This circuit is from an 80's publication. It makes use of small 6 V x 50 mA incandescent lamps. The diodes can be general purpose or even 1N4002. The transformer is 6.3 V with 100 mA or more current.
This circuit needs only 0.7 V at 40 uA to drive the relay. We found it in the November 1993...
This reflex receiver was obtained from a 1963 documentation. The transistors are germanium, and...
Obtained from an Electronic Engineering of the 90s, these circuits can be applied to almost any...