This circuit for light modulated in frequency (FM) was found in documentation of the 90s. SUS is uncommon today, but transistors admit equivalents.
This is one of the first radios with an integrated circuit. The circuit is from a Radio...
This circuit already incorporates the amplification stage, since the oscillator is of the type of...
Output stages driving relays or other loads are plugged to the outputs of a 4017. The trigger...