This circuit is from the 1990 Motorola Linear Databook, which can be developed with more modern equivalent operating systems. The 1 uF capacitor should be of good quality polyester with small leaks
This circuit was found in a Radio Electronics from October 1952. The circuit equalizes the sounds...
This low frequency square wave oscillator using the 741 Operational Amplifier produces sound when...
We found this circuit in an old documentation. The instrument can be an ordinary multimeter in the...