Macintosh polymer recap & ESR considerations

[JDW.]

Re: Macintosh polymer recap & ESR considerations

Yes, that's what I have been saying. It's simply a lack of a full schematic that necessitated experimentation with various capacitors on my part to find the right one -- one that is still commonly found and I could recommend to others doing the same recap job.

[stj]

Re: Macintosh polymer recap & ESR considerations

yes, but there is a limit to how low the esr can go, usually related to the frequency of the circuit.

[JDW.]

Re: Macintosh polymer recap & ESR considerations

the dubilier cap had the lowest esr - that's why it had the best performance.

Consider well what I discussed before. The Nichicon capacitor I used originally had even lower ESR but the performance was worse, resulting in higher amplitude ESL spikes and a 1 kHz audible beep sound at power on. That needs to be taken into serious consideration. “Lowest ESR” does not guarantee the capacitor will be the best performer.

[stj]

Re: Macintosh polymer recap & ESR considerations

the dubilier cap had the lowest esr - that's why it had the best performance.

[JDW.]

Re: Macintosh polymer recap & ESR considerations

I purchased 3 capacitors from Mouser, and measured data using my DE-5000:

Illinois Capacitor 228CKS010M 2000hr@85°C:

ESR
@100Hz = 60mΩ
@120Hz = 50mΩ
@1000Hz = 43mΩ
@10,00Hz = 39mΩ
@100,00Hz = 42mΩ

DF@120Hz = 0.90
Capacitance = 2.11mF
Q@120Hz = 11.04
θ@120Hz = -84.7°

Panasonic EEU-EB1A222 10,000hr@105°C:

ESR
@100Hz = 90mΩ
@120Hz = 90mΩ
@1000Hz = 80mΩ
@10,00Hz = 74mΩ
@100,00Hz = 65mΩ

DF@120Hz = 0.138
Capacitance = 1.95mF
Q@120Hz = 7.2
θ@120Hz = -82.0°

Cornell Dubilier SEK222M010ST 2000hr@105°C:

ESR
@100Hz = 40mΩ
@120Hz = 40mΩ
@1000Hz = 31mΩ
@10,00Hz = 29mΩ
@100,00Hz = 27mΩ

DF@120Hz = 0.070
Capacitance = 2.06mF
Q@120Hz = 14.13
θ@120Hz = -85.8°

I soldered each of the above into my power supply and tested the resulting ripple and ESL spikes on my scope. None of these 3 caps caused the audible 1kHz beep sound at power-on, which was nice. Surprisingly, the highest ESL spikes came from the Panasonic, and the ripple was higher than any of the other capacitors (due to its ESR). It's rated for 10,000hrs but the ESL spikes were much higher than the other 2, so I won't be using it. Ripple and ESL spikes were almost the same for the Illinois and Cornell caps. I intend to use the Cornell due to its 2000hr@105°C rating versus 2000hr@85°C for the Illinois, and for its lower ESR and higher Q.

So the moral of this story is that its difficult to know which cap is best without testing. I had thought the Panasonic would win, but due to the higher ESL spikes it produced (which still somewhat baffles me), it was put out of the running.

Thanks to all who contributed to this thread.

[JDW.]

Re: Macintosh polymer recap & ESR considerations

well 13mm is wrong, the official size is 12.5mm,
if your trying to size-match there is nothing wrong with increasing the voltage to 16 or even 25v
have you seen this chart?

Yes, I had seen that chart when I visited the Rubycon website, but it does not mention the SH series from the 1980's, which isn't too big a surprise since I cannot find a mention on their website of any cap made prior to 1999. I also believe the USH series mentioned on page 3 of that PDF is not the same as the SH-series of the 1980's because USH is rated for 85°C whereas my stock cap in this power supply is rated 105°C. The presence or absence of the "U" is yet another differentiator that shows the two series are different.

13mm is not wrong within the context of what I wrote, but I see now I need to clarify. A capacitor with a Diameter of 13mm will physically fit into the space provided for that capacitor on the SONY PSU inside an Apple HD20SC power supply. That implies that a 12.5mm, 12.0mm and smaller capacitor diameter will also fit.

I fully understand there is ordinarily nothing wrong with choosing a higher voltage cap as a replacement, but in this case there is, insofar as the higher voltage caps tend to have lower ESR and Dissipation Factor, and on some switching power supplies, an ESR that is too low can cause phase shifts, oscillations and other undesirable behavior that negatively impact the stability of the said power supply. This info is often written into the data sheets of switching power supply controllers, many of which will specify very clearly how much ESR is required. In those cases, at least for modern switchers, it's common to see an ultra low ESR ceramic cap used in series with an SMD resistance of several hundred milliohms.

So in summary, I'm looking at capacitors that no only physically fit, but have sufficient ESR and/or Dissipation Factor to function in a stable way in this particular power supply.

[stj]

Re: Macintosh polymer recap & ESR considerations

well 13mm is wrong, the official size is 12.5mm,
if your trying to size-match there is nothing wrong with increasing the voltage to 16 or even 25v

have you seen this chart?

[JDW.]

Re: Macintosh polymer recap & ESR considerations

damn, well i think YXF is still sold.

Well, it's certainly not sold on Mouser. And since I usually share my recapping knowledge with others in the form of a replacement capacitor list, a readily available replacement capacitor that works well is critical.

Using my DE-5000 meter, I made the following measurements today spanning several minutes for each test to ensure the most accurate measurement, all at 120Hz because higher frequencies produced no results on my meter...

Stock Rubycon 2200uf 10V capacitor (SH-series, 105°C) (inside Sony PSU in Apple HD20SC):
• θ = -75°
• Q = 3.7
• R = 0.1Ω (only the tenths place was shown, so it could be 100, 150, etc.)
• D = 0.270

Nichicon 2200uf 16V capacitor (UHE1C222MHD1TO, 105°C):
• θ = -88.6°
• Q = 45
• R = 0.0Ω (only the tenths place was shown, so it could be 20mΩ, 60mΩ, etc.)
• D = 0.022

LCC 2200uf 25V capacitor (new but 16.5 years old, 85°C):
• θ = -87°
• Q = 20
• R = 0.0Ω (only the tenths place was shown, so it could be 20mΩ, 60mΩ, etc.)
• D = 0.049

Note that D is Dissipation Factor, aka tan δ, which is almost always shown in capacitor datasheets even when ESR is not.

After recapping, when I use the stock Rubycon cap, all is well and there is not beep/squeal shortly after I switch on power, and the peak-to-peak ripple on the scope shows as it did prior to recap -- about 50mVp-p. The ESL spikes are 100mVp-p max.

When I use the Nichicon cap, the ripple is about 70mWp-p and ESL spikes exceed 100mVp-p, and there is a beep/squeal sound shortly after I switch on power. I don't see a buzzer on this PSU, so I think the sound is coming from one of the two transformers, as per what my ear is telling me.

I then thought it best to try a new but very old cap I got when I bought my JAMECO electrolytic radial capacitor kit back in April 2003 (more than 16 years ago). That cap too is 2200uF but 25V and rating at only 85°C. It's marked LCC and I cannot find any data sheet for it. I doubt JAMECO had these kits in stock for more than 1 year, and I doubt the cap was made more than a year before the kits were assembled, so I would guess the age of the cap could be as old as 18 years. But again, it was new, never used, and always stored in a location where people are (i.e., no long term temperature extremes or excessive humidity). With this old LCC cap, there is no beep sound, and the scope measurements are exactly what I see with the stock Rubycon cap. This is interesting because if you look at my measurements above, the LCC still has much better test results than the Rubycon. The LCC's Dissipation Factor is more than twice the Nichicon's though, so perhaps that is the key here? Even so, it's still much lower than the 0.270 of the stock Rubycon.

In any case, the problem is easily solved for me by using either the stock cap or the LCC, but if I share a capacitor replacement list with others, the issue of that one cap is a sticking point. Sure, I could just advice using the stock cap, but what about cases where that cap is bad? And so I am trying to find a suitable replacement 2200uF 10V (or higher) cap that will physically fit (13mm x 26mm) and produce a stable output voltage. I think the beep after the switch-on is telling me of some instability, and the higher ripple voltage of the Nichicon replacement seems to bear that out.

Any further thoughts on this would be appreciated.

Thank you.

[stj]

Re: Macintosh polymer recap & ESR considerations

damn, well i think YXF is still sold.

[JDW.]

Re: Macintosh polymer recap & ESR considerations

i meant the YXA,B,F series

you obviously speak japanese - why not email Rubycon and ask them if they have old datasheets or compatability tables?

Here's the YXA datasheet and this page says it was last sold in 2012.

[stj]

Re: Macintosh polymer recap & ESR considerations

i meant the YXA,B,F series

you obviously speak japanese - why not email Rubycon and ask them if they have old datasheets or compatability tables?

[JDW.]

Re: Macintosh polymer recap & ESR considerations

well get the datasheet and see if the size you want even exists i suppose.

Where precisely do I find the datasheet for the Rubycon SH-series? That's really the foundation question upon which I built this discussion. I don't know who to ask or where to look.

Thanks.

[stj]

Re: Macintosh polymer recap & ESR considerations

well get the datasheet and see if the size you want even exists i suppose.

[JDW.]

Re: Macintosh polymer recap & ESR considerations

check YX range, YXA is highest esr, YXF is probably good for the job.

But where can I buy those? I am only finding YXG, YXH, and YXJ on Mouser, in the diameter and length required to fit onto my PCB.

[stj]

Re: Macintosh polymer recap & ESR considerations

check YX range, YXA is highest esr, YXF is probably good for the job.

[JDW.]

Re: Macintosh polymer recap & ESR considerations

I purchased all the caps for my Apple HS20SC external hard disk enclosure's power supply. It works OK with my replacement caps, but my replacement for the Rubycon SH-series 10V 2200uF capacitor is somewhat of a problem. My replacement is a Nichicon UHE1C222MHD1TO. The problem is the power supply makes a brief squeal (beep) sound when I switch on the power. It doesn't make that sound when I had the stock caps inside. And when I remove the Nichicon and put back the Rubycon (only that 1 cap, and all the rest my replacements), the beep goes away. Viewing the 5V rail on the scope shows a tad bit more noise (ripple) with my Nichicon replacement, but I believe the problem is that my replacement's ESR is too low, causing either a phase shift or unwanted oscillation.

I measured the Rubycon cap with my DE-5000 meter. At 120Hz it shows an ESR of 0.2-ohm. My replacement Nichicon is much less than 100-ohm -- so low the meter won't show the value at 120Hz.

Here's a photo of the stock Rubycon cap:



It measures D=13mm, H=26mm.

Do any of you have an old datasheet for the Rubycon SH-series? I can't Google up anything.

The problem is I am not finding any 10V 2200uF replacements on Mouser that would fit D=13.5mm(max), H=29mm(max) and have sufficiently high ESR. The ones that fit all have a quite low ESR specs. I don't have a schematic of this power supply, so a datasheet on the Rubycon would help a lot. Any ideas or suggestions would be appreciated.

Thank you.

[JDW.]

Re: Macintosh polymer recap & ESR considerations

I picked a random value/voltage to compare the various series, not for any other reason. Since I'm not being understood I'll drop out of the conversation rather than cause further confusion.

There is no confusion and I appreciate your comments to date. I simply look forward to hearing specific advice regarding the specific capacitors that I've been mentioning, rather than general advice. Since you have experience in power supply design, especially from that era, I assume you could provide such specific advice, right? I know it helps if we have a schematic, but unfortunately I can't find one.

[PeteS in CA]

Re: Macintosh polymer recap & ESR considerations

Thank you for the replies. You listed a variety of 2200uF caps rated for 6.3V. ...

I picked a random value/voltage to compare the various series, not for any other reason. Since I'm not being understood I'll drop out of the conversation rather than cause further confusion.

[JDW.]

Re: Macintosh polymer recap & ESR considerations

Thank you for the replies. You listed a variety of 2200uF caps rated for 6.3V. The stock cap of that same capacitance in the HD20SC power supply are these two:

C214: 2200uF 10V, D=12.7mm (Rubycon)
C209: 2200uF 16V, D=12.7mm (Rubycon)

Why SONY chose a 10V and 16V of the same capacitance value is a real mystery to me since there is vertical and horizontal space to fit 2pcs of the 16V capacitor. The ESR variance between the 10V and 16V cap would not big significant. For that reason I tentatively have put the Nichicon UHE1C222MHD1TO into my Mouser cart as a replacement for the 10V and 16V stock caps. From that linked datasheet you can see 12.5x25mm 2200uF 16V capacitor has an ESR@100kHz=0.028-ohm, which is an ESR difference of little to no significance in light of the fact the capacitors you listed are all well under 0.1-ohm, even for a 6.3V version (which again is not a voltage spec that pertains to the PSU in question).

And so, in light of the fact the HE-series Nichicon I have tentatively selected is a 10,000-hour rated capacitor, it seems the logical replacement choice here.

High capacitance value capacitors have low ESR as it is, and I don't believe those are being used in any kind of timing circuit in this PSU either (where ESR might matter). So I think the real question here pertains to the ESR of smaller capacitance caps in the HD20SC PSU.

More specifically, I am pondering ESR of the caps in my "All standard electrolytics" list that are between 22uF and 470uF in capacitance, rated at between 10V to 35V:

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)
C210: 330uF 16V, D=8.1mm, Leads=5mm -- (Mouser: EEU-FR1E331B)
C215: 470uF 10V, D=8.1mm, Leads=5mm -- (Mouser: EEU-FR1E471YB)
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)

It could be that some of these caps may be used in such a way that ESR matters. But again, without a schematic, it's difficult to know. Even so, as you can see from the list above, my tentative replacements are the Panasonic FR-series and Nichicon UHE-series mostly, which have a lower ESR than what the stock caps back in the 1980's had, yet not super-low (i.e., not less than 0.1-ohm) like polymer caps are. But my other big consideration here is capacitor life, and for that reason I have tentatively chosen replacements (in the above list) that are rated for 5000h and higher, all at 105°C.

[stj]

Re: Macintosh polymer recap & ESR considerations

PS/PJ look similar to rubycon YXJ series.