Found in the December 1974 issue of Radio Electronics, this circuit is similar to the previous one, only using another TTL counter. The circuit must be powered by 5 V.
This General Electric circuit was published in 1970. The LED is infrared and the voltage according...
This circuit was found in the October 1989 issue of Radio Electronics magazine. It drives an...
The transistor can be a modern equivalent and the transformer is the type of output found on an...