Products > Test Equipment
Best Electrolytic Capacitor to Recap an Oscilloscope?
tautech:
--- Quote from: helius on April 30, 2020, 04:51:09 am ---
--- Quote from: tautech on April 29, 2020, 11:43:35 pm ---I try to break circuits into types, say if SMPS, caps will need to be low ESR and it's wise to use higher heat ratings also.
Linear PSU's OTOH are less demanding of cap performance and low ESR here can be a mistake as initial cap charge at turn ON can exceed rectifier surge ratings if insufficient headroom wasn't factored into the original design.
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Another situation where low ESR is a mistake is at the power input of a low-voltage device with a remote power supply. The power lead inductance can cause harmful ringing without the C+R acting as snubber.
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Quite so, and you sometimes see this remote bulk capacitance on a long power rail some distance from the PSU. The caps are usually not large, say a few 100 uF at most and technically they provide rail decoupling yet the obligatory 0.1uF decoupling ceramics on each IC are used too.
Mp3:
--- Quote from: james_s on April 30, 2020, 05:31:06 am ---
--- Quote from: Mp3 on April 30, 2020, 03:52:22 am ---
--- Quote from: Miti on April 29, 2020, 11:02:47 am ---In the power supply I always use Nichicon PW series, they never failed me. I’ve also used them to recap the main board of a Tektronix 2445B. In general I only use Nichicon and Rubycon in all my important repairs.
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Yup, Nichicon PW is great stuff. Lately, I've been pretty much ONLY using United Chemi-Con though. I still use Nichicon PW as my first preference after EKY or KWB series. Been really happy with them.
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I've found Panasonic to be good as well.
Really most of the reputable brands are fine. I avoid the very cheapest stuff and I look at the rated lifespan.
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Good point, Panasonic is great for making lots of high reliability options in just about every size you need, but I usually pick them only when I have to since they tend to sound like garbage in audio applications. If you're not working on something that needs to be heard, Panasonic is totally fine. Totally subjective, though, but I know others who work on audio stuff share my sentiments
Every time i need to buy caps and UCC or Nichicon doesn't have the cap i need at the lifespan/heat tolerance i want, i go for Panasonic every time.
W3KW:
I found this video very helpful: https://youtu.be/lrXCVg6T-ek -a Tek 2235 scope.
The comments section had a shopping cart for Digikey. Merely click on the link, find suitable replacement caps for out of stock parts (there were maybe 4) which digikey makes super easy to do, and purchase. Wow. Super helpful. If someone has a shopping list put together for the 465, 465B, 2246, or 2465B, please share it on this thread. The author of the above YouTube video even labeled the part numbers in the list for super convenient inventory and part location. Thank you, sir!
If I need to put parts orders together on my own for those scopes, I’ll try to post the shopping cart link in a thread on the eevblog.
Thanks in advance if you’ve got one and can share it!
Wes
W3KW
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