This test circuit was found in the PE Hobbyst Handbook in a 1990s edition. The circuit tests the battery under load. The load, as the battery is selected by the switch.
This powerful alarm circuit was found in the July 1975 issue of Radio Electronics magazine. The...
In many applications involving control of circuits from the power grid, the zero-pass detector is a key...
In this circuit the LED remains on after pressing S, for a time that depends on the capacitor...