The load of this circuit depends on the triac and the integrated circuit used is uncommon today. The circuit is from 80s documentation. The triac must have a heat sink.
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...