28V overvoltage surge suppression circuit

The invention belongs to the technical field of power supplies, and relates to a 28V overvoltage surge suppression circuit. Comprising a field effect transistor, a voltage stabilizing tube, a linear optocoupler, a precise voltage stabilizing source, a filter capacitor, a divider resistor, an integrating capacitor and a current limiting resistor. The 28V overvoltage surge suppression circuit can adjust voltages at two ends of a grid electrode and a drain electrode of a field effect transistor by utilizing different conduction impedances when the field effect transistor is not completely conducted when an overvoltage surge occurs at a 28V input end, so that the purpose of adjusting the voltages at two ends of a source electrode and a drain electrode of the field effect transistor is achieved, and the stability of an output voltage is further ensured; the circuit is reasonable in design, small in size and few in used components, the used components are conventional components such as conventional field effect tr