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.

Complete Alarm System (CB24383E)
This circuit was found in an article in Radio Electronics magazine from May 1975. The circuit has...
Sequential Flasher (CB25044E)
We found this circuit in the February 1987 issue of Radio Electronics magazine. It is based on an...
Photo Timed Voice Relay (CB16823E)
This interesting circuit, which can be used as an alarm, was found in a 1997 documentation. It...