FIELD: electricity.
SUBSTANCE: power supply circuit is provided, which may be used everywhere without application of switching element with high withstanding voltage, and which may produce stable power for loading device. Charging unit (14) is installed between locking capacitor (C4) and loading coil (L2). Charging unit (14) comprises anode connected to positive lead of feedback coil (L3) and cathode connected to cathode of stabilitron (Z1). Therefore, at high voltage in power supply network (E) of common use, charging unit (14) operates, at the same time locking capacitor (C4) discharges quickly, period of open condition of transistor (Q1) reduces. At the same time flat output characteristic is provided, which indicates ratio between voltage in power supply network (E) of common use and current passing in loading device.
EFFECT: invention prevents supplying excessive voltage between transistor drain and source.
10 cl, 17 dwg
