Indicated for automotive use, this circuit was found in a Popular Electronics from the 90s. The circuit uses a power transistor that must be equipped with a heatsink.
This configuration with the LM111 was found in your factory manual. The circuit can be implemented with...
The double T of this circuit makes it amplify only the 1 kHz signals. The circuit can be used as a...
This car alarm was obtained in a Signetics documentation from the 1980s. The circuit uses the 555...