Disclosed are a constant-power supply apparatus and a solar simulation facility. The constant-power supply apparatus comprises: a power board and a control panel, wherein the power board comprises: a power input circuit for providing a power input, a power conversion circuit connected to the power input circuit, a voltage detection circuit, a current detection circuit and a power output circuit respectively connected to the power conversion circuit, and a first connector connected to the power conversion circuit, the voltage detection circuit and the current detection circuit; and the control board comprises: a second connector pluggably connected to the first connector, a voltage processing circuit and a current processing circuit respectively connected to the second connector, a multiplier circuit connected to the voltage processing circuit and the current processing circuit, and a PWM circuit connected to the current processing circuit, the multiplier circuit and the second connector. A stable power output can be provided, and reliability of circuits is guaranteed.

A dimmer control circuit for controlling a phase cut dimmer includes: a rectifier circuitry, configured to rectify the output voltage of the phase cut dimmer to output a rectified voltage; an input voltage detecting circuitry, configured to output a detected voltage according to the rectified voltage; a processor, configured to output a control signal when the detected voltage meets a preset condition; and a constant current circuitry, configured to output or stop outputting a preset current to the rectifier circuitry in response to the control signal; wherein the preset current has a value greater than a holding current of the phase cut dimmer.

A dimmer control circuit for controlling a phase cut dimmer includes: a rectifier circuitry, configured to rectify the output voltage of the phase cut dimmer to output a rectified voltage; an input voltage detecting circuitry, configured to output a detected voltage according to the rectified voltage; a processor, configured to output a control signal when the detected voltage meets a preset condition; and a constant current circuitry, configured to output or stop outputting a preset current to the rectifier circuitry in response to the control signal; wherein the preset current has a value greater than a holding current of the phase cut dimmer.