Help needed to identify components on an ARC-TIC PCB

[633Squadron]

I am working to repair the Kilmak Fantom inverter welder and have identified out most of the major components on the circuit board; however, I need some help identifying two components that have me stumped and the RS Components search facility drew a blank about them.
The first is marked 'TA-316100' on the side and is a two-pin black ceramic package, approx. 20mm square x 10mm height with a hole in the centre. It's labelled TRF4 on the PCB. There are no other markings on the package. This might be a current inductor, as there is a failry hefty wire that passes through the hole in the centre and is soldered to tbe board.

The second is marked 'ULUS C28 3x500uH SM0204570' (or possibly 'SM6204570', it's faded and a bit smudged) and is an 8-pin black ceramic package with pins numbers embossed into the top. The package is 20mm x 18mm x 10mm height, but the top of the part is 'stepped' in by about 1.5mm on two sides, parallel to pins 1 and 8 (the pin numbering runs in a circle, 1 to 8 anti-clockwise). There is also a logo, possibly an arrowhead pointing to the right inside a circle. There is no discernible marking on the PCB to indicate what this is.
Any ideas as to what these might be, based on these descriptions?

 

[rtbcomp]

'ULUS C28 3x500uH SM0204570' I'm guessing 3 500 µH inductors in a package

TA-316100:

http://www.datasheets360.com/part/detail/ta-316100/3549107852478976743/ although the pin count doesn't match your description. "TRF4" would suggest a transformer.
http://www.utkcomponent.com/en/prodotti_scheda.php?prod=7

 

[633Squadron]

The pinout for TA-316100 is two pins on the data sheet and does match what I described; that's exactly what I needed - thanks!

I'll keep digging on the other part, although you could be right that this is another inductor, possibly a current-limiting type.

 

[rtbcomp]

The pinout for TA-316100 is two pins on the data sheet and does match what I described; that's exactly what I needed - thanks!

..........

I see that now, I only looked at the 1st diagram in the datasheet, I also assumed the discrete components were embedded in the package. It looks as though there should be a wire threaded through the hole in the device.

 

[633Squadron]

There is a wire going through it and it's a fairly substantial one.

I'm gradually working out what all of the major components are and what voltages/currents they are likely to take, before I start probing with the meter. Picking bits of vapourised voltmeter out of my face isn't top of my bucket list, so I am takine a cautious approach as 'Here be Dragons' in terms of voltages and currents for the unwary.

Our site sparks reckons the 'ULUS C28 3x500uH SM0204570' is some sort of inductor transformer, although I've not found a match for it yet. ULUS appear to be a Turkish electronics parts manufacturer. That makes sense given the origin of the equipment.

 

[the snooper]

the first is a current sensing transformer hence the cable running through the centre, like you would use a clamp meter

 

[Wedg1e]

The 3x500uH unit could be a coupling transformer as used to fire thyristors etc.

 

[633Squadron]

A friend of mine thought it might be a delay line transformer, to switch the MOSFETS on or off as the current setting dictates. That would make sense if it's firing the gates of the MOSFETS.