XTRProf
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Pssst ! Got any spare capacitors ?
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Post by XTRProf on Oct 25, 2012 11:25:20 GMT
Well, do Panasonic, Muse, Silmic, cerafine, etc have 150uf or 180uf high voltage (450VDC) low ESR E-Caps? Looking to replace all the SMPSs with those due to age (> 3 years).
Form factor must be diameter < 22mm and height < 40mm (ideal 30mm).
Thanks.
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Post by gommer on Oct 25, 2012 12:03:33 GMT
Beware that some elco's might specifically be selected for relatively high ESR. Low ESR is not always a good thing in electronics, especially in SMPS's (think high peak currents, hence EMI problems).
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XTRProf
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Pssst ! Got any spare capacitors ?
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Post by XTRProf on Oct 25, 2012 13:53:06 GMT
Beware that some elco's might specifically be selected for relatively high ESR. Low ESR is not always a good thing in electronics, especially in SMPS's (think high peak currents, hence EMI problems). Er, the only high voltage ones are before the switching Mosfet are not switching at high ripple current but only at 100 or 120Hz after rectification. After secondary traffo, all switching at low voltage and much lower current already. Hope I'm right in the interpretation of how a SMPS works as I don't have a block SMPS diagram to analyse things but thru reverse engineering.
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Post by gommer on Oct 25, 2012 15:03:31 GMT
Chong,
Elco's have high parasitic inductance (wound structure). These are the reservoirs where the switching mosfets draw their current from. Switching mosfets have parasitic capacities, these *can* resonate with the parasitic inductance of the elco's. A high ESR elco reduces the Q factor of this resonant circuit and dampens the resonances.
All speculations, but not hypothetical.
Marc
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Deleted
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Post by Deleted on Oct 25, 2012 22:08:07 GMT
I have found that fitting a 100nF 630V capacitor in parallel with the main electro gives a worthwhile improvement in both video and audio, as does replacing the individual bridge rectifier diodes with BYV26C. I recently also did that with a Samsung BR player which had a faulty SMPS PSU that needed replacement. Alex
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XTRProf
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Pssst ! Got any spare capacitors ?
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Post by XTRProf on Oct 25, 2012 23:54:43 GMT
Chong, Elco's have high parasitic inductance (wound structure). These are the reservoirs where the switching mosfets draw their current from. Switching mosfets have parasitic capacities, these *can* resonate with the parasitic inductance of the elco's. A high ESR elco reduces the Q factor of this resonant circuit and dampens the resonances. All speculations, but not hypothetical. Marc Thanks Marc. That answers it. So "normal" ESR high voltage Elco it will be. I saw a Rubycon and Panasonic one that almost meet my form factor. Anyway, low ESR type like Silmic don't have anything higher than 100VDC and Cerafine high voltage type already out of production and sold out after some research. Muse? Still researching for the knowledge now. Mundorf don't need to research and sure have. Only the form factor may not meet dimensions needed. Even if it meets, I will not buy it as it's crazy to spend about SGD 20 to 40 for just one Elco and I have many to replace.
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XTRProf
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Pssst ! Got any spare capacitors ?
Posts: 5,689
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Post by XTRProf on Oct 26, 2012 0:02:51 GMT
I have found that fitting a 100nF 630V capacitor in parallel with the main electro gives a worthwhile improvement in both video and audio, as does replacing the individual bridge rectifier diodes with BYV26C. I recently also did that with a Samsung BR player which had a faulty SMPS PSU that needed replacement. Thanks Alex. Have that in mind too. Especially so now to go with the "higher" ESR high voltage Elco with Marc's technical advice. Now must find and buy a "bag" of 0.1 uf high voltage FKP Wima as have lots of 104 and 103 ceramic, which I don't personally like sonically and is not technical in nature, filters in the SMPSs to "upgrade" as well since I'm on it.
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Post by PinkFloyd on Oct 26, 2012 12:17:28 GMT
Well, do Panasonic, Muse, Silmic, cerafine, etc have 150uf or 180uf high voltage (450VDC) low ESR E-Caps? Looking to replace all the SMPSs with those due to age (> 3 years). Form factor must be diameter < 22mm and height < 40mm (ideal 30mm). Thanks. How many do you nee Chong? I have quite a few "random" high voltage caps kicking about, tell me exactly what you require. Mike.
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