[FLUTE HEAD]

HELLO ALL, DOES ANYONE KNOW WHERE TO FIND TRANSFORMERS. Particularly
in a wide range of sizes. How about one with these specs: 20vac secondary with 12-15 amps output. I ordered from Plitron, but wow, 4 weaks. Places I've searched include Mouser, digikey. thanks matt

[cncadmin]

http://allelectronics.com maybe?

[cncadmin]

nevermind they only go up to 5A

[cncadmin]

he has 20a transformers "power supply 36V 25A $125 ( email me at [email protected] I do not want to sell power supply kits to unqualified people." http://www.seanet.com/~dmauch/

[FLUTE HEAD]

THANKS, I'LL TRY TO E-MAIL HIM ABOUT ONE. I can't believe how hard it is to find these.

[marvinstov]

I have a Plitron that might work for you. I could sell it for $60.00, you pay the shipping. It is Plitron #757027201. Check it out and let me know. It's new, never used.

Marv

[marvinstov]

Oh yea, I just built another transformer, a kit from Toroid.com. They come with the primary done, all you do is calculate the secondary and buy your own magnet wire and make the secondary. It is a little cheaper than buying one already finished but fun if you are looking at learning something about calculations for transformers. Comes with formulas for calculating what you need for the secondary. Only takes a couple hours to calculate and wind it.
The one I offered in the previous post is a real piece of work, center is potted, best looking toroid transformer I have ever bought.


Marv

[FLUTE HEAD]

Sounds Like 20v Secondary @ 20 Amps Output. Where Are Located At? (for Shipping Reasons)

[marvinstov]

I'm located in Florida. I believe it is 20 VDC at 20 amps wired in parallel. There are two primary windings and two secondary windings. The only thing I have done is power it up and test the voltages.

Marv

[FLUTE HEAD]

Appreciate the offer but I wanted to get closer to the mximum volts of my driver which is 35. Wanted somewhere around 28vdc. Hey Marv, what are they calling the toroidal trans on toroid.com? There were alot of different types. I tried to look into there standard transf., just to purchase one but kinda got confused. Oh, heres a thought, what about some of those "harbor freight tools" .com battery chargers. You can get some 24v 12 amp output for like $40.00. Know anyone thats used a battery charger? thanks matt. Someone else on this site also mentioned a microwave.

[marvinstov]

That's ok. You mentioned a 20VAC transformer in your initial post. I got a 400 VA transformer kit (toroid) from Toroid.com and wound the secondary last night for 28VAC, gave me 37.7 VDC with the bridge and cap. Magnet wire cost me $21 (12 AWG) plus shipping for 50 ft. Only used 40ft. You would probably want a bigger one for the amps you need. Toroidal refers to the shape of the transformer. Donut shaped compared to the regular square ones. Toroid.com seems ok. Took about 4 days to get the kit. Don't remember what the shipping was but came UPS Ground. I haven't tried a battery charger but I'm sure you could modify the transformer in one to work for you. I have been reading up on the microwave transformers and most people take out the secondary winding because it is really high voltage (some around 8,000), and rewind the secondary to suit their needs. I just got one to play with and they are about the right size for a good power supply but seem like a lot of trouble to make them work for the voltages we are looking for. Fun to play with though as long as you are VERY careful with the high voltages. If you change your mind, let me know, I don't have any plans for this one.

Marv

[FLUTE HEAD]

The 20vac is, from what I understand, the callout for the secondary. This number times 1.4 will = the output voltage of the transformer in volts DC. Hope this is correct

[marvinstov]

Right, actually 20 * Sq Rt of 2 (1.4142) = 28.284 VDC - approx 1.4 volts for bridge and cap would be 26.88 VDC. It actually works out to a little more than that at my location because the line voltage averages 122 VAC instead of the 115 VAC that Plitron uses in their computation.

[marvinstov]

Maybe you should look for a 22 VAC secondary, Plitron has them. That would give you about 29.7 VDC. I bought a 24 VAC from Allied and unwound a couple of turns to get it where I wanted it.

[HomeCNC]

I found a different transformer company (local USA) that stocks all the same Toroids as Plitron. I'm at work and don't have the link but I can post it tonight.

[marvinstov]

Jeff,
That's great. Is the quality the same? Seems like the Plitron transformers are really built good and built to last. Of course How much wear and tear can there be on a transformer once you get it installed?

Marv

[FLUTE HEAD]

HEY HOME CNC, If its this one, they wouldn't sell to individuals just commercial.link

[HomeCNC]

here is is.

http://avellindberg.com/transformers...mers_index.htm

I have not tried them but the specs look exact to Plitron. And I was told that they have them in stock.

[vladdy]

A toroid is definitely a better transformer than most iron wafer core styles as far as performance, especially if the end use is going to something with some finished value.. On a hobby MDF router I used a X'frmr from an old 24v battery charger found at the scrap yard.. got driven over by accident and scrapped.. internals were fine, total cost $2 [cdn even]... puts out around 33 volts, load tested to 50A and held at over 30v yet, so good enough..
for size, the top of the MDF in the photo is 8 inches..

[marvinstov]

Those look good Jeff. Have you checked on their prices?