefore, for example, in order to reduce the voltage drop of the transformer, the impedance can be lowered by increasing the diameter of the winding. However, in this case, the transformer becomes large and the weight becomes large. Since it increases, it is actually unsuitable for attaching to a refrigerator.

The present invention has been made in view of the above circumstances, and an object of the present invention is to reliably start a compressor even when the power supply voltage fluctuates to fall below a minimum starting voltage required for starting the compressor. The present invention provides a power supply device for driving the compressor.

[0007]

A compressor driving power source device of the present invention is provided as a power source for a compressor, and converts a predetermined primary side voltage into a rated input voltage of the compressor and
A transformer having a normal tap that is output to the secondary side and an auxiliary tap that is converted to a voltage higher than the rated input voltage of the compressor and that is output to the secondary side; Upon receiving a start signal to the switching means and a switching means for switching from the connected state to the connected state of the auxiliary tap, the tap switching signal is output to the switching means for a predetermined time, and the tap switching signal is output during the output period. It is characterized in that it is provided with a control means for starting the compressor.

[0008]

According to the compressor driving power supply device of the present invention, when the control means receives the start signal of the compressor, the control means outputs the tap switching signal to the switching means for a predetermined time so that the taps of the transformer are switched from the normal taps. Switch to the auxiliary tap, start the compressor so that the input voltage to the compressor is higher than normal, and after a certain period of time, return the transformer tap to the connection state to the normal tap and continue driving. become.

As a result, a high input voltage can be applied to the compressor at start-up, even if the power supply situation is bad and the voltage drops, for example. You will be able to reliably start.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a compressor for a refrigerator cooling device will be described below with reference to the drawings. FIG. 2 is a schematic view showing the rear part of the refrigerator 1, in which a machine room 2 is provided in the lower part, and a compressor (compressor) 3 and a transformer 4 which configure a refrigeration cycle are provided in the machine room 2. The primary side of the transformer 4 is connected to the power source plug 5, and the secondary side is connected to the compressor 3 and the control circuit unit 6. The control circuit section 6 controls the energization of the compressor 3 and also controls each section in the refrigerator 1, and is arranged on the upper rear surface. In addition,
The compressor 3 can be driven by an input voltage of 100 V AC, which is a domestic specification.

FIG. 1 shows an electrical configuration of a portion related to energization control to the compressor 3. The transformer 4 has a single-turn coil, and the primary side, which is the high-voltage side, usually has a tap. 4a and auxiliary tap 4b are provided. The normal tap 4a and the auxiliary tap 4b are provided with a changeover switch 7
Is connected to the power plug 5 via. The secondary side, which is the low-voltage side of the transformer 4, is connected to the series circuit of the compressor and the relay switch 8. Normal tap 4a
Is 2 when the input voltage of 200V is given to the primary side.
The auxiliary tap 4b outputs a voltage of 100V to the secondary side, and when the input voltage of 200V is applied to the primary side, the auxiliary tap 4b outputs a voltage higher than the 100V by several V to the secondary side. Is configured.

In the control circuit section 6, when the DC power supply circuit 9 is fed from the secondary side of the transformer 4, it supplies a predetermined DC voltage to each section inside the circuit. The temperature detection circuit 10 detects the temperature in a freezer compartment (not shown) of the refrigerator 1, and connects a temperature sensor (for example, a thermistor) 11 and a resistor 12 in series and is connected between the DC power supply terminal VD and the ground. ing. Microcomputer 13 as control means
Controls the switching on and off of the compressor 3, and its input terminal A is connected to the output terminal of the temperature detection circuit 11.

Output terminal B of the microcomputer 13
Is connected to the DC power supply terminal VC via the inverter circuit 14 and the relay coil 15 in series. The relay coil 15 turns on the above-mentioned changeover switch 7 in its energized state.
The connection state of the normal tap 4a is switched to the connection state of the auxiliary tap 4b, and a diode 16 having the illustrated polarity is connected in parallel to this. The output terminal C of the microcomputer 13 is the inverter circuit 1
7 and the relay coil 18 are connected in series to the DC power supply terminal VC. The relay coil 18 is adapted to turn on the above-mentioned relay switch 8 in its energized state, and a diode 19 having the illustrated polarity is connected in parallel to this.

Next, the operation of this embodiment will be described with reference to FIGS. 3 and 4. The change-over switch 7 is set so that the normal tap 4a of the transformer 4 is connected at a normal time when the relay coil 15 is not energized. When the power supply plug 5 supplies a power supply voltage of 200 V, for example,
Normally, a voltage of 100V is output to the secondary side via the tap 4a. In this state, the DC power supply circuit 9
Outputs a predetermined voltage to the DC power supply terminals VD and VC in the control circuit section 6 to supply power to each section.

In the operating state of the refrigerator 1, the microcomputer 13 detects when the detected temperature T indicated by the temperature detection signal given to the input terminal A from the temperature detection circuit 11 becomes equal to or higher than the predetermined temperature level Ts (FIG. 3 (a)). ), The compressor 3 is driven to operate the cooling device. At this time, the microcomputer 13 first
The "H" level tap switching signal S1 is output to the output terminal B, and after a predetermined delay time (for example, 10 msec) elapses, the "H" level drive signal S2 is output to the output terminal C.
Will be output.

When the "H" level tap switching signal S1 is output from the output terminal B of the microcomputer 13 (see FIG. 3B), the output terminal of the inverter circuit 14 is inverted to the "L" level. Therefore, the relay coil 15 is energized from the DC power supply terminal VC. As a result, the changeover switch 7 switches the connection state of the normal tap 4a to the connection state of the auxiliary tap 4b. Then, a higher voltage is output to the secondary side of the transformer 4 than when the normal tap 4a is connected.

When the start signal S2 of "H" level is output from the output terminal C of the microcomputer 13 (see FIG. 3C), the output terminal of the inverter circuit 17 is inverted to "L" level. As a result, the relay coil 18 is energized from the DC power supply terminal VC. As a result, when the relay switch 8 is turned on, the compressor 3 is supplied with the output voltage from the secondary side of the transformer 4.

When the compressor 3 is energized, a considerably larger level of starting current flows than in the steady state, and in a situation where the power supply situation is bad, the voltage drop due to the high impedance of the power supply line causes the power supply voltage to drop. May decrease. However, at this time, since a high voltage is output to the secondary side of the transformer 4 due to the connection of the auxiliary tap 4b, for example, the auxiliary tap 4b is provided so that the minimum starting voltage Vmin required for starting the compressor 3 can be secured.
If is set, it becomes possible to reliably start the compressor 3.

For example, as shown in FIG. 4, when the power supply voltage is applied to the primary side of the transformer 4 via the normal tap 4a, the value of the power supply voltage becomes constant in the steady state. Accordingly, it can be seen that the output voltage shown by the solid line is obtained on the secondary side. Then, when the output voltage on the secondary side is reduced to the level shown by the thin broken line in the figure when the compressor 3 is started, the output voltage shown by the thick broken line in the figure is obtained in the connected state of the auxiliary tap 4b. Shows.
The output voltage of the auxiliary tap 4b is 90V which is the minimum starting voltage Vmin required for starting the compressor 3 even when the fluctuation of the input power supply voltage is reduced to 180V.
The voltage in the vicinity can be secured, and the system can be started reliably. Note that FIG. 4 shows the guaranteed range (200 V ± 10%) of the input voltage of the transformer 4 with respect to the voltage range (100 V ± 10%) that guarantees the operation of the compressor 3.

When the compressor 3 is activated,
When, for example, about 10 seconds elapse until the energized current reaches the steady-state current level, the microcomputer 13
Resets the output of the tap switching signal S1 to the "L" level (see FIG. 3B). As a result, the changeover switch 7 changes from the connection state of the auxiliary tap 4b to the normal tap 4a.
Now the connection state of the transformer 4 is restored, and the transformer 4 is the normal tap 4
The power supply voltage is received via a and converted to a predetermined voltage and output to the secondary side.

At this time, since the compressor 3 is in a steady state and the energizing current is stable at a normal level, the compressor 3 has been recovered from the reduced state of the power supply voltage. Therefore, the compressor 3 is provided on the secondary side of the transformer 4. It will be possible to supply the voltage required to drive the.

According to this embodiment, when the compressor 3 is started up, the microcomputer 13 outputs the tap changeover signal S1 to the changeover switch 7 to change over to the connection state of the auxiliary tap 4b of the transformer 4 and then the compressor. Since 3 is energized to start, even if an excessive starting current flows through the compressor 3 and the power supply voltage drops, a high starting voltage is applied to the compressor 3 in advance, so a minimum starting voltage Vmin is secured. It is possible to start it surely. As a result, it is possible to realize a configuration in which the compressor 3 is reliably started even in different power supply voltage regions, without making the transformer 4 large in size, and as a simple configuration.

In the above embodiment, the normal tap 4a and the auxiliary tap 4b are provided on the primary side of the transformer 4, but the present invention is not limited to this, and may be provided on the secondary side, for example. . Further, in the above-described embodiment, the output time of the tap switching signal S1 is set to about 10 seconds, but the output time is not limited to this, and can be appropriately set according to the time during which the operating state of the compressor is in the steady state, Further, the output timing of the compressor start signal S2 is also set to 10 msec as the delay time after the output of the tap switching signal S1, but if the time necessary to switch from the normal tap 4a of the transformer 4 to the auxiliary tap 4b can be secured, it is appropriate. Can be set to. .

[0024]

As described above, according to the power source device for driving the compressor of the present invention, the transformer having the normal tap and the auxiliary tap for the primary side voltage is provided, and the control means at the time of starting the compressor. Since the tap switching signal is given to the switching means to switch to the connection state of the auxiliary tap, even if the primary side voltage drops when an excessive starting current flows by energizing the compressor, Since it can be driven by applying a high voltage, it is possible to reliably start the compressor even in areas where the power supply situation is bad, without taking measures such as increasing the winding diameter of the transformer, while making it a simple configuration. It has an excellent effect that

[Brief description of drawings]

FIG. 1 is an electrical configuration diagram showing an embodiment of the present invention.

FIG. 2 is a schematic view showing a rear portion of the refrigerator.

FIG. 3 is a time chart showing a signal output state of each part.

FIG. 4 is an operation explanatory view showing the relationship between the input voltage and the output voltage of the transformer.

[Explanation of symbols]

1 is a refrigerator, 3 is a compressor (compressor), 4 is a transformer, 6 is a control circuit section (control means), 7 is a changeover switch (switching means), 8 is a relay switch, 10 is a temperature detection circuit, and 11 is temperature. Sensor, 13 is a microcomputer,
Reference numeral 15 is a relay coil, and 18 is a relay coil.

Claims (1)

[Claims] 1. A predetermined one provided as a power source of a compressor.
A normal tap for converting the secondary side voltage to the rated input voltage of the compressor and outputting it to the secondary side, and an auxiliary tap for converting it to a voltage higher than the rated input voltage of the compressor and outputting it to the secondary side. A transformer having a tap; switching means for switching the transformer from a connection state of a normal tap to a connection state of an auxiliary tap when receiving a tap switching signal; and a switching means for receiving a start signal to the compressor. A power supply unit for driving a compressor, comprising: a control unit that outputs a tap switching signal for a predetermined time and starts the compressor during an output period of the tap switching signal.