This circuit activates a relay after a time given by C1 and R1. The circuit is from a Radio Electronics from December 1974. The relay voltage is the same as that used in the power supply.
This circuit was found in a 2006 publication. It uses discrete components and CMOS that are still...
The sensor of this circuit is a common diode, and the measured range is from -10 to + 40º C. The...
The circuit presented was found in the Linear Applications Handbook of the National Semiconductor of 1994....