This sewing machine motor control was found in the December 1997 Electronics Now magazine. The half-wave circuit uses a 106-type SCR.
This circuit can generate 10 MHz signals depending on the crystal and has excellent stability....
This TTL digital circuit from Texas Instruments documentation from the 1970s used the company's SN types...
We found this simple transistor tester in a French publication in 1981. It uses a common analog...