[major]

Hello everyone, I am repairing a curtis 1244, I see that it has an H bridge to feed the motor rotor.
If the positive of the battery goes directly to the motor, why does it require a bridge h? Greetings and thanks.

The Curtis 1244 SepEx uses a full (H) bridge for the field (stator) and a half bridge for the armature (rotor).

major

 

[major]

Perfect, but why half a bridge in the rotor? To brake? I am changing mosfet and wanted to save me some of the half bridge high side, will it work? Thank you.

You need at least two switches. What I call a quarter bridge consist of a gated switch like a mosfet for the chopper and a diode for freewheeling giving single quadrant operation. A half bridge uses two gated switches (mosfets) with synchronous rectification and gets regenerative capability for two quadrant operation. The full H bridge is needed for 4 quadrant operation.

major