JPH0272679U - - Google Patents

Description

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing the configuration of an embodiment of the present invention, Fig. 2 is an explanatory diagram of the operation of two photocouplers in the embodiment of Fig. 1, and Fig. 3 shows the operation of the embodiment of Fig. 1. FIG. 1... Constant current converter, 2... Load, 3a,
3b...Hotocoupler, 4...EX-OR gate,
5...Second AND gate, 6...Second AND
gate, Q1 _p , Q2 _p ...exciting element, Q1 _t ,
Q2 _t ... Light receiving element, R1... First resistor, R2
...Second resistance.

Claims (1)

[Scope of Claim for Utility Model Registration] In a transformer-insulated constant current converter that receives a DC input power supply and supplies a constant current of equal positive output and negative output to a load, inserted first and second resistors; first and second photocouplers that receive a forward bias voltage from the positive output and the negative output into a light emitting element using a light emitting diode; and the first and second photocouplers. Exclusive logic that receives the outputs of both collectors in an operating state by connecting the collectors of the photodetector using phototransistors to a positive power source through respective resistors and connecting the emitters to a negative power source through a common resistor. a sum gate; a first AND gate having two inputs: the collector output of the light receiving element of the first photocoupler and the output of the exclusive OR circuit; the collector output of the light receiving element of the second photocoupler and the exclusive OR circuit; a second AND gate whose two inputs are the outputs of the logical OR circuit; A voltage unbalance detection circuit for a constant current converter, which detects unbalance in output voltage.