Patent ID: 7034607

Claim:
A switching constant-current power device comprising: a switching-system power converter, which supplies a predetermined current to a load; a current detector, which generates a first feedback signal in accordance with a load current; a controller, which drives the power converter so as to stabilize the load current in accordance with the first feedback signal; a voltage detector, which creates a voltage signal in accordance with an output voltage of the power converter; and a feedback circuit, provided between the current detector and the controller having a signal holder outputting a second feedback signal that was created after consulting the voltage signal, the signal holder creating the second feedback signal that is larger than the first feedback signal, created by consulting the voltage signal at a given time when a specified load current is flowing to the load. and maintaining the signal level of the second feedback signal for a given period of time, the feedback circuit supplying the first feedback signal to the controller when the load current is flowing, and supplying the second feedback signal to the controller when the load current is not flowing, wherein the feedback circuit supplies either the first feedback signal or the second feedback signal to the controller in accordance with a load status.