SILICON-CONTROLLED RECTIFIER-COMPATIBLE CONSTANT-VOLTAGE CIRCUIT, LED DIMMING CIRCUIT, AND RELATED LED LIGHTING APPARATUS

摘要

A silicon-controlled rectifier (SCR)-compatible constant-voltage circuit that includes an input undervoltage control module, an overpower protection module, a controllable load module, and a power conversion module is provided. The input undervoltage control module, the overpower protection module, and the controllable load module are connected in parallel between a first sampling point and the power conversion module, and the first sampling point is arranged between an SCR and the power conversion module. The power conversion module is configured to provide a constant voltage to a load module. The input undervoltage control module and the overpower protection module are configured to control the power conversion module to start or stop power conversion based on a voltage at the first sampling point. The controllable load module is configured to maintain the SCR to be on when the power conversion module stops power conversion.