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.

Power Outage Alarm (CB5952E)
We found this circuit very simple in an old documentation. The relay is high voltage sensitive, but...
Triac isolated trigger (CB8030E)
This circuit was found in a Radio Electronics from 1970. The coupler with LDR is from that time,...
Diac Phase Control (CB13368E)
This circuit is from a publication about thyristors from the 70s. It consists of a pulse generator...