RESUMEN
Objective To improve the voltage regulator for the traditional X-ray machine to provide heating voltage and current to X-ray tube filament heating circuit.Methods The circuits included the ones for regulator output voltage sampling,desired voltage generation,control voltage generation,synchronous pulse triangular signal generation,phase control,siliconcontrolled rectifier (SCR) and regulator input voltage sampling.Negative feedback control was executed by the sampling,detection and comparison of the regulator output voltage,and the comparison was carried out with the synchronous pulse triangular signal to generate the signal for controlling SCR.The regulator output voltage was kept stable by regulating the modes of SCR conduction angle.Results Installing and debugging of designed circuit for domestic power frequency X-ray machine contributed to realizing voltage regulation for the filament heating circuit.The test also measured voltage waveform distortion in AC circuits,and this kind of adverse effect did not affect the filament heating circuit.Conclusion The improved system has small volume,low heat,little noise and high performance,which can replace the traditional MSVR.