JPH062941U - Polarity switching circuit for load power supply - Google Patents

Abstract

(57) [Summary] (Corrected) [Purpose] When there is a DC load that requires polarity switching,
It is an object of the present invention to provide a circuit that smoothly and reliably switches the circuit. A (+) end side of the first DC power supply and a (-) end side of the second DC power supply are commonly connected to form an ground terminal, and the (-) end of the first DC power supply is connected. Side is connected in series with a first semiconductor switch, and a second DC switch is connected in series with a second semiconductor switch on the (+) end side, and a common connection point of the first and second semiconductor switches. And a DC load is connected between the ground terminal and the ground terminal.

Description

[Detailed description of the device]

[0001]

[Explanation of the field to which the device belongs]

 The present invention relates to a polarity switching circuit for supplying two types of voltages having different polarities to a DC load.

[0002]

[Prior art and its problems]

 Conventionally, this type of circuit has been constructed as shown in FIG. In FIG. 2, V1 and V2 are DC voltage sources, 1 is a control circuit for switching the polarity, and rl1 is a relay contact for switching the polarity of the main circuit. When rl1 is on the B side in the figure (2) A negative voltage is supplied to the load through a path of V1 (+)-E-load-H-rl1 (C) -rl1 (B) -V1 (-). Similarly, when rl1 is on the A side in the figure, a positive voltage is supplied to the load through the route of V2 (+)-rl1 (A) -rl1 (C) -H-load-E-V2 (-).

Such a conventional circuit has a low reliability of current capacity because the switching circuit is a relay contact, that is, low reliability of contact welding, minute current, and the like, and also has low reliability in terms of life due to mechanical contacts. There are drawbacks.

[0004]

[The purpose of the device]

 The present invention provides a circuit that smoothly and reliably switches a polarity when there is a load that requires polarity switching.

[0005]

[Means of the Invention for Solving the Problems]

 According to the present invention, the (+) end side of the first DC power supply and the (-) end side of the second DC power supply are commonly connected to form an ground terminal, and the (-) end of the first DC power supply is connected. Side is connected in series with the first semiconductor switch, and the (+) end side of the second DC power source is connected in series with the second semiconductor switch, and the common connection point of the first and second semiconductor switches is connected. , And a DC load is connected between the ground terminal and the ground terminal to electronically switch the switching circuit.

[0006]

【Example】

 FIG. 1 is a circuit diagram of an embodiment of the present invention, in which V1 and V2 are DC voltage sources, SW1 and 1 are contacts and a control circuit for driving a changeover switch, and Q1 is a first semiconductor switch ( NPN transistor), Q2 is a second semiconductor switch (PNP transistor), and in order to operate this, the transistor Q1 is driven by 1 when SW1 is on the B side. Therefore, a negative voltage is supplied to the load RL by the path of V1 (+)-E- load RL-H-Q1-V1 (-). Similarly, when SW1 (3) is on the A side, the transistor Q2 is driven and a positive voltage is supplied through the path of V2 (+)-Q2-H-load RL-E-V2 (-). Since the main circuit current does not flow through the contact SW and the control circuit 1, it may be a mechanical contact or can be easily computerized.

[0007]

[Effect of device]

 In the present invention, since the changeover switch is replaced with a semiconductor switch from a semiconductor switch, the size of the switch does not change depending on the maximum current value, and it is particularly effective for downsizing when the current value is large.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an embodiment of the present invention.

FIG. 2 Conventional circuit diagram

[Explanation of symbols]

 V1 1st DC power supply V2 2nd DC power supply SW contact 1 Control circuit Q1 1st semiconductor switch Q2 2nd semiconductor switch RL DC load

Claims (4)

[Scope of utility model registration request] 1. The (+) end side of the first DC power supply and the (-) end side of the second DC power supply are commonly connected to form an ground terminal, and the (-) end of the first DC power supply is connected. ) The first semiconductor switch is connected in series to the end side, and the second semiconductor switch is connected in series to the (+) end side of the second DC power source, and the first
And a common connection point of the second semiconductor switch and the
A polarity switching circuit for load power supply, characterized in that a DC load is connected to the terminal. 2. The load switching polarity switching circuit according to claim 1, further comprising a common control circuit for the first semiconductor switch and the second semiconductor switch. 3. N as the first and second semiconductor switches
The load switching polarity switching circuit according to claim 1, wherein a PN transistor and a PNP transistor are used. 4. N as the first and second semiconductor switches
A load switching polarity switching circuit according to claim 1, characterized in that a channel MOSFET and a P-channel MOSFET are used.