Found in Popular Electronics from the 90s, this circuit consists of a timer that turns off the power of a circuit after a time determined by C1, saving the battery.
In the figure we have the circuit of a multi-range ammeter using a 50 uA full-scale instrument. The...
We found this circuit in a Radio Electronics magazine from December 1969. The circuit uses a...
This blocking oscillator was found in a publication from the 50's. The coils determine the...