This basic circuit was found in the March 1998 issue of Electronics Now magazine. The circuit is powered by 2V and uses a 28 MHz crystal or resonator.
This simple half-wave control using an SCR, which may be TIC106, has been obtained from a US...
I found this circuit in an English publication from 1989. This configuration can be mounted with...
This reader with TTL logic compatible output uses an LM139 comparator. The circuit was found in...