# AC & DC Motor Info Links



## Andrew_D (Feb 17, 2009)

Foozer's post on converting to DC (http://www.homemodelenginemachinist.com/index.php?topic=4210.0) reminded me of a website I found with lots of info on AC & DC Motors. 

http://www.sea.siemens.com/step/downloads.html

I've downloaded the PDF files and refer to them often. They don't help with hooking up your controller (unless it is a Siemens controller!), but there's lots of info explaining the types of motors.

I'm currently working on my own DC Conversion for my mini-lathe using a treadmill motor and was getting confused about the different types of motors: AC vs DC, Permanent Magnet vs Shunt Wound, etc vs etc.... ??? ???

Andrew


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## Kludge (Feb 17, 2009)

Andrew_D  said:
			
		

> Foozer's post on converting to DC reminded me of a website I found with lots of info on AC & DC Motors.



Yep, an excellent site (now that I've seen it) that explains a lot. Siemens has been around for quite a while and has a pretty good idea How Things Work. A good amount of my own knowledge has been from hands on experience (including letting out the smoke once or twice :-X ) and a little reading but this site explains a lot significantly better than I can. 



> I'm currently working on my own DC Conversion for my mini-lathe using a treadmill motor and was getting confused about the different types of motors: AC vs DC, Permanent Magnet vs Shunt Wound, etc vs etc....



If you have any further questions, please ask. I'll do all I can to help.

Best regards,

Kludge


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## Andrew_D (Feb 18, 2009)

Kludge  said:
			
		

> A good amount of my own knowledge has been from hands on experience (including letting out the smoke once or twice :-X ) and a little reading but this site explains a lot significantly better than I can.
> 
> Kludge



Yeah, I've let my fair share of smoke out of electronic components over the years. I've tried real hard, but it's tough trying to get all that smoke back into the tiny container it came out of! :big: Rof} I don't know how the manufacturers get it in there...they must have guys with bigger muscles than me!

Andrew


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## lathe nut (Feb 18, 2009)

Andrew, thanks for the site lead, I have just recently picked up a second 7X10 lathe and would like to change it over to what you are doing the motor on this one is in sad shape, it smokes after a little while of use, been looking for a replacement motor but don't want to pay what they are asking at the site that I found, keep us informed of the progress, thanks again, Lathe Nut


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## Bluechip (Feb 18, 2009)

Hi Lathenut

Wherefor art thou, Lathenut ??

I may have one .. got a DC motor 4 yrs ago, was told it was off Warco Minilathe 

I'm in Belper, Derbyshire, UK

Dave


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## Kludge (Feb 18, 2009)

Andrew_D  said:
			
		

> Yeah, I've let my fair share of smoke out of electronic components over the years. I've tried real hard, but it's tough trying to get all that smoke back into the tiny container it came out of! I don't know how the manufacturers get it in there...they must have guys with bigger muscles than me!



That's why the manufacturers have factories in the Far east where people have little hands. It's not muscle so much as tremendous dexterity at funneling it all into the devices in the first place then sealing them so it stays in place. They also have some fairly significant compressors which get even more powerful with each new generation of electronics. 

OTOH, the British have a really unique arrangement for some of their sports cars, the Lucas Replacement Smoke Kit which apparently is a big seller due to some undocumented features in the wiring of those vehicles. I haven't found anything to suggest this can't be applied to larger devices like motors, however I also haven't found anything to suggest a way to accomplish this. 

Best regards,

kludge


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## lathe nut (Feb 18, 2009)

Dave, I am in the USA or what is left of it, my lathe is the Harbor Freight 7X10, it is suppose to be 3/4 horse power I think if so it must be small horses, is yours that size, they show them on that little machine shop page, not sure how to post there web page, Lathe Nut


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## Bluechip (Feb 19, 2009)

Lathenut,

This is it. I was given it 'cos the guy who had the MiniLathe wanted a cheap machine to polish things [ he did fishing rod bits, I think ] so the motor was discarded in favour of a compressed air engine/turbine/motor whatever. This clocked about 12k RPM. I made him an electronic tachometer. He changed the mandrel bearings for a/c IIRC.
He went to Holland about 4 yrs ago, gave me a lot of bits in his clear out. Motor amongst them. Took his Wabeco 6000E though !! Could have donated it to me instead of lugging it to Holland. No sense of social responsibility some folk  

It says 250W which is 1/3rd HP nominal ..







But if you're in the US, it ain't much use to you [ or me, for that matter ]

Dave


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## Kermit (Feb 19, 2009)

Here is a link to a page of information I found interesting. The circuit he has made for variable pulse width generation is very ingenious and quite easy to make.

http://www.robotroom.com/PWM.html


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## Kludge (Feb 19, 2009)

Kermit  said:
			
		

> Here is a link to a page of information I found interesting. The circuit he has made for variable pulse width generation is very ingenious and quite easy to make.



It's also well written which makes even more so cooler. I took a look at his whole site and have it bookmarked for future reference.

Now to find a set of decent transistors to drive the watchmeker's lathe and sewing machine (and Unimat?) motors. 

Best regards,

Kludge


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## Kermit (Feb 19, 2009)

Kludge I'm sure YOU know this but some high wattage Thyristors triggered from a conditioned output of that simple PWM circuit will drive most any common 1 phase AC motor. (With proper tinkering, of course) 

Kermit


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## Noitoen (Feb 19, 2009)

As long as you don't rectify the current, you can use thyristors.(An AC motor doesn't DC) The modern soft starters use this technique. At the moment I have on my bench to repair, an old 3 phase motor speed controller that used phase angle control to vary the speed of a 3 HP motor (400V). To keep the speed stable they use a tacho-generator as feedback control. Today with the VFD's this is much simpler.


Helder


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## Kludge (Feb 19, 2009)

Kermit  said:
			
		

> Kludge I'm sure YOU know this but some high wattage Thyristors triggered from a conditioned output of that simple PWM circuit will drive most any common 1 phase AC motor. (With proper tinkering, of course)



Well, yeah. Except these are universal motors that will be running from DC. 

There are some pretty cool power MOSFETs that should do the trick fairly nicely, especially with a transformer I have that can become part of a fairly decent 120vdc, 2amp power supply - about twice the current any of my universal motors need. All I need to do is tie the 2N3904 (or whatever) to the MOSFET and all is wonderful. 

BEst regards,

Kludge


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