This circuit is from a 1967 Triplett manual. The circuit uses components of the time, the common FET and the general-purpose bipolar transistor.
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...