I gather, so far, that there is a variac component to this equipment. And that it was manufactured by the MRC Manufacturing Corporation (a Subsidiary of Materials Research Corporation), which once stood in Orangeburg, NY.

Please take a gander through the attached photos and let me know what you think. Any sort of description better than 'MRC Variac+' would be greatly useful/appreciated.

MRC Unknown1

MRC Unknown2

MRC Unknown6

MRC Unknown7

MRC Unknown8

MRC Unknown9

MRC Unknown10

MRC Unknown11

  • \$\begingroup\$ A variac is an autotransformer with variable number of turns. The insulation of the winding is re3moved, and a brush, perhaps carbon/copper composite, slides across the bare section to change the ratio of turns, and therefore the voltage out. \$\endgroup\$ – DrMoishe Pippik Oct 28 at 2:54
  • \$\begingroup\$ Jacob, are you asking us to help you identify this for the purposes of improving your knowledge of its provenances and therefore its value, and/or market targeting, for the purposes of re-sale? Or am I misunderstanding the purpose here? \$\endgroup\$ – jonk Oct 28 at 3:20
  • \$\begingroup\$ @jonk, education value above all. I know not whether I would ever sell this or not. It's merely a part of my extended collection, which has gone inadequately identified for far too long. Appreciate all of your help (best community that I could possibly turn to)! \$\endgroup\$ – Jacob Irwin Oct 28 at 3:24
  • \$\begingroup\$ @JacobIrwin Education is a broad word. It includes everything from just knowing the name of something to knowing how it functions in its intimate details. I won't press. Thanks very much for your reply. \$\endgroup\$ – jonk Oct 28 at 3:33

Probably a low voltage/high current AC source.

The Variac is relatively low VA compared to the range of the CT/ammeter, and there appears to be a transformer or inductor with a high-current winding in addition to the metering current transformer.

It could be a source for measuring material characteristics of highly conductive samples, or a source for resistance welding, but the company name would tend to imply the former.

Measure the voltage at the terminal block vs. Variac setting. You might also want to determine if the output is isolated from the mains.

Edit: Based on the Wikipedia page, I'm going to make a wild guess that this is a high current source used for vacuum evaporation. The 'boat' used in the vacuum chamber would look something like this:

enter image description here

The aluminum part at the bottom with the copper rods going through it is a high-current vacuum feedthrough. Looks like the conductors are liquid cooled via internal channels.

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It could be the low voltage, high current (100 A maximum), variable AC source for a heater in a high temperature, controlled atmosphere, X-ray diffractometer attachment.

The following (in italics) are extracts from pages 8 & 9 of the source - 'High temperature, controlled atmosphere, X-ray Diffractometer Attachment': https://www.osti.gov/servlets/purl/4574509

'With 0.010-in. platinum a temperature of approximately 1400'C at 80 A is obtained with the MRC power supply.'

'The AC current is fed to the heater by the MRC power supply, which consists of a powerstat, a step-down transformer, and an ammeter.'

The 'powerstat' would be the variac feeding the primary winding of the step-down transformer with its secondary winding outputting high current via the ammeter CT.

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  • \$\begingroup\$ I see the 'MRC Model X-86-N Diffractometer Attachment' referenced on p. 6 in the document, i.e., via the link you provided: osti.gov/servlets/purl/4574509. I had to login through my university's e-library portal to access additional relevant materials and a visual of the closest MRC product that I could find was an image/photo of] the 'MRC Cryogenic Diffractometer Attachment, Model X-86-NC' (note: the extra 'C'; I took a screenshot: pasteboard.co/JxIvzUO.png). As for Model X-86-N, I suppose the jury is still out. \$\endgroup\$ – Jacob Irwin Oct 28 at 9:58
  • \$\begingroup\$ @Jacob Irwin, p. 6 states that the chamber for the high temperature diffractometer is a modified version of the cryogenic (very cold) diffractometer chamber. The screenshot shows only the cryogenic diffractometer units. p. 6 also states - 'Two additional units essential to the operation of the diffractometer attachment are an electrical power supply, also purchased from MRC, and Leeds and Northrup components for controlling the specimen temperature'. It is clear from that and the extracts from pages 8 and 9, that the unit you possess is the one used with the high temperature diffractometer. \$\endgroup\$ – vu2nan Oct 28 at 11:16
  • \$\begingroup\$ @Jacob Irwin, MRC X-86-N3 is the model number of the high temperature diffractometer attachment. \$\endgroup\$ – vu2nan Oct 28 at 14:28

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