This circuit also appears elsewhere on this site, obtained from other sources. This is an 80's American schematic book. Instead the lamp can be used white high-brightness LEDs.
This excellent circuit came out in a Japanese publication from 1971. It uses Japanese transistors of the...
This circuit is from the owner's manual of the integrated circuits used. The manual is old, which...
We found this circuit in an English documentation from 1995. The Hall sensor used is from the time...