English: This oscillogram shows a bench power supply current limit circuit operate on the inrush surge of a small incandescent lamp. Lamp current is in yellow, approximately 2 amps/vertical division, power supply voltage is pink, 5 volts/division. For a fraction of a millisecond, the lamp attempts to draw about six times its steady-state current. The overcurrent protection circuit of the power supply dropped the output voltage from 13.9 V down to about 3 volts to limit current and protect the power supply. After about 100 milliseconds, the foldback current limit circuit resets and the voltage returns to full value - a small extra surge of lamp current occurs when the voltage is restored, then the lamp slowly returns to its steady state current draw of 2.3 amps.