Patent ID: 9535443
Date: 2017-01-03
CPC Classifications: G05F,H02M,H02P,H05B

Claim:
1. A middle phase power-fetching type phase front/phase tail synchronized modulation circuit, comprising: a power supply unit, and a phase front/phase tail modulation unit, including an MCU microcomputer, a light coupling switch, a driving circuit, and two bi-directional electronic power supply elements, wherein, said power supply unit is used to fetch power from a middle phase of an ordinary AC voltage waveform, and supplies it to said phase front/phase tail modulation unit as a normal working voltage after rectification, and wherein said MCU microcomputer controls said driving circuit separated by said light coupling switch to turn-on, to control synchronously at least two Power MOSFETs of bi-directional electronic power supply elements, so as to generate a phase front/phase tail turn-on modulation signal; wherein said power supply unit supplies power to said driving circuit through a constant current circuit; wherein said power supply unit further includes an AC zero voltage activation and sampling circuit, to activate said electronic power element at zero voltage.