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Wheelchair motor break question

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Ancosic:
old question... but I didn't really understand the answer...


I've purchased a pair of wheelchair motors (Jazzy Pride 1121) and I understand there needs to be 24V to lift the brakes. It has been previously suggested to just remove them- but wouldn't that be risky? having a motor without some sort of failsafe? (is it there for any other reason? it's not used in normal function right?)

if I remove them, should I install some other stopping mechanism? is it risky? I don't expect much momentum, it's pretty much just going to be a mobile platform... or moving table...

if I leave them in place, how should I supply the power? I have two deep cycle batteries to run the motor, but I can't just put this in parallel right?

briselec:
They have an electric brake for the same reason a car has brakes.
Just power them thru a suitable size relay.

Ancosic:
I was under the impression that the wheelchair motor brakes (the ones built into the motor) were only on/off and not part of normal function. So if I take them out it wouldn't effect the normal operation, but the in-case scenario of losing power....?


and I don't mean to be repetitive, but I'm not well versed in electronics... you suggested a power relay to control the brake circuit: can I run it parallel to my motor circuit (the hookup between my batteries and motors), would I risk putting too much current through this? does the power relay limit the draw?

I saw some tutorials in power regulation- but both the motor and the brakes are 24V. I don't think the brakes run off as much amperage, I 'm afraid if I hook them up together I'll fry the brakes.... should I be concerned about limiting amperage into the brake circuit?

jwatte:
When you say "can I just parallel it" it's unclear what "it" means.

Typically, you will have some kind of speed control for the motors. You don't want speed control for the brakes. (Note: "brake" not "break!")

A typical wiring diagram would be:

Two batteries in series -> on-switch and fuse -> brake circuit -> back to batteries
Two batteries in series -> on-switch and fuse -> motor controller -> motor circuit -> motor controller -> back to batteries
Two batteries in series -> on-switch and fuse -> voltage regulator -> control logic -> back to batteries

So, in this sense, the three pieces (brakes, motor, and contol) are "in parallel." For high-current systems, "on-switch" is either a relay with a small signal switch for the coil, or something like a few parallel high-performance MOSFET transistors and a small signal switch for the gates.

Ancosic:
thank you =P

would this be ok? this' what I had meant by parallel... there'd be a supplied 24 V to the brakes- are there any electrical risks associated with this?

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