Noises before starting a TGV series Atlantique/Réseau/Duplex

[BB24000]

 

 

Good evening, I'm Guido from Germany, a trained train driver myself who had to quit due to a trauma. I'm writing here in English because unfortunately my French isn't very good, even though I visit France often.

 

I hope you'll forgive me!

 

When starting up the TGV series built between 1987 and 2006, I noticed that as soon as the main switch is turned on, or before the power car starts moving, it makes a noise that sounds like a melody, a musical scale.

 

Where does the noise come from? I know it from our ICE 1/2 and some Siemens locomotives. But they play this tune during the journey, but the TGV plays it before they set off!

 

Is it the electronics, it would have to be GTO, or is it the fans that start in rows or in stages?

 

Thank you very much for your answers.

 

With regards

 

Guido