NE602 Crystal Oscillator (CB26005E)

This oscillator reaches 50 MHz with an overtone crystal. The circuit is from Electronics Now magazine from February 1997.

Electronic Roulette (CB6362E)
This circuit that draws 1 out of 8 LEDs was found in an 80's American documentation. The circuit...
Current relay (CB22522E)
This protective circuit for power lines was found in a Radio Electronics from November 1957. The...
Precision current drains (CB15421E)
In figures 1 and 2 we have two current drains that can be made with operational amplifiers and...