This alarm goes off if someone leaves a door open. We found it in the Encyclopedia of Electronic Circuits Volume 5 from 1995. The circuit uses components that are still common today.
The figure shows how to divide the frequency of a signal by 17 using the 4017. Additional CMOS...
This circuit was obtained from a Popular Electronics. The component is a UJT. The circuit has an...
This 1990 circuit is based on an uncommon integrated system that gathers all the resources for the...