Toroid Power Transformer, 250va, 36vct/7a; $38

These are brand new NOS high-quality 250VA Toroidal power transformers custom-made by Nicollet Technologies in Minneapolis, Minnesota.

They're still in their factory packaging, as shown in the 2nd picture.  I opened one briefly to shoot the close-up shot.

This part is rated for continuous 24/7 operation at 250VA, peak 500VA; with a main output winding of 36vac @ 7 amps; which makes a very useful output of about 48vdc at no-load and nominal line-input.  Input is dual 115/230vac primaries.

But unlike the usual off-the-shelf toroids, these also include a very handy additional Auxiliary secondary, to run all your low-power control/preamp circuitry.  See below.

These high-quality transformers are excellent for DIY-Audio, CNC Servo/Stepper Motor Drivers, Power-FET RF Power Amplifiers, etc..

NOTE:  Although this part does not have a center-tapped main output, it would be very easy to mount a pair of them, and have a beefy 500VA 68VCT output; plus TWO sets of auxiliary windings!  It might look pretty cool too....<g>




This part will supply 5-6 amps of DC at 48v all day long.  I had a 'used' one which I wired up as a trickle-charger for the 2,500 lb 36vdc forklift-battery in our off-grid power system.  The battery draws 10-11 amps from the charger, which is way overloading this 250va part; yet it has run many 2-3 hour sessions of that without complaint (every few days when I run the diesel gen-set).  It gets fairly warm under that 200% overload, but not so hot that I can't keep my hand on it as long as I want.  Pretty good for a 250VA rated part!

Here's a picture of one still in the factory-packaging, and also showing the typical mounting hardware used for these....

(note;  I have just a few sets of this hardware; which I'll include with your toroids if you ask for it.  If you're going to mount them differently, please leave the hdw. for someone else)




NOTES:

- There is a very handy 2nd auxiliary-output winding for low-power control circuitry.  As I recall, it was designed to make +/- 12vdc regulated, and +5 too I think.  But don't quote me on that.  I'll get this winding measured in the next few days, and add the ratings here.

- It may be possible to re-wire the main secondary winding as a 68vac center-tapped winding.  Although the main secondary winding does not provide an external center-tap connection; it's possible that it is in fact not a single heavy-gauge winding, but a pair of lower-current windings in parallel.

Many high current toroid-windings are actually wound as a "bifilar" pair of lighter-gauge windings (for easier winding), and then connected in parallel under the tape.  IF these parts are made that way, then you could cut the outer-tape open, cut apart the paralleling-connections, and reconnect the two windings in series and bring out that new center-tap externally.  You'd then have a 68 VCT winding good for just under 4 amps continuous.

I AM NOT GUARANTEEING THAT THESE PARTS ARE WOUND THAT WAY.  I'm only saying that many toroids are wound that way, and these MIGHT be.  But they may not be, since 5-6 amps is right at the 'edge' of the wire-size where manufacturers tend to switch to bifilar construction.  So these might or might not be.  I don't want to cut open a brand-new $80 transformer just to find out!...lol.


- Shipping Weight;  about 6 pounds.

- As of Jan. 18, 2009, I have only half a dozen of these left....they're all brand new, never used, still in factory-wrapping, as you can see in the pic.....but have been in storage for a few years, which affects the surface-finish a tiny bit.

I believe these are currently over $80/each in quantity 10-up from the factory.

I'll sell one for $38, or a pair for $68, plus shipping.

(and I don't charge any of those BS extra 'handling' fees like on ePay either...)

If you want all six that are left, I'd take $195 for the lot.

To make it a "done deal", email me at: "metal at fullwave dawt com"

Terms: 

Payment:  Cash, Check, or Paypal; email me for details to make payment

Shipping:  Whatever it costs me....and no BS extra fees for 'packing' or 'handling'.

Response Time:  We live in the mountains now, and my wife gets into town a couple times a week for mail and groceries (I don't drive much any more, since my vision is failing).  Expect about a week between receipt/clearing of your payment and when the carefully-packed instrument is dropped off at the UPS terminal or Post Office in Medford, Oregon.

Go back to my full list at:  Selling my entire Electronics Shop....TEST EQUIPMENT, etc..