Found in a Popular Electronics from the 90s, this circuit uses components that are still current. The circuit triggers the vehicle's horn. The sensors can be increased in number.
The circuit shown in the figure was found in a 1974 publication. The field effect transistor may...
I found this circuit in an English publication from 1989. This configuration can be mounted with...
We found this circuit in a small espionage manual from 1993. The components are current, and the...