We found this circuit in a 1967 documentation. The integrated circuit and an operational one of the time. Modern equivalents can be tried out. The power supply is symmetrical.
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...