Multi-mode dimming and color temperature adjustment power supply based on PWM

A multi-mode dimming and color temperature adjustment power supply based on Pulse Width Modulation (PWM), comprising a power supply conversion circuit, wherein the power supply conversion circuit is configured to convert an input power supply voltage into a working power supply voltage for a load, and further comprising:

• an Electromagnetic Interference (EMI) and rectification filtering circuit, a phase-cut signal input circuit, a signal processing circuit, a main control circuit and a dimming circuit, wherein the EMI and rectification filtering circuit receives a power supply and is configured to filter out high-frequency interference signals in the AC power supply and rectify the power supply into a pulsating DC voltage and output to the phase-cut signal input circuit;
• the phase-cut signal input circuit is configured to convert the pulsating DC voltage signal into a first PWM signal and output to the signal processing circuit;
• the signal processing circuit is configured to convert the first PWM signal into a DC voltage signal and output to a first input terminal of the main control circuit and output a second PWM signal to a second input terminal of the main control circuit after filtering;
• the main control circuit is configured to determine whether a current input signal is a phase-cut dimming signal or a phase-cut carrier color temperature adjustment signal based on a state of the second PWM signal, and if the current input signal is the phase-cut dimming signal, outputs a corresponding first PWM dimming signal to the dimming circuit according to a magnitude of the DC voltage signal to achieve dimming of the load;
• and if the current input signal is the phase-cut carrier color temperature adjustment signal, performs signal processing and outputs a corresponding second PWM dimming signal to the dimming circuit according to a color temperature data signal to achieve color temperature adjustment of the load;
• wherein, a third input terminal and a fourth input terminal of the main control circuit respectively receive a first analog signal and a second analog signal, and the main control circuit is configured to output the corresponding first PWM dimming signal to the dimming circuit according to a magnitude of the first analog signal to achieve dimming of the load;
• or adjust a value of the second PWM dimming signal according to a magnitude of the second analog signal to achieve color temperature adjustment of the load.