We found this circuit in a 1980s American documentation. The operational amplifiers of the integrated circuit used can be common types in an experimental setup.
The simple touch of the fingers on a sensor causes this circuit to drive a motor that goes into...
This simple circuit found in an American 80's documentation simply blames if there are toxic gases in...
This circuit is from Motorola's 1990 Linear Databook. The transistors allow equivalents and the...