This circuit uses a heated filament as a sensor. With the air current it changes resistance, and the circuit detects it. The circuit is from a 1969 EEE.
Found in a 1967 Delco documentation, this circuit can deliver power from 40 to 50 W at 8-ohm load....
This circuit is from a factory documentation (National Semiconductor) of the 80's. The power...
This 1968 Mallory circuit uses an uncommon integrated circuit today. The circuit has a 30 to...