We found this small audio amplifier in the November 1999 issue of Electronics Now magazine. The integrated circuit used is not very common today.
Texas Instruments' low power operational amplifiers OPAx196 can be found on Mouser Electronics....
This circuit operates with input voltages from 50 to 140 V providing an output of 12 V under...
This circuit mimics the sound of a siren when we turn the axis of the small DC motor. The...