Low battery indicator (CB9133E)

This circuit was found in Maxim's documentation from the 80's. The integrated circuit is from that time, uncommon today.

Field Intensity Meter (CB19589E)
This circuit has a traditional configuration explored in several other points of this site. The...
SCR Flasher (CB23953E)
We found this traditional flasher configuration in a June 1969 Radio Electronics magazine. SCRs...
Instrumentation AC Amplifier (CB12124E)
This circuit was obtained in a 1979 publication. The operational amplifier is of the type with...