This flasher circuit consists of an astable multivibrator with the frequencies given by the capacitors. The circuit is from 1965 using light bulbs, but LEDs can be used. Power comes from 4 batteries.
This signal follower, from a publication from the 1970s, uses old germanium transistors such as...
This sophisticated photometer that has a light comparator with LED indicator came out in an...
The presented circuit is used to test ordinary fluorescent lamps. This circuit also has a mains...