looking for a kit or plans for electronics

[curtis rosche]

im looking for a kit to make a dc powersupply or dc motor controler with about 30 amps of output. or the plans to make one. does anyone know of a good place to get plans or a kit to do this?

[Steve Schlumpf]

Curtis - 30 amps is a heck of a lot of DC current! You sure you require that much juice? There are DC power supply kits available but even the bench top kits are only 5 amps or so.

[David G Baker]

Curtis,
HSC Electronic Supply in California has a lot of surplus electronic items, look them up on the Internet, give them a call or E-mail them and they may be able to help you out. They have several stores and they are a very good place to start. Let them know what you are trying to do.
I purchased a 50 amp peaking and 30 amp continuous power supply from them several years ago to power a DC linear apmlifier. The power supply was originally used in a automotive repair shop for testing electronic and electric devices and circuits in vehicles. I paid $40 for it

[curtis rosche]

it would be to run a dc motor. i know you can buy the device to do it, but i was wondering if anyone knew of any kits, so i can put it together for a class

[Steve Schlumpf]

Curtis - there are kits for sale online but you have to know the operating voltage - in addition to the maximum current - to find one that will work for your project.

[curtis rosche]

heres a picture of the plate on the motor. im not sure what i would need to look for based on these numbers. if i can find a scematic drawing for a unit that would work, i can always order the parts and make it myself.
sorry, i tried to upload the pic, but it isnt working, so heres a link to it
http://www.sawmillcreek.org/showthread.php?t=102021

[Rob Cunningham]

At work we order electronics stuff from Marlin P. Jones and Digi-Key. Not sure if they have what you want but it might be worth a look.

http://www.mpja.com/
http://www.digikey.com/

[Myk Rian]

That's going to take some whopping regulators for 30 amps. I made a PS several years ago that was capable of 12v @ 20 amps. I had to use the entire back of the thing for heatsinks.
Quite frankly, a car battery and charger would be the easiest and most reliable way to supply the power you want.
If you really want to build one, look for plans for a switching type of power supply. Or even use a computer supply.

[Rod Sheridan]

Hi Curtis, your motor is a 95VDC motor which is the correct voltage to operate from rectified 120VAC.

The motor current will depend upon the load applied to the motor, so if you're not loading it much you won't need a large controller.

Your best bet would be to pick up a surplus DC motor controller with a 90 volt output.

Regards, Rod.

P.S. Your motor needs an external blower to cool it.

[curtis rosche]

this was a treadmill motor, that will eventually end up on my lathe. does it need a blower, it didnt have one origianlly
so it will have a largeish load on it.
if its a 95 volt motor, wont i need to have at least that to run it?
i know its probably not the best path to go, but i am going to make it my self, so i need to find the scymatic and parts list to make it

[David G Baker]

Curtis,
I looked at the photos of your motor set up that you posted without reading the thread information and immediately recognized the motor as a treadmill motor. I had a treadmill that had relatively few hours on it that got damaged by the movers when I moved to Michigan from California. The motor was fine but the controller was damaged to the point that it would have cost me around 75% of the cost to buy a new treadmill.
I bought a new treadmill. I spent a lot of time looking at the motor and controller set up trying to visualize how I could utilize the motor. I did a lot of Internet searching to get educated on how to build a new controller. I finally gave up, put the treadmill back together, put it down by my mail box with a sign on it saying FREE but needs work. It was gone with in 30 minutes.
If you really enjoy complicated projects you are looking at one, let us know how it works out for you. If you decide not to go the complicated route there is a company that sells surplus motors, controllers,hydraulics, etc. I don't recall the exact company name but surplus is part of the company's name.

[Rod Sheridan]

this was a treadmill motor, that will eventually end up on my lathe. does it need a blower, it didnt have one origianlly
so it will have a largeish load on it.
if its a 95 volt motor, wont i need to have at least that to run it?
i know its probably not the best path to go, but i am going to make it my self, so i need to find the scymatic and parts list to make it

The motor is marked as needing an external fan, so it will need one.

The motor will run as a variable voltage motor, so the controller will be a phase angle fired DC controller.

You're best to find one from a treadmill or purchase a used DC motor controller for a 90 volt motor.

Regards, Rod.

P.S. I wouldn't use this for a lathe, I'd use a 3 phase motor and a VFD. I couldn't be bothered with brush/commutator maintenance.

[curtis rosche]

ok, so im looking for a 90 volt dc controller, how many amps should it be if this would be used continuously with a load?

[curtis rosche]

ok, so i found a couple things, but i have some questions.
this one comes as a kit, but it doesnt go up to the total amperage of the motor. http://www.electronickits.com/kit/complete/motor/ck1400.htm

there is also this one, but it doesnt have the right voltage, could this one be changed by just hooking it up to a different sized transformer? http://www.electronickits.com/kit/complete/motor/CKMX066.htm

[Rod Sheridan]

ok, so i found a couple things, but i have some questions.
this one comes as a kit, but it doesnt go up to the total amperage of the motor. http://www.electronickits.com/kit/complete/motor/ck1400.htm

there is also this one, but it doesnt have the right voltage, could this one be changed by just hooking it up to a different sized transformer? http://www.electronickits.com/kit/complete/motor/CKMX066.htm

Neither of those devices are what you are looking for, they both use DC as the power supply and they are too small in both voltage and current to run your motor.

You need a DC motor controller with a 120VAC input, start looking at surplus units as previously suggested.

Regards, Rod.

[curtis rosche]

i can build the rectifyer. that is easy. what happens if i get something that has a lower voltage and lower current, does it just have less performance?

[Windal Burton]

curtis

read this
http://www.diyelectriccar.com/forums/showthread.php/pwm-controller-design-sg3524-and-tc4420-13763.html?p=100728&posted=1#post100728

[Dave Johnson29]

I have a treadmill motor on my Jet BD920 metalworking lathe. I adapted it about 5 years back and it has seen many hundreds of hours use. I checked brushes about 3 months back and they were about 15% gone.

I had to add a fan and an adapter for the shaft as the lathe is Metric and the motor was inch.

I got a 90v DC controller from one of the surplus houses, can't recall which but it was about $60. Keep checking MPJ and surpluscenter for used ones. This is new and expensive and only 1hp for 90v...

https://www.surpluscenter.com/item.asp?UID=2009101709340562&item=11-2102&catname=

Just checked your pics again and the 2.56hp should be taken into consideration as the start up load. The controller will need to be able to handle that surge load for a second or two. Even using the figures supplied, 21.4A x 90v = 1926 W / 756 (W/HP) = 2.55HP

DC motors on start up from rest present an infinite load for a fraction of a second.