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.
This circuit is suitable for applications such as a TTL log digital link. Maximum frequency is...
We found this simple wired intercom circuit with transistors in a 1988 publication. In addition to not...
Other operational amplifiers can be used on this unit gain amplifier. The circuit is from the 1993...