This circuit is from an 80's technical newsletter. The circuit can use any general purpose transistor and its power supply can be changed with a resistive divider to use a single 9V battery.
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...