This circuit makes use of a low impedance microphone. The relay is according to the supply voltage which can be between 9 and 15 V. The operational gain is approximately 100.
This speed control for small DC motors can operate from 6 to 12 V sources. The motors can drain...
This circuit was suggested by Signetics in 1980s documentation. The circuit makes use of the...
This buffer and driver is from the integrated circuit manual itself, the Linear Technology LT1206. The...