AC voltage probe (CB8185E)

This circuit for voltages up to about 20 V was found in a 90s Popular Electronics. The LED can be of any type or color.

Memory sensor amplifier (CB6809E)
This circuit is from a 1967 documentation. It consists of a sensor for memories used at the time....
10W Amplifier LM1875 (CB25523E)
We found this circuit in the November 1992 issue of Radio Electronics magazine. The circuit has...
Flasher with two settings (CB6802E)
Found in EEE documentation, this circuit can have the duration and frequency adjusted separately....