This electronic Morse key was found in a Popular Electronics from the 90's. The components are common, but there is a mechanical part that requires assembly skills.
This circuit was found in the SGS manual of linear integrated circuits of 1982. The CMRR depends on...
In the figure we have a receiver for frequency modulated light signals (see the transmitter in...
In the figure we have a high stability voltage reference, providing a voltage of 10 V at the...