Patent ID: 7106037

Claim:
A switching-type constant current power supply device including a switching-type power conversion circuit for supplying a given current to a load connected to the output side thereof, a current detection circuit connected to said load and adapted to generate a first feedback signal proportional to a load current, and a control circuit connected to said power conversion circuit and said current detection circuit and adapted, in response to receiving said first feedback signal, to stabilize said load current, said switching-type constant current power supply device comprising: a voltage detection circuit connected to the output side of said power conversion circuit, and adapted to generate a second feedback signal proportional to an output voltage of said power conversion circuit; a feedback circuit connected to said current detection circuit, said voltage detection circuit and said control circuit, and adapted to supply either one of said first and second feedback signals to said control circuit; and an alteration circuit connected to a given position of a circuit block comprising said voltage detection circuit, said control circuit and said feedback circuit which are connected with each other, and adapted, in response to a change in said load, to alter a relative magnitude relationship between a reference voltage and said second feedback signal which are to be entered into a common error amplifier in said control circuit.