24 VDC Motor Braking

When the motor is reversed is the field or armature current reversed?

That is correct Tony

Best Regards

Joe

Hay John, I found the manual not a lot more info but enough. Glad to help.

That is a good idea John, but I will be posting shortly just what I have done, watch this space.

Thanks Mate

Best Regards

Joe

With zeners etc you are trying to dissipate the kinetic load energy as heat.For this you will need massive components and possibly go into other problems. Not really familiar with the controller model but since it is reversible, chanses are it uses a power H-bridge at output so it's inherently capable of regenerating. Try this. Adjust maximum current pot at the minimum level it suites your load's max required acceleration, and test systems behavior. At brake command then it must also restrict braking current and possibly give you the braking time you want. (You will also possibly have to control overvoltage at braking on your power supply by adding bigger caps.) S.M.

Hi Redfred, you can put a deceleration ramp into the drive but this does not work as to how I want it to work, the problem is if you set a decelleration ramp of lets say 2 seconds that means from full speed to stop is 2 sec, it also means if you are running at half speed the time taken to stop is still 2 sec.

Redfred thanks for your input mate, I will also post a statement on what I have done shortly to overcome the problem.

Best Regards

Joe

Thanks to all contributors.

The motors that I have been using are 500 watt and the problem is that we need to operate the motors in various ways from 0- full speed CW and also from 0-full speed CCW there is 2 motors and they don't necessary do the same operations at the same time. When we set a deceleration curve time of say 2 seconds this means that whatever speed we are doing that the deceleration ramp is always 2 seconds, and this did not fit the deceleration ramp profile that I required, so for instance if the motor was operating at half speed we may require a deceleration ramp of 1.2 seconds

I decided today to use a wheel chair controller and installed this today in the prototype machine, with a few programme changes this it has so far has exceeded all expectations.

I would like to tell you all more but I cant "confidentially and all that stuff", I may post something in about 2 months, a video clip of the operation, but i can't do that now due to the customers patient pending.

But I would like to thank all contributors for the informative information that has been contributed.

I take a Bow!

Best Regards

Joe

Use a suitably made/sized resistor in the circuit.....you only need to reduce current....

Yes, but where in the circuit is the issue here.

Anyway, Joe seems to have sorted himself out by using a different drive.

If you short the motor, it stops very abruptly. Adding resistance in place of the short, will slow it down "slower"!!

Its a very common method of slowing down a motor......

"If you short the motor ..." - what, short the stator to the frame? short the field winding to ground? short the armature winding to the field winding?

No need to try to be clever, or to state the obvious (again) Andy - if you read through the thread so far, you'll see it's already been said.

(And don't (again, try to) teach your grandmother to suck eggs).

I was going to post this, but I can't be ar$ed.

Wow! Bad hair day?

You remove the supply and place a short across the supply terminals to the motor. Or you place a resistor across those terminals...

Remember - Remove supply first!!!

Its often done with a relay or a switch......like this for example:-