So when the negative part gets cut off it would be at 0V.

That's true if you don't filter the rectified wave, but when it's filtered, the output is a DC level that stays above zero (as long as there's an AC signal).

 

Thanks. Yeah, what I wrote in the previous post wasn‘t correct. I googled half wave rectifier with capacitor filter and can now see why it would stay above 0V. Thanks very much for your help, I will give this a try.