Author Topic: Driving LED with PWM speed controller or step motor driver?  (Read 1771 times)

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Offline zappedy

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Driving LED with PWM speed controller or step motor driver?
« on: November 04, 2015, 08:58:55 am »
Can I do that? I have 3x 3W LED stacks that take 700mA each, but no means to drive it. I have one of these however (or approx. the same)

But I was also going to get a step motor controller, can I use that instead, like an EasyDriver?

So, I put a small inductance in series?

I realize a DC-DC power module would be the right thing, I'm just curious if motor drivers would work.

Just asking before trying so I don't burn anything.
« Last Edit: November 04, 2015, 09:17:31 am by zappedy »
 

Offline tron9000

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Re: Driving LED with PWM speed controller or step motor driver?
« Reply #1 on: November 04, 2015, 09:04:30 am »
having trouble viewing those links
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Offline zappedy

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Re: Driving LED with PWM speed controller or step motor driver?
« Reply #2 on: November 04, 2015, 09:17:43 am »
fixed
 

Offline tron9000

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Re: Driving LED with PWM speed controller or step motor driver?
« Reply #3 on: November 04, 2015, 09:30:51 am »
Stepper drivers and simple PWM drivers work differently.

Stepper drivers typically have a H-bridge to drive the motor coils. This allows current to flow in either direction through its coil.


The PWM driver looks like some sort  of astable chip, whose output is adjustable by the pot, and there's another chip that could be a MOSFET in SOIC package.


I would say you can use the PWM driver board and hook it straight up without additional inductance, but your input voltage must be the same as the voltage to drive your LED strip, otherwise if you wind the wick up too far you could blow your string.
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Offline zappedy

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Re: Driving LED with PWM speed controller or step motor driver?
« Reply #4 on: November 04, 2015, 09:42:09 am »
Thanks!

The EasyDriver step motor driver has current limiting though, wouldn't that work, if I set it to slightly below 700mA?
 

Offline tron9000

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Re: Driving LED with PWM speed controller or step motor driver?
« Reply #5 on: November 04, 2015, 09:50:52 am »
well yes, but that is $15 a board and you'd be only using 1/2 of the h-bridge and all that capability would be going to waste.

its like putting a Ferrari F40 engine in a generator.

if you want to limit the current to protect your string you could put an in-line fuse with your string.

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