Question bridge H in controller Curtis 1244

marcelo2112 said:

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.

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To reverse the field coils for changing motor direction, I'd say.

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marcelo2112 said:

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.

Click to expand...

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

major

major said:

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

major

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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.

marcelo2112 said:

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.

Click to expand...

Here's the Curtis Manual for the 1244:


http://www.fsip.biz/Documents/ACFWC9e9x.pdf


And it's an Armature, not a rotor. DC shunt wound motor.

marcelo2112 said:

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.

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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

Thank you. Then I have to change all the mosfet.

I ask the experts, what is the circuit that closes the main contactor? I have the code 3.4, change all the lm339 but I do not understand the circuit that activates the mosfet, where does the signal that activates it come from?