The figure shows the equivalent circuit for the LM381 audio preamplifier IC. The circuit was found in the February 1990 issue of Radio Electronics magazine.
The presented circuit activates a relay when a telephone call occurs. The relay can be used to...
The accuracy of this circuit depends on adjustments made with capacitors of small tolerances of known...
This diode tester was found in an English publication from the 1980s. Transistors are...