Does anyone have access to old electrolytic capacitor datasheets from the 1980's and 1990's?
I am trying to determine what the typical ESR values were for various capacitors of that era. It's sometimes good to know what the original ESR of the stock capacitors were in order to properly recap vintage computing equipment. This is especially useful in cases where a schematic of the board to be recapped is not available.
Currently on my recap list are the Macintosh 512k (1985) , the 3rd party PSU inside a special Mac 512k that powers a GCC HyperDrive HDD, various Macintosh SE/30 boards (1989), Apple HD20SC Sony PSU (power supply of this external HDD enclosure), and a Mac SE/30 CRT Yoke board (Micron Xceed Grayscale adapter board - schematic).
I've done complete SE/30 recap jobs (motherboard, analog board, SONY PSU) using standard aluminum electrolytic caps (mostly Nichicon or Panasonic brand) with success, but I'm wondering where solid polymer could be even better. Solid Polymer Electrolytic capacitors have a very long life (at 65°C and lower) and extremely low ESR compared to even modern aluminum electrolytics, but there may be cases where the ESR is too low. That's my concern and the basis for this post.
Being able to lookup the data on the stock capacitors (or similarly rated caps of that era) would go a long way toward helping determine if a regular aluminum electrolytic capacitor should be chosen over say an OSCON.
If no one has vintage data sheets, then may I ask how many of you have recapped vintage Macs with OSCON or similar polymer electrolytics? (Not all caps can be replaced with polymer caps, I know.)
I would appreciate hearing your thoughts.
Thank you.
P.S. I posted about this on the 68kMLA but due to the lack of replies there I found this forum and thought I'd give it a go. There are a lot of savvy people over there, just not about specific capacitor choices.
I am trying to determine what the typical ESR values were for various capacitors of that era. It's sometimes good to know what the original ESR of the stock capacitors were in order to properly recap vintage computing equipment. This is especially useful in cases where a schematic of the board to be recapped is not available.
Currently on my recap list are the Macintosh 512k (1985) , the 3rd party PSU inside a special Mac 512k that powers a GCC HyperDrive HDD, various Macintosh SE/30 boards (1989), Apple HD20SC Sony PSU (power supply of this external HDD enclosure), and a Mac SE/30 CRT Yoke board (Micron Xceed Grayscale adapter board - schematic).
I've done complete SE/30 recap jobs (motherboard, analog board, SONY PSU) using standard aluminum electrolytic caps (mostly Nichicon or Panasonic brand) with success, but I'm wondering where solid polymer could be even better. Solid Polymer Electrolytic capacitors have a very long life (at 65°C and lower) and extremely low ESR compared to even modern aluminum electrolytics, but there may be cases where the ESR is too low. That's my concern and the basis for this post.
Being able to lookup the data on the stock capacitors (or similarly rated caps of that era) would go a long way toward helping determine if a regular aluminum electrolytic capacitor should be chosen over say an OSCON.
If no one has vintage data sheets, then may I ask how many of you have recapped vintage Macs with OSCON or similar polymer electrolytics? (Not all caps can be replaced with polymer caps, I know.)
I would appreciate hearing your thoughts.
Thank you.
P.S. I posted about this on the 68kMLA but due to the lack of replies there I found this forum and thought I'd give it a go. There are a lot of savvy people over there, just not about specific capacitor choices.
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