JPS62104483A - Ac/dc power source switching device - Google Patents

Abstract

PURPOSE:To enable operation with either power source AC or DC by supplying the power of predetermined frequency to a compressor through a switching element when the DC power source is connected, and using an AC voltage output to a transformer when the AC power source is connected. CONSTITUTION:When an AC power source voltage is applied to a terminal board 31, an AC power is supplied through a transformer 4. Simultaneously, an AC voltage is supplied to windings 4-1, 4-2, and a controller 1 to which the AC voltage is applied turns OFF switching elements TR1, TR2. The controller 1 drives a relay 33 on the basis of temperature detected by a temperature detector 2 to open or close a contact K to control the supply of an AC current to a compressor 5. When the DC power source voltage is supplied to a terminal board 30, the elements TR1, TR2 are turned ON, OFF by the controller 1, the AC current is supplied to the compressor 5 through a transformer 4, and the contact K is controlled to be opened or closed by the detector 2.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Applications) The present invention is directed to an AC/DC power supply switching device, particularly a compressor drive control device that drives a compressor with a drive power source that matches the resonance frequency of a vibrating compressor. In order to drive the compressor drive control device in both the AC and DC modes, the AC/DC power supply switching device is configured to operate the AC and DC power supplies respectively.

(Prior Art) There is a refrigerator that compresses and liquefies a gaseous refrigerant using a vibrating compressor and performs cooling etc. using the heat of vaporization when the liquefied refrigerant evaporates. Conventional.

As an example of a vibration type 11-compressor drive control system used in the refrigerator, there is a system as shown in FIG. In FIG. 8, the vibrating compressor 5 has a switching transistor T.
R,, TR2 is coming i1! DC by switching alternately to + state? iiΔ(() is applied alternately to the primary windings of the transformer 2:(4) with different polarities, and the drive is controlled so that a resonance state, that is, maximum efficiency is obtained.At this time, the switching transistor T R.

For example, TR2 is No. 1! The conductive state/non-conducting state is changed to an alternating current (L) in a manner similar to the small current waveform shown in Figure 1, and the switching frequency is controlled to match the frequency of the vibrating compressor 5. Ru. In detail,
In FIG. 9, a base current "I8" is alternately supplied from the drive circuit 1-3 to the bases of the switching transistors TR1 and TR2 so that the collector current "'Ic" is switched. In other words, the current waveform is shown as a current waveform obtained by multiplying the base current "■8" by the current amplification factor "hFE".
By supplying a so-called trapezoidal waveform as shown in Fig. 1, the switching transistors TR, TR2 are turned on/off by providing the condition ゎ≧hFEXIB at points P and P3 in the middle of Figure 1, respectively. The power source is switched alternately to obtain a driving power source of the desired frequency. Conventionally, as explained above, the vibrating compressor 5 has been driven using a drive power source that matches the resonant frequency of the compressor 5.

By the way, the circuit of the conventional AC/DC power supply switching device for a vehicle-mounted refrigerator that supplies a driving power source matching the resonant frequency of the vibrating compressor 5 to the compressor 5 is as follows.

As shown in FIG. 7, a configuration was adopted in which the power was manually switched depending on the power input to the terminal boards 30 and 31. When the compression a5 is driven by the DC power input from the Zunawa'EI Oat daughter plate 3o, the DC anode is connected to the mechanical thermostat 192. Through the winding of the transformer 4 the transistor Tl? , TR, and the cathode of the DC current is applied to the collector side of the transistor TR, ,' through the breaker 93.
It is applied to the emitter side of T'R2.

Outputs Q and Q are alternately generated from the control circuit section 91 at a predetermined frequency to the switching transistor TR.

TR2 is alternately switched between a conductive state and a non-conductive state,
An alternating current voltage having the resonant frequency of the compression a5 is generated in the winding of the transformer 4 on the compression m5 side. The compressor 5 was driven and controlled by the alternating current voltage so that it was in a resonant state, that is, maximum efficiency was obtained.

On the other hand, in the case of an AC power source that is manually powered from the terminal board 31, the AC power is supplied to the transformer 4 via a mechanical power source 92.
The AC voltage generated on the compressor a5 side of the transformer 4 drives the compressor 5 in a resonant state similar to that of a dielectric power source.

(Problems to be Solved by the Invention) In the circuit of the conventional AC/DC power supply switching device of a vehicle-mounted refrigerator, there are cases where the control circuit section is electronicized, or when a highly accurate electronic thermostat is used instead of a mechanical thermostat. When driven by AC power.

There was a drawback that DC voltage to operate these devices could not be obtained. In addition, in the case of a mechanical thermostat, it must be separated into two circuits, one for AC and one for DC, which means that it cannot be used as a single circuit for both AC and DC, which has the disadvantage of increasing costs.

In addition, since a large current flows in the direct current type of the mechanical thermostat, there is a drawback that it is necessary to use a device with a large contact capacity.

The present invention is aimed at solving the above-mentioned drawbacks, and is intended to provide an in-vehicle refrigerator that operates by manually switching between AC and DC using a terminal board. The object of the present invention is to provide an AC power switching device that can supply power.

(Step 11 to solve the problem) Therefore, the AC/DC power supply switching device of the present invention is provided.

Predetermined 1. corresponding to the load. ', in a pressure jliia drive control device 6 that drives and controls a vibrating compressor using one wave number.

The drive power generation section includes a drive power generation section that generates a drive power supply of a predetermined frequency, and the drive power generation section has an output Q of the predetermined frequency.
A) A switching control circuit for oscillating Q is provided, and a transformer is provided in which current alternately flows through the output 01 of the switching control circuit to supply alternating current power at a predetermined frequency to the compressor described in 016. The compressor drive control device controls the switching control circuit described in 1-1 to the operating state when DC power is applied to the compressor drive control device, and AC power is applied to the compressor drive control device. When the oscillation output Q of the switching control circuit, the AC/DC discriminator circuit that shuts off the power supply, and the detected λμ degree of the suction refrigerant temperature detector become below the indoor set temperature of the on-vehicle refrigerator, the above transformer is activated. a relay circuit that cuts off the voltage on the compressor side of the transformer; a rectifier that rectifies the AC voltage generated on the switching element side of the transformer when the compressor drive control unit 11 is operated with an AC power supply; A stabilized power supply section is provided that stabilizes the rectified DC voltage and supplies DC power to each circuit section provided in the drive power supply generation section, and when operating with the DC power supply, a switching element that is switched alternately is provided. supply power at a specified frequency to the compressor.

When operating on an AC power source, the AC voltage generated on the switching element side of the transformer is used to obtain DC power to each circuit section.

(Example) This will be explained below with reference to the drawings.

FIG. 1 shows the configuration of an embodiment of the AC/DC power switching device according to the present invention, FIG. 2 shows the configuration of an embodiment of the part of the control circuit according to the present invention, and FIG. 3 shows the configuration of a vehicle refrigerator to which the present invention is applied. A schematic configuration diagram, FIG. 4 is a circuit configuration of an embodiment of an on-vehicle refrigerator in which the present invention is used.

FIGS. 5 and 6 show other embodiments of the configuration of an AC/DC determining circuit that determines which driving power source, AC or DC, is applied.

Before explaining the AC/DC power switching device 6 according to the present invention.

The outline of the H1f Saikawa refrigerator in which the present invention is used and the circuit configuration in which the present invention is used will be explained.

In FIG. 3, 1 is a control circuit, 1-1 is a temperature detection section,
1-2 is a 6II calculation unit, and I-3 is a drive circuit.

2.3 is the temperature sensor, 4 is the moon-Jul, and 5 is the compressor.

6 represents a condenser, 7 represents a pressure reducer, 13 represents a refrigerator, and 8-1 represents an evaporator.

In the figure, control circuit 1, temperature detection section 1-1. Composed of arithmetic unit ■-2 and drive circuit 1-3, compressor 5
A temperature detector (T3) 2 detects the temperature corresponding to the saturated vapor pressure of the refrigerant sucked in by the compressor a5, and a temperature detector (rd) detects the temperature corresponding to the saturated vapor pressure of the refrigerant compressed and discharged by the compressor a5. 18 from 3 °C for supplying a drive signal of such a frequency that the compressor 5 is driven in resonance. Note that the temperature detected by the temperature detection unit 1-1 can be considered to be a temperature that substantially corresponds to the pressure of the refrigerant on the suction side and the pressure of the refrigerant on the discharge side.

A vibrating compressor 5 supplied with drive power generated by a drive signal supplied from the control circuit 1 compresses the refrigerant and supplies a mixture of gas and liquid to the condenser 6. It emits heat and liquefies it. Then, the liquefied refrigerant is vaporized in an evaporator 8-1 provided in the refrigerator 8 via the pressure reducer 7, and cools the refrigerator 8 by removing the heat of vaporization. The refrigerant that has absorbed the heat of vaporization is compressed again by the compressor 5. By repeating the clost cycle as described above, the evaporator 8-
The heat taken away from the condenser 6 will be released in the form of heat from the condenser 6. The operation of the control circuit 1 will be described in detail below.

In the figure, a temperature detection section 1-1 is for converting signals detected by temperature detectors (eg, thermistors) 2 and 3 into predetermined electrical signals.

In the figure, the arithmetic unit 1-2 outputs "temperature corresponding to suction pressure" and "
This is to generate a voltage corresponding to the frequency at which the compression m5 is driven in a resonant state based on the temperature corresponding to the discharge pressure. and.

The drive circuit 1-3 supplies a drive No. 13 with a frequency corresponding to the voltage supplied from the arithmetic unit 1-2 to the transistors TR and TR2 in the figure, and outputs a DC power supply V (shown in the figure).
(The transformer 4Q) supplies current to the primary winding of the transformer 4 in the form of a rectangular wave in which the polarity alternately switches between the windings. The AC voltage obtained from the next winding is supplied to the compressor 5, and the compressor 5 is always driven in a resonant state, i.e., driven at maximum efficiency.

In the circuit configuration of an embodiment of a vehicle refrigerator in which the present invention is used in FIG. 4, reference numeral 1-1. ■-2, 13, 2 to 5. , TR2 are the same as those shown in FIG. 3, so their explanation will be omitted.

Reference numeral 9 is a thermo device, l (14, 1+- a turbocharger temperature comparator, 13 is a surge absorption circuit, 24 is a volume, 25 is a shunt, 21i, 2!1 are diodes.

30 and 31 are terminal plates, 32 is a DC detection circuit, 33 is a relay, and 34 is a diode.

The thermo device 9 is for setting the indoor temperature of the refrigerator, and the volume 2 provided in the thermo device 9 is
The indoor temperature of the refrigerator changes depending on the setting of 4.

The evaporator temperature comparator 10 uses the signal of the indoor temperature of the refrigerator set by the volume 24 and the evaporator 8-
The signal from the temperature detector 2 which detects the temperature of the thermometer 1 is electrically compared with the signal from the temperature detector 2, and when the set temperature of the 9 thermostats becomes higher than the temperature of the evaporator 8-1 side, the logic "■," is activated. Output. The output of the logic rLJ becomes a stop signal to the drive circuit 1-3 via the OR circuit 20 having a negative input terminal, and also opens the contact K of the relay 33 via the diode 34, thereby causing the relay 33 to open. The supply of AC voltage to the compressor 5 connected to the contact K is cut off.

The surge absorption circuit 13 absorbs the surge voltage of the input DC power supply and supplies the DC power to the drive circuit 1-3.The surge absorption circuit 13 also outputs a logic "I ]” is output. The logic r I-
IJ is connected to the drive circuit 1-3 via the OR circuit 19 to the transistor TR.

The output of TR2 is controlled to 1-rule, and the stroke of compressor 5 is controlled.

The overcurrent detection circuit 14 detects an overcurrent flowing through the transistors TR, TR2 together with the transistors 71-25. When the overcurrent detection circuit 14 detects an overcurrent, it sends the transistors TR, TR, and TR2 to the drive circuit 1-3. , TR2 outputs an output off launch signal to stop the operation of -0 transistor TR,.

Prevent damage to T R2, etc.

The DC detection circuit 32 is a circuit that detects whether DC voltage is applied to the terminal board 30, and outputs logic rLJ when DC voltage is applied to the terminal board 30, and outputs logic rLJ when no DC voltage is applied. That is, when the compressor 5 is driven by the AC voltage applied to the terminal plate 31, the logic rHJ is output. The logic [■]'' becomes a stop signal to the drive circuit 1-3 via the OR circuit 2o. That is, the DC detection circuit 32 is an AC/DC discrimination circuit that determines whether AC power or DC power is applied.

Next, the present invention will be explained in more detail using FIGS. 1 and 2.

In FIGS. 1 and 2, the symbols ], , ]-1,2°4, . 5. TR+ and TRz correspond to those in Fig. 3.

10.28 to 33 correspond to those in FIG.

Code 4. -1.4-2.4-3 is a winding, 35 is a switching control circuit, and 36 is a stabilized power supply section.

37 is an OR circuit, 38 and 39 are transistors, 40 is a diode, and 41 to 43 are resistors.

When AC power supply voltage is applied to the terminal board 31.

AC power is supplied to the compressor 5 via the transformer 4 .

At the same time, an alternating current voltage is generated in the windings 4-1, 4-2. This AC voltage is full-wave rectified by diodes 28 and 29, and converted into a stabilized DC voltage by a stabilized power supply section 36. When driven by applying AC power, this stabilized DC voltage is supplied to each circuit. For example, to the DC detection circuit 32 that determines the applied power (J (supplied),
Since no curved current power is applied to the terminal board 30 from the DC detection circuit 32, the logic "■1" is outputted at 111. The logic [HJ is input to the switching control circuit 35 via the OR circuit 37, and the switching transistors TR,
, stops the oscillation of the control output 02 stone to TR2. Further, for example, a DC voltage is supplied to an electronic thermo device 9. The evaporator temperature comparator 10 electrically converts the indoor temperature signal of the refrigerator set by the volume 24 provided in the thermostat 9 and the signal from the temperature detector 2 which detects the temperature of the evaporator 8-1. When compared, when the temperature on the evaporator 8-1 side and the indoor temperature of the Zunawara cold storage are lower than the indoor temperature set by the thermometer 9, a logic "I," is output. The logic [-L] is the transistor 3
The relay ;) 3 is driven through 8 and its contact K is opened. As a result, the supply of AC voltage to the compressor 5 is cut off, and the operation of the refrigerator is stopped. Therefore, the indoor temperature of the refrigerator is maintained at the temperature set by the thermo device 9.

Note that the logic “L” from the evaporator temperature comparator 10
is also input to the switching control circuit 35 via the OR circuit 37 having a negative input terminal, and stops the oscillation of the control outputs Q and Q to the switching transistors TRI and TRz.

On the other hand, when a DC power supply voltage is applied to the terminal board 30, the DC voltage is supplied to each circuit via the stabilized power supply section 36. At this time, the operation of the evaporator temperature comparator 10 is exactly the same as when the AC power supply voltage is applied.

At this time, the DC detection circuit 32 outputs the logic rLJ, but the stabilized power supply section 36 cannot determine whether the DC power supply voltage or the AC power supply voltage is being applied to the control circuit 1. . Therefore, as shown in FIG. 1, the terminal board 30 to which DC power is applied has a three-terminal structure, and the anode is short-circuited within the terminal board 30 to form two terminals. When the terminal board 30 is used, When a DC power supply voltage is applied, one of the two anode terminals is used for DC voltage detection. As a result, when a potential is applied to the anode line A, it is converted to a level by the DC detection circuit 32, and when a DC power supply voltage is applied as described above, the DC detection circuit 32 outputs a logic "■," indicating the application of a DC voltage. It's coming. Conversely, when no DC power supply voltage is applied, that is, when AC power supply voltage is applied, the DC detection circuit 3
2, the logic is applied and the distinction between AC and DC power sources is determined.

FIGS. 5 and 6 show other embodiments of an AC/DC determining circuit that determines which drive power source, AC or DC, is applied.

In FIG. 5, a current detection element 4 is connected to an AC power line 46.
4 is provided, and when the AC power supply voltage is applied to the terminal plate 314j, the current detection element γ44 detects the AC current flowing in the AC power supply line 4G, and the amplifier 45 amplifies the AC current appropriately to obtain an AC detection signal. This is an AC power supply voltage discrimination circuit. As the current detection element 44, for example, a current transformer,
Ball ■c etc. are used.

In FIG. 6, a relay 48 is provided at both ends of the DC power supply voltage, and its contacts are connected between the winding of the transformer 4 and the terminal plate 47, and the DC voltage is applied from the anode side of the terminal plate 47 to the DC detection circuit 32. This is a DC power supply voltage discrimination circuit configured to input as a detection signal.

When a DC power supply voltage is applied to the terminal plate 47, the anode of the DC voltage is input to the DC detection circuit 32, and the logic rLJ
is output. Further, the contact of the relay 48 is turned on, and DC voltage is supplied to the transformer 4.

Needless to say, the AC power source and the DC power source are used exclusively, and if necessary, a configuration may be provided in which one can be used only when used exclusively.

(Effects of the Invention) As explained above, according to the present invention, an on-vehicle refrigerator can be operated using any of the five AC and DC power sources. In the AC type drive, DC power can be supplied to the control circuit, and an electronic thermostat can be used.
'1 An electronic thermostat can be used in common for both power sources, and only one can be used.

Since the drive power is turned on and off on the compressor 5 side, the contact capacity for opening and closing is small.

Also, you will be able to do a reasonable job with a single-pole, single-throw relay.

[Brief explanation of drawings]

FIG. 1 shows the configuration of an embodiment of the AC I [1 power supply switching device according to the present invention, FIG. 2 shows the configuration of an embodiment of the part of the control circuit according to the present invention, and FIG. A schematic configuration diagram of a refrigerator, FIG. 4 is a circuit configuration of an embodiment of a vehicle refrigerator in which the present invention is used, and FIGS. 5 and 6 are AC/DC discrimination for determining which driving power source is applied. Another example configuration of the circuit, FIG. 7 is an example of a conventional AC/DC power switching device for an on-vehicle refrigerator, FIG. 8 is an explanatory diagram explaining a conventional compressor drive control system, and FIG. An operation explanatory diagram illustrating the operation of the illustrated compressor drive control method is shown. In the figure, 1 is a control circuit, 1-1 is a temperature detection section, ■-2 is a calculation section, 1-3 is a drive circuit, 2 and 3 are temperature detectors, and 4
is a transformer, 5 is a compressor, 6 is a condenser, 7 is a pressure reducer, 8 is a refrigerator, 8-1 is an evaporator, 28.29 is a diode, 30.31 is a terminal board, 32 is a DC detection circuit, 33 is a The relay, 35 is a switching control circuit, and 36 is a stabilized power supply section.

Claims (1)

[Claims] A compressor drive control device that controls the drive of a vibrating compressor using a predetermined frequency corresponding to a load, which includes a drive power generation section that generates a drive power supply of a predetermined frequency, and the drive power generation section includes the above-mentioned drive power generation section. It is equipped with a switching control circuit that oscillates outputs Q and @Q@ of a predetermined frequency, and current alternately flows through the outputs Q and @Q@ of the switching control circuit to supply alternating current power of a predetermined frequency to the compressor. A compressor drive control device comprising a transformer that controls the switching control circuit to be activated when DC power is applied to the compressor drive control device, and when AC power is applied to the compressor drive control device. an AC/DC discrimination circuit that stops the oscillation output Q, @Q@ of the switching control circuit when a relay circuit that disconnects the voltage on the compressor side of the transformer; a rectifier that rectifies the AC voltage generated on the switching element side of the transformer when the compressor drive control device is operated with an AC power source; A stabilized power supply section is provided, which stabilizes the DC voltage generated and supplies DC power to each circuit section provided in the drive power supply generation section. An AC/DC system that supplies power at a predetermined frequency to the machine, and when operating on AC power, uses the AC voltage generated on the switching element side of the transformer to obtain DC power to each circuit section. Power switching device.