Power for DC motor controller

I bought one of these 24v DC motor controllers:

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It came with zero documentation. I found the basic connections on the web, but nothing else.

My question here is: it takes 12-24v DC in and with just a variac and bridge rectifier, it works. But would it work better with a regulated supply? I'm guessing not because of its own big cap and PWM output. But what do I know. If regulated would be better, in what way?

I don't want to just add caps because it will have very intermittent duty and the fully-charged cap voltage would be way over the controller's rated 24v.

Thanks, Bob

Reply to
Bob Engelhardt
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Usually the motor controller will work better. As the speed slows down the PWM will give much more tork at the low RPMs.

Reply to
Ralph Mowery

Thank you. It's the low speed that's most important in this case.

Reply to
Bob Engelhardt

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** The controller ideally should be supplied by a battery pack, a hefty SMPS or a transformer based DC supply with about 30,000uF of smoothing.

.... Phil

Reply to
Phil Allison

The website says it is a PID controller. That's probably way more sophisticated than you need or want. Do you have some tachometer feedback signal? (and do they provide enough info so you can tune it for your motor and load?)

With all the extra connections, and board mounted switches, looks like it could be tricky to apply.

Reply to
default

"... enough info ...? Zero, zip, nada ... that's the problem.

Reply to
Bob Engelhardt

Thanks ... that's 2 yea & 0 nay. I'm sure there's the parts in my "collection" for a regulator.

Reply to
Bob Engelhardt

If it is a DC motor and you have a DC supply I'd go with a simple PWM. You can't filter the output of those, it defeats the purpose of chopping the power to control speed...

A better solution is a variable output switched mode power supply then you can filter and send smooth DC to the motor and hang all the caps you want on the output if you want a "stiff" power supply.

El cheapo PWM:

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article on modding a SMPS for variable output:

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off-the-rack variable DC supplies:

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I've got a cheap "battery eliminator" style PS that I got on Ebay for ~$20, it only outputs 3-12V in 1.5V increments at 5+ amps. It would be child's play to make it continuously variable, just put a potentiometer in place of the rotary switch. Then it would need a meter and be less useful for what I use it for, so I haven't done it.

Reply to
default

Yeah, but ... I already HAVE the subject controller! I went for a more sophisticated controller because of the extremely variable motor's run conditions: it will run at low speed with no load, then a minor load will be added, then a major load. I need the speed to stay more-or-less constant through these changes & not have to be diddling with it.

Reply to
Bob Engelhardt

Understood. A PID controller can be tuned for load and the regulation response can anticipate the power needed to maintain a set-point. To do that it needs feedback so it knows what the RPM is, then it has to be tuned to your system.

The scant information supplied does say it is for closed loop speed control, and the info seems to suggest that can be an analog or digital feedback. You don't mention if you have some form of feedback.(?)

Short of finding the manufacturer and getting some more info, I wouldn't know what to tell you.

I wouldn't be too crazy about PID control, any closed loop control scheme should be able to maintain precise speed control.

Also you mention it will run at low speed. Geared motors are better choices as a rule. 180 watts is ~1/4 HP or less.

Reply to
default

Maybe you could Google the part number on that black square chip for a datasheet? Or did the seller sand that off?

Michael

Reply to
mrdarrett

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