JPS596581B2 - AC/DC switching power supply - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an AC/DC switching power supply device, in particular an AC/DC switching power supply device that can drive a refrigerator compressor, for example, with an AC power source or a DC power source. The present invention relates to an AC/DC switching power supply device that is configured with a switch to prevent an inverter circuit from becoming undesirably activated during AC drive.

``Electric oscillating compressors are generally used in household refrigerators because they are small, lightweight, and have good operating efficiency, and are also used in refrigerators installed in cars, motor boats, etc. Refrigerator 1 When used in a refrigerator, a battery is used as the power source, so an inverter circuit is included to convert direct current to alternating current.

For this reason, an AC/DC switching power supply device that can be driven by either an AC power source or a DC power source is being considered as a power source device for the refrigerator compressor, and one example is the one shown in Fig. 1. .

In FIG. 1, 1 is a transformer, 2 is a refrigerator compressor, 3 is a thermostat that controls the temperature of the refrigerator cooled by the refrigerator compressor 2, and 4 is an inverter circuit.
5 is an output winding, 6 is an AC manual winding, 7 is a winding on the inverter output terminal side, 7-1 is an intermediate tap of the winding 7, 8 is a feedback winding, 9 is an AC drive circuit and a DC 1 10, 13, 16 are DC side contacts of the relay device 9, 11, 14, 17 are AC side contacts of the relay device 9, 12, 15, 18
denote movable contacts in the relay device 9, 19 a relay winding in the relay device 9, and C2 a smoothing capacitor for smoothing the fluctuating voltage applied to the inverter circuit 4, respectively.

When the refrigerator compressor 2 is driven by an AC power source, current is supplied to the relay winding 19 of the relay device 9 and the movable contact 12
, 15, and 18 are electrically connected to the AC side contacts 11, 14, and 17, respectively. Therefore, a circuit is formed from the terminal A shown on the AC power supply side through the AC input winding 6, the AC side contact 11, the movable contact 12, the thermostat 3, the movable contact 15, and the AC side contact 14 to the terminal A2 shown. , an AC voltage is supplied to the AC input winding 6. Then, an alternating current voltage is generated in the output winding 5 via the transformer 1, and the refrigerator compressor 2 is driven. On the other hand, when the compressor 2 is driven by a DC power source, the relay device 9 has DC side contacts 10,
13 and 16 are turned on, from the positive terminal of the DC power supply to the DC side contact 13, movable contact 15, thermostat 3,
A circuit is formed that connects the movable contact 12, the DC side contact 10, the inverter circuit 4, the inverter, and the intermediate tap J to the terminal P of the output terminal side winding 7 to the negative terminal of the DC power supply, and connects to the inverter circuit 4. The transistors TRl and TR2 alternately turn on and off, and an alternating current voltage is supplied to the winding 7 on the inverter output terminal side.

Then, an alternating current voltage is generated in the output winding 5 via the transformer 1, and the refrigerator compressor 2 is driven. As is well known, the feedback winding 8 is used to control switching between the transistor TR1 and the transistor TR2. Further, the DC side contact 16, AC side contact 17, and movable contact 18 of the relay device 9 are used to supply starting current to the transistors TRl and TR2 of the inverter circuit 4 when starting the compressor 2 with the DC power supply. belongs to. However, in this type of AC/DC switching power supply device, if a 100V commercial AC power supply is used as the AC power supply and a 12V battery is used as the DC power supply, the AC side contacts 11 and 14 of the relay device 9 An alternating current voltage of about 100 V is applied, and a direct current voltage of about 12 V is applied to the DC side contacts 10, 13, and the AC side contacts 11,
14 and the DC side contacts 10 and 13 are relatively narrow, especially during AC drive, the AC side contact 1
The withstand voltage between 1 and 14 and the 5 points 10 and 13 on the DC side is destroyed, causing electrical leakage, sparks, arcs, and other discharges, resulting in high voltage leaking to the DC drive circuit side of the low-voltage circuit, causing the risk of electric shock. There is sex.

The present invention aims to solve the above-mentioned problems, and aims to prevent the risk of undesired electrical leakage occurring in a relay device. The present invention will be explained below with reference to FIG. 2 and FIG. 3. FIG. 2 shows one embodiment of the AC/DC switching power supply device according to the present invention, and FIG. 3 shows another embodiment of the present invention. In Fig. 2, 20 is a relay device according to the present invention, 21, 22, 24, 25, 27, 28 are fixed contacts, 23, 26, 29 are movable contacts, 30 is a relay winding, and 31 is a fixed contact. 32 is a second receiving connector; 33 is a first plug-in connector; 34 is a second connector;
In the plug-in side connector, 35 is an insulating member, and other symbols correspond to those in FIG. 1, respectively. The relay device 20 is constructed of a device having on/off contacts with a relatively large gap between the contacts, such as an electromagnetic switch, for example. Further, the first and second receiving side connectors 31 and 32 are built into the main body case of the device so that, for example, each terminal bit 15b2 B3jb4jalja2ya3 protrudes outside, and the insulating member 35
For example, the connector 31 is attached to the main body case of the device opposite to the first and second receiving connectors 31 and 32.
, 32 is movable in both directions indicated by solid line arrows and dashed line arrows. When driving the refrigerator compressor 2 with an AC power supply, each terminal Al, a2, a3 of the second receiving side connector 32 and each terminal a/, ano, The second insertion side connector 34 is inserted into the second recipient side connector 32 so that Af is electrically connected.

As a result, current is supplied to the relay winding 30 of the relay device 20, the movable contact 23 short-circuits between the fixed contacts 21 and 22, and the movable contact 26 and the movable contact 29 short-circuit between the contacts 24 and 25, respectively. Then, the contact points 27 and 28 are opened. By causing the movable contact 23 to short-circuit between the fixed contacts 21 and 22, it is possible to connect one power terminal of the AC power source to the terminal a/ of the second plug-in connector 34 and the second receiving connector. 32 terminals A, AC input winding 6, fixed contact 21, movable contact 23, fixed contact 22, thermostat 3
, the terminal A2 of the second receiving connector 32, and the terminal AJ of the second plug-in connector 34 to form a circuit extending to the other power terminal of the AC power source. Therefore, an AC voltage is supplied to the AC input winding 6, and an AC voltage is generated in the output winding 5 via the transformer 1. The compressor 2 is driven by the AC voltage generated in the output winding 5. As is clear from the above, the thermostat 3 controls the power supply to the AC input winding 6. If you die during this AC drive,
The insulating member 35 is in the state shown by the broken line in the figure and shields the first receiving connector 31. On the other hand, when driving the refrigerator compressor 2 with a DC power supply, each terminal Bl, b2, b3, b4 of the first receiver side connector 31 and the first insertion side connector 3
The first insertion-side connector 33 is inserted into the first receiving-side connector 31 so that each terminal b/, bda, B3', and B4' of the three terminals are electrically connected.

On the other hand, in the relay device 20, the movable contacts 23, 26,
29 is in the state shown in FIG. That is, the movable contact 23 is in an OFF state, and the movable contacts 26 and 29 are both in an ON state. Therefore, when the first plug-in side connector 33 is inserted into the first receiving-side connector 31, the terminal B2' of the first plug-in side connector 33 and the terminal B2' of the first plug-in side connector 31, Terminal B2, parallel circuit of breaker and lamp, intermediate tap J of winding 7 on the inverter output terminal side
Yaw P, inverter output terminal side winding 7, inverter circuit 4, input terminal c of inverter circuit 4, fixed contact 27, movable contact 29, fixed contact 28, thermostat 3, fixed contact 25, movable contact 26, fixed contact 24, a circuit is formed that passes through the terminal b1 of the first receiving connector 31 and the terminal b/ of the first plug-in connector 33 to one terminal of the DC power supply. At the same time, the input terminal d and the manual terminal e of the inverter circuit 4 are the connection between the terminal B3 of the first receiving connector 31 and the terminal Bfj of the first plug-in connector 33, and the terminal B4 of the connector 31. and the terminal Bf of the connector 33 are connected to each other to short-circuit the terminal Bf.

Therefore, the transistors TRl and TR of the inverter circuit 4
2 is alternately turned on and off, and AC voltage is supplied to the winding 7 on the inverter output terminal side. Then, an alternating current voltage is generated in the output winding 5 via the transformer 1, and the refrigerator compressor 2 is driven. During this DC drive, the insulating member 35 is in the state shown by the solid line in the figure, and the second receiving connector 32
to shield. FIG. 3 shows another embodiment of the present invention, and in the case of this embodiment, the relay winding 30 of the relay device 20 is connected to the AC side input section, whereas in the embodiment of FIG. The relay winding 30 is connected to the DC side input section.

As a result, in the case of FIG. 2, the second plug-in connector 34
is inserted, but if the power supply to a/or a is stopped for some reason, the relay winding 30 will not be energized, and the AC and DC circuits will be shared through contacts 28, 29, and 27. A drawback is that a high AC voltage is applied to the low-voltage DC circuit. In the case of FIG. 3, the DC voltage is shared between the AC circuit and the DC circuit only when the first plug-in connector 33 is inserted, and the above drawback is eliminated. As described above, in the case of the present invention, unique connectors are used depending on whether a DC power source is used or an AC power source is used.

For this purpose, in the conventional case, the relay device 9 shown in FIG.
In the relay device, so to speak, 10
It was necessary to switch between 0VAC and 12VDC, but in the case of the present invention, the switching of the power supply itself is done by the relay device 20.
There is no need to do it inside. In addition, the relay device 20 is constructed of, for example, an electromagnetic switch with a relatively large gap between contacts, and the first and second plug-in connectors 33, 34}
and first and second receiving side connectors 31 and 32,
When using a DC power source, the first plug-in connector 33 is kept inserted into the first receiving connector 31 and the second plug-in connector 34 is disconnected from the second receiving connector 32. On the other hand, when using AC power, the first plug-in connector 33 is kept disconnected from the first receiving connector 31, and the second plug-in connector 34 is kept disconnected from the second receiving connector 32. I kept it in the inserted state.
This eliminates the risk of undesired leakage of AC voltage to the DC and drive side circuits, especially during AC 1 drive. Further, according to the present invention, since the insulating member 35 is configured to shield the first receiving connector 31 during AC drive and to shield the second receiving connector 32 during DC 1 drive, At times, it is possible to prevent accidents such as electric shock due to undesired voltage induced between the terminals of the first receiving connector 31 and between the terminals of the second receiving connector 32, respectively.

[Brief explanation of the drawing]

FIG. 1 shows an example of a conventional AC/DC switching power supply device, and FIGS. 2 and 3 each show an embodiment of the present invention.

Claims (1)

[Claims] 1. A transformer having an AC input winding, an inverter output terminal side winding, and a secondary winding, a load connected to the secondary winding,
a thermostat that controls the temperature of the load; an AC power supply connected to the AC input winding; an inverter circuit connected to the inverter output terminal side winding; a DC power supply that applies DC voltage to the inverter circuit; In an AC/DC switching power supply device having a smoothing capacitor connected between the DC voltage supply terminals and smoothing a fluctuating voltage when supplying the DC voltage to the inverter circuit, and a relay device, between the DC power supply and the inverter circuit. A first insertion side connector and a first receiving side connector are provided that can be inserted into and removed from each other, and a second insertion side connector that can be inserted into and removed from each other is provided between the AC power source and the AC input winding. A plug-in connector and a second receiving connector are provided, and the first plug-in connector and the first receiving connector are inserted into each other.
By disconnecting, the connection between the DC power source and the inverter circuit is turned on and off, and by inserting and disconnecting the second plug-in connector and the second receiving connector, the AC input winding is turned on and off. The relay winding of the relay device is configured to be energized by either the direct current power source or the alternating current power source, and the relay winding of the relay device is energized by either the direct current power source or the alternating current power source. The thermostat is characterized by having an on/off contact that connects the thermostat to the AC input winding when a power source is selected, and an on/off contact that connects the thermostat to a DC power supply circuit for the inverter circuit when a DC power source is selected. AC/DC switching power supply.