By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Forum House Ad Zone

Power supply/speed control

All Topics | Latest Posts

Search for:  in Thread Title in  
Gordon W26/05/2014 10:42:28
2011 forum posts

Original post by Martin Perman

"Gentlemen,

I want to put power feed on both my Centec 2A Horizontal milling machine and my mill drill, I intend using an ex wiper motor on both.

Can somebody point me in the direction of drawings so that I can build a mains supplied power supply with a speed control.

Thanks,

Martin P"

 

 

 

Yes please, and if at all possible without strings of initials. Letters and numbers to identify parts to be ordered will of course be useful. Sorry if I'm hijackig your thread Martin.

Edited By JasonB on 26/05/2014 16:10:03

Bob Brown 126/05/2014 11:09:56
avatar
1022 forum posts
127 photos

Simple pulse width modulation (PWM) controllers are probably cheaper to buy already built, then just add a 12v power supply.

martin perman26/05/2014 12:06:13
avatar
2095 forum posts
75 photos

Bob,

Thanks for that, I have just had a quick look and you can get a 10A unit for £10.00 or less, its not worth the effort of making one, power supplies are cheap enough as well.

Martin P

Les Jones 126/05/2014 12:16:47
2292 forum posts
159 photos

Hi Martin,
I agree with Bob's comments especially if you are not already into electronics. You will find many PWM speed controllers on Ebay. The first step is to find out how much current the motor draws while driving the table. I would choose a controller with a current rating at least 50% above the motor current. For the power supply you could probably use a battery charger of suitable rating with a capacitor of about 4700 uF 25 volt rating across its output. You could use a switching arrangement similar to Mike Cox's design here. I just use a three position switch for forward - stop - reverse and a push button switch to override the speed control so it runs at full speed when pressed.

Les.

martin perman26/05/2014 12:43:33
avatar
2095 forum posts
75 photos

Les,

Thanks for that as well, I had worked out stop, start, fwd and rev as I'm a mechancal engineer with electrical abilities it was just the speed control that without help is slightly out of my reach, but as I often tell apprentices it could only go bang once smiley

Martin P

Bob Brown 126/05/2014 12:49:03
avatar
1022 forum posts
127 photos

"it could only go bang once "

As written in engine manual of Japanese origin translated to English, "press button marked start till engine explodes"laugh

Gordon W26/05/2014 14:39:12
2011 forum posts

I've just been looking at the net, and speed controllers are cheap, but not so the power supply, guess that's down to the transformer, it seems the way to go. Takes the fun out of it tho'.

martin perman26/05/2014 15:58:14
avatar
2095 forum posts
75 photos

Gentlemen,

I've just notice my original post has gone,can somebody tell me why and how please, I know that in the title all the letters were there but not necessarily in the right order but couldn't find how to correct it.

Martin P

JasonB26/05/2014 16:02:45
avatar
25215 forum posts
3105 photos
1 articles

This is the same thread but I corrected the title. Only Moderators can edit these things.

 

Though I have just noticed your original post has gone AWOL some time after I corrected the title? Have managed to find the text but had to put it in Gordons post. Best I can do.

J

Edited By JasonB on 26/05/2014 16:04:32

Edited By JasonB on 26/05/2014 16:10:49

martin perman26/05/2014 16:35:35
avatar
2095 forum posts
75 photos

I was only curious,

Martin P

Neil Wyatt26/05/2014 20:42:07
avatar
19226 forum posts
749 photos
86 articles

Managed to completely confuse me, has no-one any idea where that post went?

I've seen a few examples of duplicate postings over the last couple of weeks, but not disappearing ones.

Neil

JasonB26/05/2014 20:59:03
avatar
25215 forum posts
3105 photos
1 articles

Only thing I can think of is that another mod tried to edit the original post in the admin area ( it was reported to ask for the spelling to be corrected in the title) any editing in the admin area can loose the post. I have talked to Katie about this before but don't know if it was sorted.

I acted on the report and altered it via the edit tab at the top of the thread so could not have been that. Then deleted the report as it had been dealt with, the report has gone so it must have been that I deleted and not the opening post. Luckily I had ME open in a few tabs and was able to go back and find Martin's post which I copied and pasted into Gorden's post as thats the only way to keep cronological order.

J

Oompa Lumpa27/05/2014 04:50:21
888 forum posts
36 photos

How about the power upply from an old computer? At least regulated and smoothed.

graham.

Gordon W27/05/2014 09:44:03
2011 forum posts

Hello Martin, I feel guilty now , not that I had anything to do with your post getting lost. I have found a biggish transformer with 24V output, wire is about 1mm thick so should be ok for a few amps. I would like voltage control with meter etc. All the circuits I've found on the web seem over complex, can we still buy a full wave rectifier and variable resisters? Or is it cheaper to buy the integrated circuit stuff? I will buy a completed speed controller, no point in trying to make one.

Ian S C28/05/2014 15:23:06
avatar
7468 forum posts
230 photos

The transformer that I use for my power supply comes from an old Zerox copier, it's about 6"cube, I found it was an auto transformer, so I wound another layer to give an isolated supply at 18 volts, I used double winding of either 18 or 20 SWG wire (can't remember). Ian S C

mechman4817/06/2014 12:27:05
avatar
2947 forum posts
468 photos

Help !

I am looking to fit a power feed to my WM 16 table, I have a 12v wiper motor, a Potentiometer for speed control & a DTDP switch for Fwd -Off- rev but am looking to fit a 240v AC - 12v DC transformer for the supply as I don't have a battery charger (pinched when low life got into my garage) I would prefer to have a 'wall wart type.. simply plug into 13 amp socket connect to DTDP & away it goes..so to speak..am I on the right track & what type of transformer (Wall wart) would be suitable? I am assuming that I could remove the round pin connector from a cheap wall wart & connect to the DTDP... or maybe Maplins have a connector.. if you get my drift

I have looked on e bay & there are hundreds to pick from... confusing.. I looked particularly at ..

**LINK**

is this feasible/suitable considering it says it is a LED driver?

I don't know what amps the motor will draw when connected to the leadscrew as am in the dark as far as electrics / electronics goes., I want to K.I.S.S. in assembly & not looking for 'spaghetti junction' set up. I'm sure that some of you Electronic whizz kids could help.

TIA

George

Les Jones 117/06/2014 12:48:59
2292 forum posts
159 photos

Hi George,
I do not think you will find a "Wall Wart" type power supply with a large enough current rating to drive a wiper motor. I also think the LED power supply will not give enough current. (By the way your link does not seem to work.) I would guess that the motor will take about 5 amps but you should measure it before ordering any parts. Use a car battery and an ammeter. Just using a potentiometer for speed control will give very poor speed regulation. A PWM speed controller would be much better.

Les.

John McNamara17/06/2014 13:58:58
avatar
1377 forum posts
133 photos

I believe computer power supplies can provide +12 volts at a lot more than 5 amps (But not at the -12 volt output also provided)

There is a lot of information on the net

Regards
john

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Sign up to our Newsletter

Sign up to our newsletter and get a free digital issue.

You can unsubscribe at anytime. View our privacy policy at www.mortons.co.uk/privacy

Latest Forum Posts
Support Our Partners
cowells
Sarik
MERIDIENNE EXHIBITIONS LTD
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest

 

Donate

donate