sancon china caps

[spiros.p]

any experience from that brand (crap....emm) caps?found their site and see some 10000 - 20000 hours capacitors.

[AleXis6]

Re: sancon china caps

Suncon?
https://www.sunelec.co.jp/eng/company/history/

some sellers mention as SUNCON(SANYO)
i have a couple nominals

[spiros.p]

Re: sancon china caps

no it is sancon.propably crap cheap china.

[televizora]

Re: sancon china caps

Actually, according to my experience, SANCON are not that bad caps.
They are at the level of Teapo and are substantially better than Capxon, Suscon or Lelon.
Actually, everything is better than those 3 "brands".
I even used Sancons on motherboards or PSU-s. But I generally follow the rule - one magnitude greater voltage than the original cap.
If the original cap is 6.3V, I install 10V. If 10V - install 16V. If 16 - install 25V.

[spiros.p]

Re: sancon china caps

thanks for respond televizora.i found these on psu of cheap desolderind station.i have few left panasonic fr and replaced.i do the same when is posible to fit slight higher voltage than the older ones.

[goodpsusearch]

Re: sancon china caps

This rule is for those who don't know this forum and esr matching etc. Totally useless for us

[momaka]

Re: sancon china caps

This rule is for those who don't know this forum and esr matching etc. Totally useless for us

Well, increasing the voltage rating on a cap will net you higher ripple current and lower ESR (due to larger can size compared to a cap of the same brand and series, but with a lower voltage rating)... so it's not a bad technique, provided there is enough space on the board for doing this. In a situation where good quality caps are not available, then going one size up in voltage is better than nothing.

But in the end, you're right - if the ESR and ripple current is not matched or better than the original, then an increase of the voltage rating on the "wrong" cap type/series for the application may still yield a poor repair that doesn't last very long.

[AleXis6]

Re: sancon china caps

if the ESR and ripple current is not matched or better than the original, then an increase of the voltage rating on the "wrong" cap type/series for the application may still yield a poor repair that doesn't last very long.

could you explain how better ripple current will lead to the problem described above?

[momaka]

Re: sancon china caps

Sorry I didn't put enough details in that post.
By "better ESR and ripple current", I meant that the replacement cap should be rated to have same or lower ESR and same or higher ripple current rating.

The ripple current rating of a capacitor specifies the maximum "AC" the cap can take before overheating internally and getting damage... and usually that goes together with the endurance rating, specifying for how many hours you can run the cap at maximum ripple current (and usually max voltage and temperature) before non-reversible damage/degradation occurs.

So for example, if a switching circuit is producing about 1000 mA of ripple current and the cap is rated for 2000 mA of ripple current, then the cap will be able to handle the filtering of this circuit continuously without any issues.
Now let's say the same circuit with the same ripple current (1000 mA) is filtered by a cap that is only rated for 700 mA of ripple current. The cap *may* still be able to handle the filtering of this circuit continuously, but only if the cap is cooled well enough, such that the internal temperature of the cap does not exceed its rated temperature.
In both of the above cases, the two caps will work fine. However, the first case with the cap being rated for 2000 mA - that cap should last much longer, because the cap will run cooler internally, due to much lower ripple current presented by the circuit relative to what it can handle. On the other hand, the cap rated for 700 mA may not last very long because it would likely be running at a higher internal temperature. And for electrolytic capacitors, the lifetime of the capacitor approximately doubles for a drop in every 10 degrees Celsius (e.g. a 105C-rated cap with 2000 hour endurance rating should last at least 4000 hours at 95C, 8000 hours at 85C, and etc.)

As for ESR - this directly dictates how well the cap will be able to function as a "true" capacitor in the circuit, and therefore also directly affects the output ripple and noise of the power supply. Lower ESR = cap being closer to an "ideal" capacitor, and therefore filtering better and reducing the ripple and noise on the PSU output maximally. But this is only true to a point, because in real life circuits, extremely low ESR can also be a problem for PSU! This comes from the fact that any inductors in the PSU will form a resonant L-C circuit with the filtering capacitors, and that can cause "ringing" and oscillations on the PSU output, thus making it possible to end up with more ripple and noise (in addition to also upsetting the voltage feedback / monitoring circuitry.) And this is why polymer capacitors should not be used for recapping power supplies, unless the power supply was actually designed to be filtered by ultra-low ESR capacitors.
So when it comes to ESR, it's a good idea to keep the ESR of the replacement capacitors close to what the original caps were rated for.
In my experience, most power supplies will be OK with +/-50% change in the ESR (i.e. 1.5x lower or higher ESR.) But I don't suggest going past 5x higher ESR or 2-3x lower ESR - that's usually the tolerable limit for most power supplies.

[AleXis6]

Re: sancon china caps

Sorry I didn't put enough details in that post.)

thanks for the details.