This circuit from the 90s, found in an Electronic Engineering can be used as a shield since its control is digital with TTL logic of 5 V. The components used are still common today.
The transmitter can be that of CB9574E. This receiver uses a PLL to directly trigger a sensitive relay....
This circuit can be used in alarms to generate a warning signal. The circuit is from a 1960s...
Author: Newton C. Braga Published:August 1, 1998 Formato:Book and e-Book Pages:...