Found in an 1989 R-E Experimenters Handbook, this circuit produces several sound effects that can be modified. The signal must be applied to an external amplifier.
The circuit presented emulates an OR gate with the LM3900, operational transconductance amplifier....
In the year of this project (1997) Walkman were common, but this unit can be used in the car with...
This high voltage source for gas LASER was found in documentation from the 1990s. The circuit is...