Isolated power supply feedback

摘要

The switching power supply has pulse width modulation controller 51 isolated by transformer 35, which is connected by line 33 to the output, VO, across lines 27 and 29. An alternating input is obtained from transistor 19 acting as a switch controlled by alternating signals on line 15 connected to node C. Diode 37 in series with resistor 39 provides damping. Response is very fast and effective, and the input elements, including controller 51, are fully isolated.