We found this small audio amplifier in the November 1999 issue of Electronics Now magazine. The integrated circuit used is not very common today.
The Motorola MOC501O optocoupler has a complete amplifier inside the sensor, enabling the...
This circuit is suggested by the Texas Instruments manual of linear applications of the 90's. The...
This circuit was found in the Radio Electronics magazine of May 1990. The supply voltage depends on...