Suggested by Siliconix in documentation from the 90s, this amplifier has its gain digitally selected. The components are from that time, not easy to find today.
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...