I need a replacement part

[Hextejas]

for this xformer and I have been unable to find something similar for less than $20.00.
It goes into a desk lamp.When I had an electrician friend show me how to determine that it was faulty, he said something that made no sense to me. (not a surprise).
Anyhow, he asked me for a new bulb and he said something about it being both AC and DC. ?
Apparently I had bought the right bulbs by accident.
That dual voltages was a mystery to me and I think it might have something to do with the proper xformer.

many thanks

[BeBuLamar]

What dual voltage? The transformer is simply a 120VAC to 12VAC step down transformer. The light bulb should be 12V. I don't know if you can get the tranformer for less than $20. Prices have been increased quite a bit but the transformer should be easy to find a replacement.

[reboots]

Here are a couple of inexpensive 12V electronic power supplies which might work, if you're sure the transformer is bad.

https://www.ebay.com/itm/276316962657
https://www.amazon.com/dp/B015HLH4SM/

If your lamp uses an incandescent bulb, it would work on either AC or DC. I think your friend was telling you that with the right bulb, it wouldn't matter whether you used an AC or DC 12V power supply.