Abstract: A programmable system includes a first level protection circuit comprised of discharge tube CR1/ CR2 and piezoresistor MOV1/MOV2 in series; a second-level protection circuit comprised of the series arm of capacitor C1 and resistor R1 in parallel with a transient voltage suppression diode TVS1, and inductors L1/L2 connected to the ends of first level and second-level protection circuits respectively. A control circuit includes a PWM driver module and a SCM. The PWM driver module is connected to the PWM control port of the SCM and its output is connected to an IGBT module. The control circuit is also connected to a series communication module and to a user interface. The features of the invention are: strong-shock resistance; a wide range of load adaptability; and ability of accurately and steplessly regulating and adjusting with high frequency and high power load.