With this circuit you can produce the sound effect passing from one channel to another. The circuit is from Mullard documentation from the 1960s. The transistors may be the BC548.
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:...