This circuit turns on an indicator lamp (or an LED with a resistor) when the power is cut and keeps the indicator on, even after the power returns. The circuit is from an old documentation and the transistors, like the SCR, admit equivalents.
This circuit turns on an indicator lamp (or an LED with a resistor) when the power is cut and keeps the indicator on, even after the power returns. The circuit is from an old documentation and the transistors, like the SCR, admit equivalents.