SECONDARY ELECTRIC POWER SUPPLY UNIT Russian patent published in 2010 - IPC H02M3/335 

FIELD: electricity.

SUBSTANCE: device includes input "plus" and "minus" terminals intended to be connected to buses of primary electric power source, output "plus" and "minus" terminals intended to be connected to load, as well as transformer with primary and secondary windings. Outputs of secondary winding are connected through rectifier and smoothing filter to output terminals. The first output of primary winding is connected to "plus" output of the first capacitor, as well as through electronic current limiter to input "plus" terminal. The second output of primary winding is connected to the first power output of electronic key, the second power output of which is connected to "minus" output of the first capacitor and to the first output of resistive current sensor the second output of which is connected to input "minus" terminal. Control output of electronic key is connected to output of control circuit the power outputs of which are connected to input terminals, and outputs of feedback are connected to the first output of resistive current sensor and to the feedback circuit output as to voltage. Electronic current limiter includes electronic control element, feedback transistor, stabilitron, the first, the second and the third diodes, the second and the third capacitors, as well as the first, the second, the third, the fourth, the fifth, the sixth and the seventh resistors. Control output of electronic control element is connected to the second output of primary winding through in-series connected the first resistor and the first diode, as well as through the second capacitor to the first output of resistive current sensor. The first power output of electronic control element is connected to input "plus" terminal, as well as through the second resistor and the second diode in-series connected to their control output. The second power output of electronic control element is connected to the first output of primary winding, as well as through the third resistor and the third capacitor, which are parallel connected, to their control output to which feedback transistor collector is connected. Feedback transistor emitter is connected through the fourth resistor to input "plus" terminal, and through the third diode - to input "minus" terminal, to which there also connected in series is the fifth resistor and stabilitron. Base of feedback transistor is connected through the sixth resistor to stabilitron cathode, and through the seventh resistor - to the first output of resistive current sensor.

EFFECT: decreasing input start-up current.

2 cl, 5 dwg