WARNING!!!
This transformer is being offered for experimentation, custom designed projects or even just to get the large gauge enamelled windings!
The new owner ABSOLUTELY MUST KNOW WHAT THEY ARE DOING, THERE ARE LETHAL VOLTAGES/CURRENTS AT THE PRIMARY
THIS TRANSFORMER HAS BEEN WOUND FOR USE ON 220V SYSTEMS (although it was actually in use here, more on that further down in the description) IT WOULD BE UNWISE AND UNSAFE TO POWER THIS TRANSFORMER USING OUR NOMINAL 240V AC DOMESTIC SUPPLY (which actually can go as high as 250V at times)
THERE ARE NO INDICATIONS IT HAS BEEN SAFETY CERTIFIED FOR USE IN AUSTRALIA
I firmly believe in sustainability, wherever possible I try to encourage the reuse or repurposing of electronic/electrical components in particular - a LOT of energy* went into manufacturing these transformers and to send them to landfill seems such a tradegy because we are slowly poisoning our environment with masses of eWaste.
*more information about this will be appearing on this website very soon
The asking price for these transformers is only intended to cover my time in creating this advertisement.
HISTORY:
This transformer was used here in Australia in old stage lighting equipment. I suspect the equipment was originally sourced from the Asian region, probably Singapore. Fans were installed inside the very large spots to keep everything cool.
The stage lighting equipment was dismantled due to obsolescence, not a fault
AC Stepdown Transformer
Country of manufacture is unknown
Former has MICHAEL stamped into it
Part # DT 8666 EI120b/53.7L-Si
Paper label attached on top indicates:
2x separate 110V windings (primaries)
1x 24V @ 13A
1x 14V @ 5A
Thats some pretty heafty current capabilitiy but the downside is the weight - this is VERY HEAVY @ 4Kg!
Dimensions: 120mm high x 120mm width x 100mm depth
Spade terminals for all connections
All terminals are numbered (see notes below about this numbering though)
COSMETIC CONDITION:
Not stored that well so the iron laminations show light rust to the top area, nothing too bad and certainly this will not affect operation of the transformer
All spade terminations are in great shape
Plastic former is not cracked or damaged
Core frame is a bolt on type and it is undamaged and with all bolts in place
TESTING:
Powered up via my Grundig Variac at 220V NOT 240V
Secondary voltages (open circuit) were measured as:
13 & 15 - 24.5V AC
18 & 20 - 10.5V AC
Windings are all enamelled wire
Don't forget that when AC 220V is first applied, there is considerable primary "inrush" current for a very brief period of time, this is completely normal but it can trip your household circuit breakers. There is nothing wrong with the transformer, it is the "nature of the beast" with these high current AC transformers.
Actually looks to be a pretty good solid build, windings look "tight"
Standard E core using iron laminations
If the transformer doesn't suit your purposes, as long as the former can be removed without much effort, there will be plenty of enamelled wire for another project and "scrap metal" the rest of the transformer via recycling.
WINDING DESIGNATION NOTES:
The paper label on the top indicates the windings as -
1 - 4 110V
7 - 10 110V
13 - 15 24V
18 - 20 14V
But looking at the primary terminations (top of the former), I find that I have 8 wires or 4 windings, not 2 as I expected.
DC resistance measurements:
Terminals 1 - 3 1.6 Ohm
Terminals 3 -4 O Ohm (my multimeter cannot read this low so I must assume it is a short)
Terminals 6 - 8 1.8 Ohm
Terminals 8 - 9 O Ohm (my multimeter cannot read this low so I must assume it is a short)
Terminals 4 & 6 are SHORTED TOGETHER (this must be the common point for the 2x 110V windings)
I applied the test 220V AC to terminals 1 & 8
The secondary terminations (lower part of the former) also have 8 wires but these seem more straightforward with 2 wires for each termination so it looks as though the secondaries are actually dual coils for each voltage.
THIS IS NOT AN AUTO TRANSFORMER - ELECTRICALLY THE PRIMARIES AND SECONDARIES ARE ELECTRICALLY ISOLATED. I ALSO MEGGER TESTED BETWEEN EACH "SIDE" OF THE TRANSFORMER AND TO THE LAMINATIONS - NO SIGNS OF INSULATION BREAKDOWN.
