0
\$\begingroup\$

I have a transformer from a 1953 jukebox that seems to be increasing in voltage over time. When I first got it, it was outputting 32V. A week later it seemed steady at 38V, then 45V. Now I just measured it and it's at 50V.

I see no visible signs of burning or excessive heat and I've not seen or smelled any smoke.

It is supposed to be a 115V => 32V (approx) transformer.

What is going on? Do I need to throw this thing out?

enter image description here

\$\endgroup\$
6
  • 1
    \$\begingroup\$ I guess that could happen if the primary windings were shorting out one-by-one. I don't know how likely that is. Are you testing the transformer by itself or is there a circuit connected to it? \$\endgroup\$
    – user253751
    Jul 23, 2020 at 23:00
  • 4
    \$\begingroup\$ Check the battery in your multimeter. Seems like it might be going flat. \$\endgroup\$
    – brhans
    Jul 23, 2020 at 23:05
  • 2
    \$\begingroup\$ Could it be old/weakening battery in the DMM causing incorrect measurements? As a test, if you measure a AA battery and instead of 1.5V it reads 2.3V, that's the problem. \$\endgroup\$
    – MarkU
    Jul 23, 2020 at 23:05
  • 2
    \$\begingroup\$ Welcome. Are you tracking the AC input voltage as well? This can and will vary with time. \$\endgroup\$
    – user105652
    Jul 23, 2020 at 23:05
  • 1
    \$\begingroup\$ What kind of DMM are you using to make these measurements? Some very low quality DMMs are not rated for measuring 110VACrms line voltage safely. Peak 110VAC voltage is more like 170V peak. And 48V DC is considered the highest "safe" DC voltage. \$\endgroup\$
    – MarkU
    Jul 23, 2020 at 23:08

1 Answer 1

Reset to default
0
\$\begingroup\$

@brhans was correct above - once I replaced my batteries I started getting stable readings out of this transformer. Thanks everyone

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.