Is my xray transformer a ferrite core and how would I drive it?

[nielsquake]

I have bought this transformer for a reasonable price and I was unable to find much using the product number: 451210494553. I know where the HV outputs are but I have no clue if this is even a ferrite core type transformer. I have a 1500w zvs driver and I was wondering if this would do the trick to run it. Does anyone know how to read this pinout and know which pins correspond to the primary of the top output? Also I want to know if this is a ferrite cored transformer or an iron core

[Mads Barnkob]

Hi Niels and welcome to HVF!

From the look of it, it is a modern ferrite core transformer, seems newer than any I have found.

It is about as big as one that I found in a 70 kW system that had two SKM400 IGBT brick inverters, it was either running them interleaved or just one for low power and two for high power, I am not sure.

What DC resistance measurements do you get between X1001, 1002, 1003, 1004?

It could be two primary coils as some of the transformers are divided in a positive and negative part and the mid-point is grounded. The mid-point would in that case be a bridge through which you measure the output current, as it is at ground potential there is no problems with measuring it with a simple shunt resistor.

The voltage feedback interfaces are more modern than what I found, but you properly just have outputs for negative and positive voltage, temperature and pressure in the tank.

[nielsquake]

Hi Niels and welcome to HVF!

From the look of it, it is a modern ferrite core transformer, seems newer than any I have found.

It is about as big as one that I found in a 70 kW system that had two SKM400 IGBT brick inverters, it was either running them interleaved or just one for low power and two for high power, I am not sure.

What DC resistance measurements do you get between X1001, 1002, 1003, 1004?

It could be two primary coils as some of the transformers are divided in a positive and negative part and the mid-point is grounded. The mid-point would in that case be a bridge through which you measure the output current, as it is at ground potential there is no problems with measuring it with a simple shunt resistor.

The voltage feedback interfaces are more modern than what I found, but you properly just have outputs for negative and positive voltage, temperature and pressure in the tank.

Hey, thanks for the response. My multimeter is busted right now but at least knowing I got a ferrite core one assures me that I can probably get it working with the propper equipment. Would a 50khz zvs driver work to power it? 

[Mads Barnkob]

From what I have observed in the xray inverters I have taken apart, they have a large 3-5uF capacitor in series with the primary winding, effectively acting as a DC blocking capacitor as its not driven at the LC resonant frequency and that is how the output voltage is controlled, by changing the drive frequency and the current by the on-time or pulse train lengths.

I would guess that 50 kHz is in the high end of what these are designed for, but that is merely a guess.

Maybe there is some information of value to you from this Steve Ward project: http://stevehv.4hv.org/ccps1.htm

[nielsquake]

Okay, So the circuit blocks signal that are not high frequency then? I am looking into doing some trial and error with this after I get a new multimeter and I hope to get it up and running using one of those high wattage chinese drivers. I got this transformer from a medical supply company by doing some sweet-talking and I think I got pretty lucky so I wouldn't want to ruin it.
The coil itself has never been outside of the oil so am I right in assuming that hooking it up to a ZVS that is powered under 1000w wouldn't burn any of the internal components or mess with that DC blocking cap you were talking about? This whole thing is pretty advanced from what I normally do (Primarily using NST's and flybacks with the 505 timer circuit) I have powered TV flybacks with a ZVS and I think the same principle goes for these big flybacks right?
I want to be able to drive a full 1000w into it and I really don't want this baby to break. It just looks so epic and I can maybe one day use it to do some DIY magnetron sputtering so I can examine objects from home with the SEM at my uni

[Mads Barnkob]

The series capacitor is outside of the tank, it is part of the inverter. You can see them sit in series with the primary output leads from the two IGBT full bridges in this setup: http://kaizerpowerelectronics.dk/tools/file-archive/?drawer=images*junk_yard_stuff*2015_12_23_-_xray_philips_optimus_65

This x-ray transformer is designed for 65 kW input power, 1 kW can still do damage if you connect it wrong, I still think you have a very similar transformer to the one I found there, where it used two full-bridge inverters.

[nielsquake]

The series capacitor is outside of the tank, it is part of the inverter. You can see them sit in series with the primary output leads from the two IGBT full bridges in this setup: http://kaizerpowerelectronics.dk/tools/file-archive/?drawer=images*junk_yard_stuff*2015_12_23_-_xray_philips_optimus_65

This x-ray transformer is designed for 65 kW input power, 1 kW can still do damage if you connect it wrong, I still think you have a very similar transformer to the one I found there, where it used two full-bridge inverters.

So the IGBT inverters generate the high frequency? Do I need to supply the main input pins (X1001, 1002, 1003, 1004) with just straight DC or pulsed DC or AC? I'm still pretty confirmed. I'm new to this. I just bought a new multimeter so when I get or I can get you the resistance of the pinouts. I currently only have a DC power supply of 150w so I'm not sure if that is even high enough to provide any output al all. Is there any foolproof way to power one of these that is pretty straight forward for someone like me that's lacking a lot of knowlage about these kinds of circuits

[Mads Barnkob]

The contents of the xray transformer tank is rather basic. It is a split step-up transformer with high voltage rectifiers and a voltage multiplier output stage.

The drive frequency is from the inverter and its driver circuits. The output of such a inverter is a pulsed DC square wave of some frequency that will result in a AC sine wave in the LC circuit of the capacitor in series with the primary coil.

You should be able to drive this with a ZVS driver, you could always add something in series with the main supply to limit the current, like a heating element or bulb. Something like a simple TL494 driver could also be a good way to experiment with low on-time and duty-cycle: http://kaizerpowerelectronics.dk/high-voltage/tl494-flyback-driver/

Getting the full potential out of this transformer will however require a large inverter with a serious DC bus to deliver pulses of 65 kW, considering you most likely only have 3x400VAC at 16A available.

A multimeter is great to check things, but to troubleshoot driver and inverter for a project like this (safely) you need a oscilloscope, current transformer and differential probe.

[nielsquake]

I found out this is a 2 tube transformer so I think it contains 2 full-on flybacks. The 4 pins must correspond to the 2 primarys for those I think.

The contents of the xray transformer tank is rather basic. It is a split step-up transformer with high voltage rectifiers and a voltage multiplier output stage.


The drive frequency is from the inverter and its driver circuits. The output of such a inverter is a pulsed DC square wave of some frequency that will result in a AC sine wave in the LC circuit of the capacitor in series with the primary coil.

You should be able to drive this with a ZVS driver, you could always add something in series with the main supply to limit the current, like a heating element or bulb. Something like a simple TL494 driver could also be a good way to experiment with low on-time and duty-cycle: http://kaizerpowerelectronics.dk/high-voltage/tl494-flyback-driver/

Getting the full potential out of this transformer will however require a large inverter with a serious DC bus to deliver pulses of 65 kW, considering you most likely only have 3x400VAC at 16A available.

A multimeter is great to check things, but to troubleshoot driver and inverter for a project like this (safely) you need a oscilloscope, current transformer and differential probe.

Thanks this really helps a ton

[nielsquake]

I did the resistance measurements of the inputs and it turned out to be 1.4Ω between X1001 and X1002 and 0.6Ω between X1003 and X1004. Given that the measurements were possible I assume this means I can drive it straight with a ZVS connected to X1001 and X1002 without much of a hassle right? I imagine these correspond to the output of the secondary that already has the HV Xray standardized connectors installed as this seems like the main one just judging from how the device looks and I imagine this one should have the largest resistance on the input.


As you seem like one of the most knowledgeable people on this topic around here on the internet I would love to hear your opinion on if this would work Kaizer.

I made a video that I also show the device in if you're interested

[Mads Barnkob]

Could you get a reading between X1002 and X1003? and what about between X1001 and X1004?

I really wish I had gotten some pictures of the inverter connections of that large system I found, but I got nothing.

I found this short video and it seems there is only two primary wires going into the terminal housing of the transformer

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You could be lucky to find a manual that can give you hints of the connections, somewhere among there, despite most of it is older stuff: http://www.frankshospitalworkshop.com/equipment/x-ray_service_manuals.html

[nielsquake]

Could you get a reading between X1002 and X1003? and what about between X1001 and X1004?

I really wish I had gotten some pictures of the inverter connections of that large system I found, but I got nothing.

I found this short video and it seems there is only two primary wires going into the terminal housing of the transformer

/>
You could be lucky to find a manual that can give you hints of the connections, somewhere among there, despite most of it is older stuff: http://www.frankshospitalworkshop.com/equipment/x-ray_service_manuals.html

No readings between those pins, I tested all combinations and those were the only two places I could get a reading including the grounded exterior of the transformer case.
Those resources are a very nice find. That video seems to be almost exactly the same type so that's lucky. No luck finding a manual though, I've tried but I couldn't come up with anything. I keep wanting to just hook it up and try but burning out the coils is the last thing I want so I'll just continue learning about how this all works internally. I contacted a US based supplier and they aggreed to take one apart for me and get the components out of the oil. The guy will send me pictures from all sides and will try to confirm a few things for me so when I get those I'll share them here.
What would you say is the minimum ammout of power a DC power supply should have to power the ZVS and in turn this transformer?

[nielsquake]

I also found this pic

[Mads Barnkob]

No readings between those pins, I tested all combinations and those were the only two places I could get a reading including the grounded exterior of the transformer case.
Those resources are a very nice find. That video seems to be almost exactly the same type so that's lucky. No luck finding a manual though, I've tried but I couldn't come up with anything. I keep wanting to just hook it up and try but burning out the coils is the last thing I want so I'll just continue learning about how this all works internally. I contacted a US based supplier and they aggreed to take one apart for me and get the components out of the oil. The guy will send me pictures from all sides and will try to confirm a few things for me so when I get those I'll share them here.
What would you say is the minimum ammout of power a DC power supply should have to power the ZVS and in turn this transformer?

That is nice, often it is very hard to get information from the companies on single parts without a service agreement.

You could properly power this from 50-100W at a very low duty-cycle, will get you some high voltage at very low current. The transformer you have is a beast and it will easily eat 65-100 kW peak, so continuesly (5-10 minutes) it could properly run 10-20 kW without cooking the oil, see if you can find the temperature measurement points on the control boards.

[nielsquake]

Made some extensions for the HV plugs using NST wire and some garden hose that I filled with wood glue around it to seal it completely



The wire was snipped of so short that I had to angle grind some of the aluminum plug housing off completely to expose part of the wire with the insulation intact.
Tested the plugs by connecting them to my flyback and a microwave transformer to see if it would arc through and it seemed to work fine.
I'm getting my 1kw max output ZVS driver tomorrow so I'll probably do some short tests shortly to see if it works the way I think it does.

[nielsquake]

Oh and I just called the supplier I was talking about and he claimed that this unit has the inverters installed in a separate container from this transformer box. If this is the case I assume this might make it easier to drive right? as the ZVS should adjust the frequency accordingly to the resonance or something like that and there isn't any hardware in front of the primary?
Maybe 2 pins of the 4 pin input just correspond to the filament transformer?
Also he told me this one was rated for 80kW so that is good to know!

BTW I now realize that you meant this system was driven by these IGBT inverters from an external source (I saw your video on that specific transformer you were pointing out and you showed the inverters inside the separate enclosure) I was just slightly confused but now it's a lot more clear to me how the internals are wired up. I just assumed that you meant the inverters were under oil with the flyback and that it was all part of this one unit so that is why I was confused on how to drive it...

[nielsquake]

Now that the glue is dried it looks pretty nice:

[nielsquake]

Hell yeaaa, it works!

This is 135W input from laptop charger but it looks like the output is just fine  

[nielsquake]

Test with a little bit more voltage. it seems to be less efficient then a TV flyback with this weak input power (arc is about half as long) but it makes me happy to see a nice arc comming from a machine like this

Oh and the primaries are not center-tapped in these kinds of transformers right? Since it runs fine with just these two inputs (the red and blue one)

[Mads Barnkob]

Oh and the primaries are not center-tapped in these kinds of transformers right? Since it runs fine with just these two inputs (the red and blue one)

Congratulations on getting it to run! I have 2 x-ray transformers that still sit untested in my workshop

I have only seen x-ray transformers with single or split primary coils (driven by each their being either negative or positive), but not any center tapped.

The secondary winding is however center tapped, so you should be able to locate the center bridge and you can use that to measure the secondary output current with a correct size shunt resistor or maybe even a clamp on meter