The circuit presented was obtained in a technical documentation from National Instruments. The low-consumption circuit supplies a common LED with a voltage of just 1.5 V.
We adapt this circuit of Radio Electronics - March 1990. The magazine no more exists, but the...
The input impedance of this circuit is about 700 k ohm and the output impedance is about 1 k ohm....
Radio Electronics magazine published in a 90's issue this simple alarm that can use any general...