Author Topic: Solid aluminium capacitor - replacement  (Read 291 times)

0 Members and 1 Guest are viewing this topic.

Offline HendoNZ

  • Contributor
  • Posts: 5
  • Country: nz
Solid aluminium capacitor - replacement
« on: January 09, 2021, 03:54:12 am »
Hi all,
I'm re-caping an old reel to reel (1970s)  and I've come across a 3.3uf 25v cap. In the documentation its listed as a solid aluminium capacitor. Is there a modem day equivalent to this type, or can it be replaced with a normal cap?


Offline bob91343

  • Super Contributor
  • ***
  • Posts: 1401
  • Country: us
Re: Solid aluminium capacitor - replacement
« Reply #1 on: January 09, 2021, 06:35:17 am »
Any capacitor with similar ratings will probably be fine.  Try it and see.

Online Ian.M

  • Super Contributor
  • ***
  • Posts: 9484
Re: Solid aluminium capacitor - replacement
« Reply #2 on: January 09, 2021, 09:12:20 am »
Wikipedia has 1983 as the date the earliest commercially available solid Aluminum electrolytic capacitors became available:
Are you sure the equipment is 1970s?

If it is a solid Aluminum electrolytic, and its capacitance is in tolerance, and its its ESR and leakage current still low, I'd simply put it back.  Otherwise if you can't find a physically compatible modern equivalent, replacement with a solid Tantalum capacitor with at least 50% higher voltage rating should be acceptable.  However we'd need to see that section of the circuit from the schematic (with supply rail voltages marked) to be certain, as Tantalum caps  are extremely intolerant of high current transients and reverse voltage and have a nasty tendency to catch fire when subjected to either and connected across low impedance supply rails.
« Last Edit: January 09, 2021, 09:17:19 am by Ian.M »

Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo