Can I connect the transmitter to a 12V power supply in my car instead of using the battery? The power source comes from a 5W lamp socket (12V, 5W, 400mA) in the car interior. If this is possible, can I place the PCB in the car with the transmission button continuously pressed in and generate the transmission code to the K8057 receiver by switching the power source from the lamp on/off?

Theoretically, this is possible, but not guaranteed to work. This is an RF device and it has been developed for use with internal battery i.e. no external wiring which could act as an antenna and worsen the range. Please experiment.

You could be right about possible interference, so I will experiment. How about the 2nd part of my question…can I generate the code by switching the 12V power supply from OFF to ON (if transmission button remains pressed in the application)?

That should work fine.

The application has been fitted and works perfectly! Thanks for the support.