Rotating transformer exciting circuit based on sinusoidal pulse width modulation (SPWM)

The invention discloses a rotating transformer exciting circuit based on sinusoidal pulse width modulation (SPWM), which comprises a microprocessor, an analog demodulation circuit and a power amplification circuit, wherein the microprocessor adopts DSP to perform digital modulation so as to load a required sinusoidal fundamental wave signal to a high-frequency square wave carrier signal to form an SPWM wave signal, and output SPWM waves to the analog demodulation circuit in a differential mode. The analog demodulation circuit adopts a two-circuit duplicate-supply operational amplifier TL082, and one path of the operational amplifier forms a differential proportion calculator, while the other path forms a filter. The power amplification circuit adopts a two-circuit duplicate-supply linear power amplifier PA60 and a resistor to form a two-circuit reversed phase proportioner, and blocks the input sinusoidal fundamental wave signal and amplifies the power to generate an exciting signal and simultaneously drive a two-circuit rotating transformer to work. The rotating transformer exciting circuit has the advantages of simple circuit, safety and reliability, small temperature drift and direct current component, good stability of output signals, and low degree of distortion of output waveforms.