I need to replace my doorbell transformer in order for my Ring video doorbell to consistently have sufficient power. After searching long and hard I finally located the transformer, which appears to be EXTREMELY old (house was built in 1890). After pulling the cover off, it seems to be filled with some sort of black material (hard) so I can’t see any wiring or even begin to think of how to replace it. Any suggestions would be very helpful. I’ve attached a couple pictures for reference.

Thanks. Max!

Inside transformer:


Outside transformer:

  • it's filled with insulation, a process now called being "potted". It's likely an oil-based material like resin or tar. It's still just a plain old 12v transformer though. what is your specific question? – dandavis Nov 15 '18 at 21:24
  • The best way to find information on this device is to copy the text stamped on the cover into an online search engine. – A. I. Breveleri Nov 15 '18 at 21:51
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    @dandavis make that an answer and I will up vote+ wow that is an old K&T era transformer. I am surprised that they did not replace it when the Romex wire was updated. Carefully remove and sell it on EBay. I used to maintain some old K&T Victorians that the owners wanted to keep original and this stuff is hard to find especially in good condition. I have warmed the ceramic on dead ones and stashed a new transformer in the case in the past. For the right person it could be worth your time to sell it and install a new one. – Ed Beal Nov 15 '18 at 21:52
  • @dandavis Thanks Dan. Filled with insulation would make sense. My specific question is how do I go about replacing the transformer? My doorbell loses power constantly, which I assume is due to an outdated/under-powered transformer. Everything I've seen online makes it seem like replacing the transformer should be an easy task, but I can't find anything that looks close to the way mine is currently set up. The insulation threw me for a loop because I'm not sure how I go about replacing the transformer. – max Nov 16 '18 at 22:55
  • the same 4 wires will connect to a new transformer, though I would redo the input side. you can just stack a new transformer on top of the old one, run AC to the input, then chop off the old outputs and wire them into the new output side. in short, the details of your old one don't exactly matter too much. – dandavis Nov 17 '18 at 14:04

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