This circuit, to add the ambience effect, was suggested by National Semiconductor in documentation from the 90s. The amplifier needs an appropriate power source.
The circuit in the figure uses two operational amplifiers: an LM101A and an LM102. Diodes admit...
This simple circuit can use any general-purpose transistor. The power supply must be isolated. The circuit...
Up to 0.5 A DC motors can be controlled by this circuit. Direction change is achieved by a logic...