Hello,

I sketched the following circuit from a DC motor control board. The board has a note on the silk layer: For 120V, connect J1 and AC2.
This might be a simple question, but I got a bit confused. What is electrically achieved by making such connection?

 

It's designed to be a Voltage Doubler, so that it runs on 230V normally.

 

It's designed to be a Voltage Doubler, so that it runs on 230V normally.

Thank you. I had never worked with voltage doublers before. I'll look into that.