Dimming power supply

Abstract

The invention discloses a dimming power supply, which comprises a rectification input filtering unit, a flyback control unit, an isolation transformation unit and a dimming unit which are arranged in sequence, and is characterized in that the flyback control unit comprises a conduction time setting end which is used for setting the conduction time of a silicon controlled rectifier in a dimmer; the conduction time adjusting unit comprises a first resistor unit, a switch unit and a second resistor unit, when the switch unit is switched off, the second resistor unit is in an open circuit state, and the conduction time is determined by the resistance value of the first resistor unit; when the switch unit is switched on, the second resistor unit and the first resistor unit are connected in parallel, and the switching-on time is determined by the resistance value after the first resistor unit and the second resistor unit are connected in parallel. When the actual conduction time of the silicon controlled rectifier of the dimmer is inconsistent with the set conduction time, the conduction state of the switch unit changes, so that the conduction time of the silicon controlled rectifier in the dimmer is adjusted, and the dimming depth is deeper.

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