Simple EVSE Wallbox - Relais switching

Hi,
i have a question regarding the EVSE DIY wallbox. I setup everything, even with ESP8266, works fine in dry-run....means the LED changes blinking as soon as i start charging via button or in GUI.....what i was wondering, why the RELAIS does not switch in these moments.......my only guess is that the Wallbox-HW waits for a real car connected on the other end.....

Can that be the case (that relais really switches on/off only if the car is connected?)

Thanks Norbert

Yes. Due to electrical safety - there should be no Voltage on the disconnected charging Plug.

Cool. thanks....now it all makes sense

Last question, does anybody know how the SimpleEVSE realizes that the car is connected.

PP is terminated with a resistor inside of the PLUG itself, so this line does not reach the Wallbox Controller.
L & N are outputs....the same i guess is valid for CP with the PWM signal....so these lines are not intended to get input from?

Cheers
Norbert

CP is bidirectional. The car communicates to the EVSE by adding resistors and a diode between CP and PE to pull down and cut off the PWM voltage.

Thanks!!...