Aiming at the shortage of the power supply system of the portable electromagnetic radiation detector

a power supply system with excellent performance is designed. The system adopts forward converter as the main circuit and adopts the low side of the active clamp circuit as reset circuit. The double closed-loop control mode

the current peak detection is adopted and a temperature control system is added. The soft switching operation mode of the power switch tube is realized

the electromagnetic interference is reduced

the dynamic response is improved

and the voltage output ripple is reduced. Low-temperature characteristics is improved for enhancing power endurance. The system is applied in portable electromagnetic radiation detector

the rationality of design is proved.