High power bipolar stepper driver

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asad111

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I want to drive my bip-stepper with max 48volt and 15amp, so I found the driver as shown in attached image. Please show your expert comment, if it is actually useful for my application. You can suggest any change or another driver.

My motor:
Bipolar 3-ohm wind-resistance (weight 4kg)
No more info....
 

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Hi,

I doubt the values of your stepper: 48V, 15A, 3Ohms.
If it has 3Ohms winding and you drive 15A to it, then the dissipated power is about 700W.
Even a 4kg motor needs heavy cooling (water, massive air flow) to withstand this.
Then with 15A and 3Ohms is 45V ...with the given 48V you don't have much headroom to speed up.

I also doubt the values in the circuit.
If it really should be suited to drive 15A then the current sensing resistors of 0.2Ohms generate a voltage drop of 3V (reducing gate drive voltage) and causing a huge of 45W of heat each. What size is it? A shoe box?

I think there must be something wrong.

Klaus
 

Thanks for expert reply.

Unfortunately, there is not any label on motor. I just measured the resistance.

I only want to run it at 40-48volt to achieve max speed.

Last time, i tested this motor with L297,98 driver at 12volt. Using mach3, the max speed was 80mm/minute (133 full steps per mm). But after some time, L297 blew (stop working), so I decided to turn to other driver.

You can suggest changes in above attached schematic or suggest another one.
 

Hi,

without datasheet and without any specifications ... all you can do is "assume" and "try".

You say you want to run it at 40-48V level. But a stepper motor usually is current driven, to limit dissipated power by optimal torque and optimal speed.
How much current...Nobody can tell.

Klaus
 

I don't know in depth and just read on forums, that speed is based on voltage and torque is based on current.

Let say, I run this stepper on 12volt, then do I only need to increase or decrease the current to control the torque and speed?

If it is, then I think I should use L298,97 driver with a separate current control circuit. It is only my guess, not based on knowledge or experience.

Now which method would you like to recommend for this stepper? You can also recommend circuit (s).
 

As I have shown in my above post, that at 12V I just could be able to get speed of 80mm/minute (133 full steps per mm). When I tried to increase the frequency, then motor started missing the steps (I think due to low torque ~ low current).

I think motor can start working at higher frequency if I increase the current as described in this thread

So I should use 'Current Drive'.

Can I use 'Current Drive' with L298 L297 to provide more than 2A (limit of L298).
Should I use other driver circuit to use ''Current Drive''.
Please guide me regarding ''Current Drive''
 

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