Transformer Input Meanings

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John Schrader
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Transformer Input Meanings

Post by John Schrader »

I'm considering purchasing an xray transformer in eBay now that there seems to be some decent deals floating out and about.

Here's two I'm considering:
https://www.ebay.com/c/27013998742
https://www.ebay.com/itm/bennett-x-ray- ... SwpfpePByz

For the first, I assume P1 is the input power to the primary coil and P3 to the secondary coil. Can I just drive P3 & GND with my 220v variac. What does SHLD mean?

For the second I assume that mA on the top means mA test point with P1 and P2 being similar to the first one. What does high and low mean?

As an add-on these seem older much bulkier transformers - could they handle sufficiently being driven at 50 Hz from the variac or will they need higher frequency. I'm trying to avoid unpotting the transformer and simply using the mA test point w/ a fluke and my variac to confirm functionality.

Lastly what's the cable connection type for the anode and where can I find a suitable one online does anyone know?
Jerry Biehler
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Re: Transformer Input Meanings

Post by Jerry Biehler »

P1 , P2, or P3 are your primary connections. SHLD is shield, the shield on the cable supplying the power to the primary. If there is a shield it might be a high frequency drive transformer which you will need to either get or build a drive for it. With the physical size of both being so small I would be very surprised if they were not HF transformers.
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Rich Feldman
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Re: Transformer Input Meanings

Post by Rich Feldman »

Agree with Jerry that the smallness implies high frequency. Compare size not with bare dental transformers (7 to 15 mA in 1-second bursts), but with potted 100 to 200 mA transformers for whole-spine radiography.

I can attest that the Bennett cathode and anode tanks need HF drive, in fact are designed for 100 kHz (!).
See my thread here viewtopic.php?f=18&t=9781
and that of Muhammad Faidzul, who made a driver for an identical-looking tank.
viewtopic.php?f=18&t=11088
bennett.jpg
The tank in your second ebay listing is one for anode side, so HV polarity is positive. You would have to open it up and reverse a bunch of diodes -- see picture in my thread.

Ask the ebay vendors if the tanks come with HV cables; they might have those in another auction. Nothing you can't scratch build, for fusor work.

Just noticed a pair of Bennett inverter modules on ebay, and might make an offer.
https://www.ebay.com/itm/Bennett-PC-Boa ... Sw5cNYilF2
All models are wrong; some models are useful. -- George Box
John Futter
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Re: Transformer Input Meanings

Post by John Futter »

John Should also do as the rules state
This is not the place for your first post
John Schrader
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Re: Transformer Input Meanings

Post by John Schrader »

This transformer seems like it'd be a much better fit if I don't want to have to worry about high frequency driving then?

https://www.ebay.com/itm/RIGAKU-9547-52 ... Sw9fZetK0J
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Rich Feldman
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Re: Transformer Input Meanings

Post by Rich Feldman »

Still haven't seen anything about you in Please Introduce Yourself forum.

If you are grown up and experienced with ebay, then I guess you are prepared to pick up that big old Rigaku thing in Oxnard, California.
And know better than to offer more than half of the buy-it-now price ( seller has the option of counter-offering ).

My Bennett cathode and anode tank set came from ebay for less than $100. Less than $150 with tax and shipping.
Pretty expensive paperweights and door stops while in my custody, after a flurry of measuring and learning more than 5 years ago.
All models are wrong; some models are useful. -- George Box
John Schrader
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Re: Transformer Input Meanings

Post by John Schrader »

Didn't get around to it yet but I just tossed a post up.

I offered $300 for it - it's 6 hours drive for it but if it comes through I can drive down for a weekend and pick it up. $300 to get something that could work / do some interesting experiments off the bat seems like a solid deal.
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