Abstract:Aimed at the problems of uncontinuous power supply to the loads and large volume, high cost of transformer in the lighting control circuit, this paper designs an OLTC control circuit used in road lighting specially. In this OLTC control circuit, the power supply to the loads is not from transformer but grid directly, while the transformer in the circuit only provides adjusted voltage. By changing the circuit’s series or parallel structure and the transformer’s primary coils quantity through the switches in the circuit, the value and precision of voltage can be adjusted. The actual running results show that the OLTC control circuit can not only ensure continuous power supply to the load but also decrease the transformer’s volume and cost. It realizes the goal of energy saving effectively.