Patent ID: 7403406
Filing Date: 2008-07-22
Classification: H02M

Abstract:
1. An electronic current limiter, comprising: a power supply transformation circuit to transform an alternating-current power supply into a direct-current power supply, wherein the power supply transformation circuit includes two input terminals and a direct-current output terminal; a current detection circuit to sense and detect a current from the input terminals of the power supply transformation circuit, wherein the current detection circuit includes a current transformer which consists of a primary coil and a secondary coil, the primary coil of the current transformer of the current detection circuit is electrically connected between two lamp connecting terminals of the current detection circuit and the input terminals of the power supply transformation circuit, and the secondary coil of the current transformer of the current detection circuit is connected to a rectifying diode of the current detection circuit to form a voltage signal output terminal of the current detection circuit; a detection control circuit to turn on or off the power supply according to an output signal of the current detection circuit, wherein the detection control circuit includes a silicon control rectifier, a relay and a reset switch, the relay of the detection control circuit is electrically connected between the direct-current output terminal of the power supply transformation circuit and a positive pole of the silicon control rectifier of the detection control circuit, the silicon control rectifier of the detection control circuit has a negative pole and a control gate electrically connected with the voltage signal output terminal of the current detection circuit, the reset switch of the detection control circuit is electrically connected with the voltage signal output terminal of the current detection circuit, the relay of the detection control circuit has a switch electrically connected between the primary coil of the current transformer of the current detection circuit and the lamp connecting terminals of the current detection circuit, the switch of the relay of the detection control circuit has a normally closed contact electrically connected with one of the lamp connecting terminals of the current detection circuit.