transformer sources

[thielert]

I would like to build myself an unregulated DC supply. I see several of you veteran CNCers are using large toroidal transformers in your supplies. I wish to make a 32V ~35A DC supply. I have looked at several transformer manufacturers and can’t find one that suits me. Can anyone point me in the right direction?


Thanks,
Tim T

[NeoMoses]

I seem to remember seeing some at www.digikey.com. Watch out, they're pricey!

Also, www.mpja.com has some inexpensive rectangular transformers that might work for you.

[rdudley]

Just one place, www.plitron.com I've used several of them. Pick you size from their chart and call an order in!!!

[HomeCNC]

I must agree with rdudley. I have ordered many from them. I really like them.

It may take a little more time to get them because they make them as they are ordered. Also keep in mind that you get two transformers in one. Just connect the output in series to double the amps. You may need to order the 20 AMP toroid and double the output to get 40 Amps!

[turmite]

I can't get the link to work! "this page not available"

[rdudley]

If you could tell me what voltage you need and what amperage is required, I'll look up the number of the transformer you should use and post it with a diagram of the power supply circuit with sizes of the filter caps and bleeder resistor along with the rectifier bridge parameters.

Best to get it right the first time!!!

[rdudley]

Sorry, link is http//www.plitron.com .................

[CNCadmin]

Originally posted by HomeCNC I must agree with rdudley. I have ordered many from them. I really like them. It may take a little more time to get them because they make them as they are ordered. Also keep in mind that you get two transformers in one. Just connect the output in series to double the amps. You may need to order the 20 AMP toroid and double the output to get 40 Amps!

Which one are you using?

[starCNC]

Originally posted by HomeCNC I must agree with rdudley. I have ordered many from them. I really like them. It may take a little more time to get them because they make them as they are ordered. Also keep in mind that you get two transformers in one. Just connect the output in series to double the amps. You may need to order the 20 AMP toroid and double the output to get 40 Amps!

List some information about your power supply and some pictures please

thank you
StarCNC

[CNCadmin]

Here is good one- http://www.mpja.com/directview.asp?product=6645+PS

[ToyMaker]

Jeff wrote:
>Just connect the output in series to double the amps.<

Isn't that the other way round, windings in series add voltage and in parallel add current? Or am I confused (again )?

robotic regards,

Tom
= = = = =
"I guess you could say this treatment really whacks a polyp."
- - a doctor reporting on the effectiveness of a procedure

[Al_The_Man]

Originally posted by ToyMaker Jeff wrote: >Just connect the output in series to double the amps.< Isn't that the other way round, windings in series add voltage and in parallel add current? Or am I confused (again )?

Tom, your right, windings connected in parallel to double the current. Probabally a slip of the keypad by jeff.

Another thing to keep in mind with Toroidal transformers was illustrated by a call I had from a friend of mine who I had designed a supply for, he picked up a used Toroid txr from ebay and after he hooked everything up and powered up, he blew fuses and the transformer got hot, thinking he had a dud transformer, he called me to take a look.
I noticed right away he had made a mounting bracket for the transformer, because it did not come with one.
He had made a horseshoe bracket over the whole txr and secured it with a long screw through the centre.
What this effectively did was to provide two shorted turns around the toroid causing the over-current.
luckily no permanant damage was done.
Al