Found in a 90s Popular Electronics, this mixer can be expanded to more channels. Transistors can be modern general-purpose equivalents.
This circuit that equipped many transistor radios from the 50's was found in an American...
Mouser Electronics is supplying the SMi (Silicon Microestructures) uncompensated low pressure...
This circuit applies to small gearboxes with motors that do not exceed 200 mA. The circuit is from...