Macintosh polymer recap & ESR considerations

[PeteS in CA]

Re: Macintosh polymer recap & ESR considerations

Looks like my memory was largely incorrect regarding the PM, PJ, and PW series:

PS Series, 2200uF, 6.3V, 12.5x20, .075 ohm impedance, 1250 mA ripple current

PM Series, 2200uF, 6.3V, 10x31.5, .043 ohm impedance, 1470 mA ripple current

PJ Series, 2200uF, 6.3V, 10x31.5, .066 ohm impedance, 1470 mA ripple current

PW Series, 2200uF, 6.3V, 10x25, .045 ohm impedance, 1440 mA ripple current
PW Series, 2200uF, 6.3V, 12.5x20, .038 ohm impedance, 1655 mA ripple current

PA Series, 2200uF, 6.3V, 10x20, .035 ohm impedance, 1490 mA ripple current
PA Series, 2200uF, 6.3V, 10x25, .033 ohm impedance, 1680 mA ripple current

HE Series, 2200uF, 6.3V, 10x25, .042 ohm impedance, 1650 mA ripple current

The PS series might still be closer to the original parts, with PJ next. But PM, PW, and HE are similar. If the caps being replaced are close to hot parts, I'd lean toward PW over HE because of how the different electrolyte types respond to heat.

[JDW.]

Re: Macintosh polymer recap & ESR considerations

Thank you for the advice.

I am unable to find the PM or PS or PL series Nichicon capacitors your suggest on Mouser for the sizes I need. But this Nichicon chart shows obsolete and replacement capacitor series. The PL series you mention (replaced by PM) is called "extremely low impedance" by Nichicon. So I'm a bit confused by your advice. If you compare the Tan Delta (Dissipation Factor, which is ESR/Xc) of the PM series you suggested to the PJ series & PW series that worries you, they are the same. Indeed, they are all classified as low impedance capacitors.

If you scroll back to my previous post and click the links in my uppermost "All standard electrolytics" list you will see I selected Nichicon UHE and UBT series, along side the Panasonic FR series. I also picked Wurth for the biggest cap because that was the only 150uF 400V cap available from Mouser with the correct lead spacing. These are low ESR capacitors (especially so because I picked caps in that list with higher voltage ratings than the stock capacitors, which tends to lower ESR), but those are not polymer caps and therefore ESR is nowhere near as low (nothing low like 40m-ohm). So I will probably go with that "standard electrolytic" list, unless you or someone else can say why that too would not be a good idea. A schematic of that PSU would help, but for the life of me, I can't find one. So all we have are those photos.

By the way, I recapped the larger SONY power supply that is used in the Macintosh SE and SE/30 with success using standard electrolytic capacitors, some of which are low ESR, including the Nichicon UHE series as shown in my RECAPPING List here. (There is a link to a schematic there too.) But I must admit that I did not spend time on circuit analysis and consider the "best ESR." Choosing the "best caps" in terms of ESR and long life is what I am pondering now for my forthcoming HD20SC recapping job, and indeed that is why I posted in this forum.

[PeteS in CA]

Re: Macintosh polymer recap & ESR considerations

The power supply in your pictures appears to have bee built in 1988, based on the date code marked on the Fujitsu MB3579, which looks like a PWM similar to (or a clone of) a TL494.

That was right around the time when Nichicon introduced its PL series; the current PM series is the RoHS-compliant version of the PL series. Sony was a very good power supply vendor, and might actually have used an equivalent of that brand new series. Or maybe the equivalent of the previous generation.

So you could probably use either the PS or PL series parts from Nichicon. Like stj, I think you will have stability problems if you try polymer caps; I would be nervous about trying PJ or PW series (LXV or LXZ from NCC) parts.

[stj]

Re: Macintosh polymer recap & ESR considerations

polymer in an ancient psu?
let us know if it works - but i expect issues.

[JDW.]

Re: Macintosh polymer recap & ESR considerations

Here are my photos of the HD20SC SONY PSU from 1988, which uses mostly Rubycon caps. (I'll talk about my CRT yoke board with Sprague caps in a later post.) Again, I am trying to determine if I should use extremely low ESR polymer caps as replacements, for reasons I've already mentioned.

I put together 2 capacitor replacement lists from parts in-stock at Mouser, as follows (click P/N links to visit individual parts pages on Mouser):

HD20SC PSU REPLACEMENT CAPS - All standard electrolytics

C226: 22uF 35V, D=5.2mm, Leads=5mm -- (Mouser: UHE1H220MDD1TD)
C202: 47uF 25V, D=5.2mm, Leads=5mm -- (Mouser: EEU-FR1E470B)
C222: 47uF 25V, D=5.2mm, Leads=5mm -- (same as C202)
C109: 150uF 400V, H=32mm, D=25.8mm, Leads=10mm -- (Mouser: 860021383023)
C110: 4.7uF 350V H=32mm, D=12.8mm, Leads=5mm -- (Mouser: UPM2G4R7MHD)
C210: 330uF 16V, D=8.1mm, Leads=5mm -- (Mouser: EEU-FR1E331B)
C215: 470uF 10V, D=8.1mm, Leads=5mm -- (Mouser: EEU-FR1E471YB)
C213: 22uF 100V, D=10.2mm, Leads=5mm -- (Mouser: UBT2A220MPD1TD)
C214: 2200uF 10V, D=12.7mm, Leads=5mm -- (Mouser: UHE1C222MHD1TO)
C209: 2200uF 16V, D=12.7mm, H=30mm, Leads=5mm -- (same as C214)

CR-35 daughter card:

C181: 100uF 10V, D=5.2mm, Hmax=12.5mm, Leads=5mm -- (Mouser: EEU-FR1E101B)
C182: 100uF 10V, D=5.2mm, Hmax=12.5mm, Leads=5mm -- (same as C181)


HD20SC PSU REPLACEMENT CAPS - All polymer caps except C109, C110 & C214/209

C226: 22uF 35V, D=5.2mm, Leads=5mm -- (Mouser: A759BQ226M1HAAE075)
C202: 47uF 25V, D=5.2mm, Leads=5mm -- (Mouser: A750EK476M1EAAE040)
C222: 47uF 25V, D=5.2mm, Leads=5mm -- (same as C202)
C109: 150uF 400V, H=32mm, D=25.8mm, Leads=10mm -- (Mouser: 860021383023)
C110: 4.7uF 350V H=32mm, D=12.8mm, Leads=5mm -- (Mouser: UPM2G4R7MHD)
C210: 330uF 16V, D=8.1mm, Leads=5mm -- (Mouser: RL81C331MDN1KX)
C215: 470uF 10V, D=8.1mm, Leads=5mm -- (Mouser: RNE1C471MDN1)
C213: 22uF 100V, D=10.2mm, Leads=5mm -- (Mouser: A759MS226M2AAAE045)
C214: 2200uF 10V, D=12.7mm, Leads=5mm -- (Mouser: UHE1C222MHD1TO)
C209: 2200uF 16V, D=12.7mm, H=30mm, Leads=5mm -- (same as C214)

CR-35 daughter card:

C181: 100uF 10V, D=5.2mm, Hmax=12.5mm, Leads=5mm -- (Mouser: RNS1A101MDN1KX)
C182: 100uF 10V, D=5.2mm, Hmax=12.5mm, Leads=5mm -- (same as C181)

[PeteS in CA]

Re: Macintosh polymer recap & ESR considerations

Sprague's bits and pieces got bought by multiple companies. Nippon Chemi-Con bought some of Sprague, too.

That said, Sprague 672D series was equivalent to NCC's RX series and, I think, Nichicon's old PA series. Sprague's 673D and 674D series were equivalent to NCC's RZ series and, I think, Nichicon's old PB series.

I do not think NCC or Nichicon had equivalents to Sprague's 676D and 677D series; NCC's RZA series was higher ESR than 676D/677D. However, I don't think Apple would have used 676D/677D, and probably not 673D/674D.

The meanings of "Low Impedance" (the more modern term) and "Low ESR" have evolved over time. The ESR of NCC RX series would be laughed at here, but in the late 70s and early 80s they WERE Low ESR.

I started working with power supplies at Boschert in 1980 and have been in power electronics ever since. So I've used the series mentioned above and am sure of the equivalencies. If Nichicon's PS series is still available, that is probably the low impedance series closest to the 672D, RX, and old PA series, but it probably is much lower in impedance than those old series parts.

[stj]

Re: Macintosh polymer recap & ESR considerations

well list the series of caps your interested in.

[JDW.]

Re: Macintosh polymer recap & ESR considerations

here is a datasheet collection.
http://www.paullinebarger.net/DS/

Thank you!

Alas! No Sprague (non in the Vishay folder either). :-(

The Rubycon datasheets at that link all seem to be rather new -- nothing from the 1980's that I can see. Ditto for the Nichicon datasheets.

Hmmm....

[stj]

Re: Macintosh polymer recap & ESR considerations

in the 80's you got low esr by putting 3-6 (or more) caps in parallel with ceramics,

here is a datasheet collection.
http://www.paullinebarger.net/DS/

[JDW.]

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.