Is there an easy dc-dc step-up schematic?

[Gyvven]

I found some nice little steppers that I can't pass up at only $5 each. However, they require 65v (@ 1.25A).

I started researching dc-dc converters but haven't found anything that makes sense to me. I've made voltage regulators and I thought this would be something similar in reverse, but it's not.

Does anyone have any suggestions on a scematic, or even a particular IC I can get a data sheet on?

Thanks,
Gyv

[NC Cams]

Buy/make a transformer with the current/voltage you need.

Much cheaper and robust. A dc-dc converter that will put out the power you need will be expensive. Heck, you can easily find some old AT power supplies and daisy chain them to get voltage and amperage you need.

Do a search for "daisychaining PC power supplies" and follow the directions.

[Gyvven]

A transformer would be the easiest way to go, but I don't know all the terminology. I'm trying to get from 12v (or 24v, I have one of these sitting around) up to 65v.

How and where would I find one? I don't mind making one either. I found some information on it, but it's greek (geek?) to me.

If I make it, would I then multiply the number of secondary windings by 5.416 (65 / 12)? Is it that easy?

[Al_The_Man]

If you want to add turns to an existing transformer, which is easiest on a Toroidal type, BTW.
You would need to find out the Turns/volt, and the simplest way is to wind a small number on top of the existing secondary, say 5 or 10, and measure the resultant AC voltage, This will allow you to calculate the amount of turns you would need to increase the existing winding.
Remember that the resultant AC output will need to be .707 x your desired DC output.
Square lamination transformers are usually the hardest to increase because of the construction.
The other way is to get a closest value Toroidal type off ebay
Al.

[Gyvven]

OW, OW, OW! That just put a kink in my gray matter.

Are you saying that using a dc input current I'll end up with an ac output current? I've made power supplies for amps, but always using mains stepped down and rectified to dc, but my knowledge on dc electronics is pretty weak. I understand the bridge rectifiers and caps, but I was beginning to think that it would be a simple input-output formula. Am I misunderstanding something here?

[ViperTX]

What you're looking for is a Boost DC-DC Converter.

You have us all over the board guessing what sort of DC you're trying to boost. If you really want to research Switch Mode Power Supplies then search for SMPS and PWM controllers.

But your best bet is to follow everyone's advice of roll your own unregulated DC supply. Find a toroid with a a secondary output of around 48 VAC, get a bridge rectifier, and some Large can electrolytics.

Paul

[Gyvven]

Viper: You're correct, I'm looking for a simple dc-dc boost converter. Or, since it was mentioned and I hadn't considered it since I don't know much about them, an easy transformer solution. I didn't realize there was more than one kind of DC.

I did find this on instructables.

http://www.instructables.com/id/DC_t...t_Converter_1/

I have some old AT power supplies, and also a 24v 15A power supply that I can use. I'm just trying to find the best most cost effective way to power my steppers at 65v.

[valmet58]

why d'ont you find an old microwave and rewire the transformer secondary..
basically you remove the winding which contains the smaller wires.then you
rewire the secondary..1 turn of wire gives approximatly 1 volt..this is what i did
to power my 3 drives which are rated at a total of 15 amps..if you are interested make searches on the site and you will find that article

[Al_The_Man]

Originally Posted by Gyvven OW, OW, OW! That just put a kink in my gray matter. Are you saying that using a dc input current I'll end up with an ac output current? I've made power supplies for amps, but always using mains stepped down and rectified to dc, but my knowledge on dc electronics is pretty weak. I understand the bridge rectifiers and caps, but I was beginning to think that it would be a simple input-output formula. Am I misunderstanding something here?

What I said was, or thought I was saying, is if you modify the AC secondary, i.e. add turns, this increases the AC voltage which results in an increase in subsequent DC.
Multiply the AC by 1.4 to get the DC or conversely multiply the DC you want by .707 to get the AC you need.
I am talking regular linear supply here.
Al.

[Gyvven]

Just to show you how much a newb I am to this whole electronics thing here's what I found out; I don't need to run my motors at 65v, they'll be happy at 24v, so I don't need to a boost converter nor a transformer.

Isn't it fun to learn?

I won't be needing to do this, but I will file the knowledge away for future reference. I'll also continue to research and learn about transformers, especially that microwave transformer welder I saw. Ooh.

I apologize for causing anyone to pull their hair out, and thank you all for the assistance you've given.

Thanks,
Gyv

[NC Cams]

Yes they'll run "but" bit not necessarily "perform".

THe benefit of the higher voltage ist he you'll get better magnetic saturation and thus more "magnet" and thus more torque response. THis is/will be of benefit as you try to crisply accelerate the combined load of motor inertia and load inertia.

You really need to read Bob Warfied's site on steppers and stepper P/S's. NO need to reinvent the wheel.

Do a "Bob Warfield power supply" via the 'Zone's search engine.