Polycom formerly Obihai Obi202 VoIP Adapter - Capacitor Replacement Recommendations

[Almighty1]

Greetings everyone:

I have a Polycom formerly Obihai Obi202 VoIP Adapter which has the following 2 capacitors:
1 x ChengX 100uF 25V 0.25"Wx0.3125"H
1 x YST 10uF 50V 0.1875"Wx0.4375"H

What are suitable replacements that are long life and rated 105C or higher? Am I correct that the uF has to match but the voltage can be the same or higher? Are there any advantages and disadvantages if it's higher than the original voltage?

Thanks!

[PeteS in CA]

Re: Polycom formerly Obihai Obi202 VoIP Adapter - Capacitor Replacement Recommendatio

It depends on how those caps are used. A power supply output capacitor is stressed more than a general purpose decoupling capacitor. If these are general purpose parts, then 105C general purpose parts from a good vendor should do fine. OTOH, if these are output capacitors, then you should, ideally, match the impedance of the original parts or maybe a bit better.

Higher voltage parts would be OK, though case size and impedance might limit choices. Matching the capacitance would probably be best.

[Almighty1]

Re: Polycom formerly Obihai Obi202 VoIP Adapter - Capacitor Replacement Recommendatio

Thanks for your reply. Any specific candidates you would recommend as I have no idea how those are used and when using Digikey and Mouser, there are a lot of choices, not even sure how each series ranks in each brand even for the Japanese brands. Not sure what the impedance on the original parts are either. The power supply itself is actually a plug-in wall adapter as the input is already 12VDC at the point the power adapter connects to the unit.
Someone did a teardown of the device here:
https://www.youtube.com/watch?v=ovMrUPe2CJE

[lti]

Re: Polycom formerly Obihai Obi202 VoIP Adapter - Capacitor Replacement Recommendatio

Those cheap caps are usually marked "low ESR" if they are anything other than general purpose. There are some areas where an ESR too low can cause problems (like the output of some LDO regulators), but 10uF caps don't have a low enough ESR for that.

For the 10uF cap, Rubycon YXF or Kemet ESL are cheap enough low ESR caps (although the Kemet caps are really just Teapo and not much cheaper than the Rubycon). I don't see any 100uF 25V caps that small on Digikey, but it looks like there is room for a taller cap. If it's on the 12VDC input, general purpose caps like Rubycon PX would work there.

[Almighty1]

Re: Polycom formerly Obihai Obi202 VoIP Adapter - Capacitor Replacement Recommendatio

@Iti - Thanks for your input. Where is it usually marked "low ESR", is it actually on the capacitor physically itself since it's hard to find the spec sheets as it is hard to even know what series they came from. It seems like if I am only buying 2 caps, the cost of shipping will probably be high so might as well spend a little more to get what I can as long as it's a small amount more. If there isn't enough room for the height as it seems to have 0.5" of height space and some space remaining without touching the top lid, couldn't one just do what they do in some circuit boards by basically having the cap mounted at a angle above the board?

[lti]

Re: Polycom formerly Obihai Obi202 VoIP Adapter - Capacitor Replacement Recommendatio

Sometimes the cheap caps have "Low ESR" printed directly on them. You could lay them on their side, but normal 100uF 25V caps should be the same height as the 10uF you have.

It does seem weird to only buy two caps.

[Almighty1]

Re: Polycom formerly Obihai Obi202 VoIP Adapter - Capacitor Replacement Recommendatio

I basically measured it with a metal ruler from the top of the board but the capacitors are not seated all the way so it's leveled and a bit angled. I'm compiling a list now of the different Japanese caps available and see what I can come up with.

[Almighty1]

Re: Polycom formerly Obihai Obi202 VoIP Adapter - Capacitor Replacement Recommendatio

After some research, it seems my options are:

For the 100uF 25V 0.25"/6.35mm Wx0.3125"/7.9375mm H:
None exist with the 6.35mm diameter W so increasing the height to 11mm
1) Nichicon UPW1E101MED 25V Tolerance: -+20%, 5000Hrs@105C, Ripple Current 290mA@100kHz, Impedance 0.25@20C 100kHz/0.50@-10C 100kHz $0.37
https://www.digikey.com/en/products/...E101MED/589561
2) Nichicon UKT1E101MED for Audio 25V Tolerance: -+20%, 1000Hrs@105C, Ripple Current 140mA@120Hz $0.51
https://www.digikey.com/en/products/...101MED/1964347
3) Nichicon UKT1V101MED for Audio 35V Tolerance: -+20%, 1000Hrs@105C, Ripple Current 150mA@120Hz $0.50
https://www.digikey.com/en/products/...101MED/1964359
4) Panasonic EEU-EB1E101SB 25V Tolerance: -+20%, 7000Hrs@105C, Ripple Current 95mA@120Hz $0.46
https://www.mouser.com/ProductDetail...VBytGsAw%3D%3D
5) Rubycon 25PX100MEFC5X11 25V Tolerance: -+20%, 1000Hrs@105C, Ripple Current 135mA@120Hz $0.28
https://www.mouser.com/ProductDetail...RI7MsQ3w%3D%3D
6) Rubycon 25YXH100MEFC6.3X11 25V Tolerance: -+20%, 5000Hrs@105C, Ripple Current 340mA@100kHz, Impedance 0.22@20C 100kHz/0.87@-10C 100kHz $0.42
https://www.mouser.com/ProductDetail...2FB6HyMQ%3D%3D
7) Rubycon 25YXJ100M5X11 25V Tolerance: -+20%, 5000Hrs@105C, Ripple Current 250mA@100kHz, Impedance 0.40@20C 100kHz/1.2@-10C 100kHz $0.28
https://www.mouser.com/ProductDetail...nYG2jZ8w%3D%3D
8) United Chemi-Con EKMQ250ELL101ME11D 25V Tolerance: -+20%, 1000Hrs@105C, Ripple Current 125mA@120Hz $0.39
https://www.mouser.com/ProductDetail...1blgcztA%3D%3D
9) United Chemi-Con EKZE250ELL101MF11D 25V Tolerance: -+20%, 2000Hrs@105C, Ripple Current 405mA@100kHz, Impedance 0.13@20C 100kHz/0.41@-10C 100kHz $0.49
https://www.digikey.com/en/products/...01MF11D/756189

For the 10uF 50V 0.1875"/4.7625mm Wx0.4375"/11.1125mm H:
1) Nichicon UKL1H100KDDANA 50V Tolerance: -+10%, 1000Hrs@105C, Ripple Current 70mA@120Hz $0.36
https://www.digikey.com/en/products/...KDDANA/2428102
2) Nichicon UPW1H100MDD 50V Tolerance: -+20%, 2000Hrs@105C, Ripple Current 120mA@100kHz, Impedance 1.40@20C 100kHz/2.80@-10C 100kHz $0.27
https://www.digikey.com/en/products/...H100MDD/589631
3) Nichicon UKT1H100MDD for Audio 50V Tolerance: -+20%, 1000Hrs@105C, Ripple Current 46mA@120Hz $0.36
https://www.digikey.com/en/products/...100MDD/1964373
4) Panasonic ECA-1HHG100B 50V Tolerance: -+20%, 1000Hrs@105C, Ripple Current 39mA@120Hz $0.34
) https://www.mouser.com/ProductDetail...QCzM6gng%3D%3D
5) Panasonic EEU-EB1H100S 50V Tolerance: -+20%, 5000Hrs@105C, Ripple Current 27mA@120Hz $0.44
https://www.mouser.com/ProductDetail...FClLsIIw%3D%3D
6) Panasonic EEU-HD1H100 50V Tolerance: -+20%, 1000Hrs@105C, Ripple Current 39mA@120Hz $0.52
https://www.mouser.com/ProductDetail...vZyc4FZQ%3D%3D
7) Rubycon 50ML10MEFC5X7 50V Tolerance: -+20%, 5000Hrs@105C, Ripple Current 30mA@120Hz $0.33
https://www.mouser.com/ProductDetail...0WLK51VQ%3D%3D
8) Rubycon 50PX10MEFC5X11 50V Tolerance: -+20%, 1000Hrs@105C, Ripple Current 47mA@120Hz $0.35
https://www.mouser.com/ProductDetail...4rP2PvpQ%3D%3D

[Almighty1]

Re: Polycom formerly Obihai Obi202 VoIP Adapter - Capacitor Replacement Recommendatio

Looks like I can fit up to 15mm in height as that is the tallest component being the RJ-11/RJ-45 jacks which still leaves a bit of room.

Also found some Panasonic FR series candidates:
For the 100uF 25V 0.25"/6.35mm Wx0.3125"/7.9375mm H:
Panasonic EEU-FR1V101 35VDC Tolerance: -+20%, 6000Hrs@105C, Ripple Current 950mA@100kHz, Impedance 0.056@20C 100kHz $0.72
https://www.mouser.com/ProductDetail...G7%252Bg%3D%3D
This is 8mm Wx11.5mm H - there is space for it just that it's going to be outside the printed circle on the board.

For the 10uF 50V 0.1875"/4.7625mm Wx0.4375"/11.1125mm H:
Panasonic EEU-FR1H100 50V Tolerance: -+20%, 5000Hrs@105C, Ripple Current 250mA@100kHz, Impedance 0.340@20C 100kHz $0.39
https://www.mouser.com/ProductDetail...dNSgjToQ%3D%3D
This is 5mm Wx11.0mm H which is still within the printed circle on the board.

I noticed something, it seems some list the Ripple Current at 120Hz while some lists it at 120kHz which means it's not really a valid comparison, how does one convert the number the other to know how they really compare?

[Almighty1]

Re: Polycom formerly Obihai Obi202 VoIP Adapter - Capacitor Replacement Recommendatio

Just a update, I went with the following as replacements:

For the Chengx® 100uF 25V 0.25"/6.35mm Wx0.3125"/7.9375mm H:
Panasonic FR EEU-FR1V101 35VDC Tolerance: -+20%, 6000Hrs@105C, Ripple Current 950mA@100kHz, Impedance 0.056@20C 100kHz

For the YST 10uF 50V 0.1875"/4.7625mm Wx0.4375"/11.1125mm H:
Panasonic FR EEU-FR1H100 50V Tolerance: -+20%, 5000Hrs@105C, Ripple Current 250mA@100kHz, Impedance 0.340@20C 100kHz

Photos:

(Before)



Capacitors - original on the left, replacement on the right next to it:


(After)

[sam_sam_sam]

Re: Polycom formerly Obihai Obi202 VoIP Adapter - Capacitor Replacement Recommendatio

One less device in the landfill good work on recapping the device