We found this circuit in a 1968 Electronics World. The transistors are from the era and information about the transformer was included. Transistors support current equivalents.
Using bipolar, FETs and unijunction this long-lasting timer can reach 10 hours with good quality...
The configuration shown is from the National Semiconductor Linear Applications Handbook. The...
This shield circuit uses a common CMOS port. The voltage depends on the interfaced logic. The...