We found this circuit in a Popular Electronics of the 90s. The circuit can be easily mounted today, as the components are common. The SCR can be the TIC106.
This 90's Electronic Design circuit converts the period of a signal into a frequency. The...
This Radio Electronics circuit, in an 80's edition, decodes the 67 kHz signal used at the time to...
This logic circuit can indicate both TTL (5 V) and CMOS (5 to 12 V) output levels, operating with...