Introducing CapRep

[TheSolarShed]

Good day, all

I would like to take this opportunity to (nervously) introduce a project on which I have been working: CapRep (Open to suggestions for a better name).

What is CapRep?
Finding a suitable replacement capacitor involves looking up the specifications of the existing caps and then (for me, at least) trawling through datasheets of "good caps" to find a suitable match. For this reason, I created CapRep (Capacitor Replacer). CapRep contains a database of quality brands and series of caps that it searches against your criteria.

How to use CapRep
Using the form, input the capacitance, voltage, and ripple capacity of the cap to be replaced. Click "Find replacements" and CapRep will search its database and return a list of caps that match, or better are than, your search criteria. Input additional (optional) information and receive more specific results.

The results CapRep returns

• Capacitance - Equal to search criterion.
• Voltage - Equal to or greater than search criterion.
• Ripple - Equal to or greater than search criterion.
• ESR - ±20% around search criterion (if value input).
• Diameter - Equal to or less than search criterion (if value input).
• Height - Equal to or less than search criterion (if value input).

What next?
There are still many features I'd like to implement, the most important currently being:

• Layout and aesthetic tweaks
• Expand database (currently 430 caps, but growing weekly)
• Advanced search options

Feedback
I'm interested to hear what the community thinks of my little project: Do you find it useful, words of encouragement, words of hate . Find a bug? Report it. Ideas to improve it? I'm all ears.

Regards,
TheSolarShed

[momaka]

Re: Introducing CapRep

Very neat project! I'm actually quite surprised that no one on this forum has commented on this yet.

A while back, we had a thread in the VIP where a member (Uranium235 if I remember correctly) was assembling a large capacitor database. I don't think it ever got finished, but that database was huge. I think if that was ever combined with your project, it could be a very nifty capacitor replacement tool.

As far as your project, it appears to work well. However, I tried entering the data off of a 10V 2200 uF Fuhjyyu TM, but the search results suggested Nichicon HZ, HM, Sanyo WG, and Rubycon ZLJ as replacements. In reality, neither of these are suitable for PSU use - which is most likely where that Fuhjyyu is to be found (usually older Antec PSU and Channel Well). I'm not sure if those results are due to a capacitor database that is too small, but a better suggestion would have been United Chemicon KY.

Also, I tried entering the ESR of the cap, but that made the search results show nothing. It looks to me like the search engine is looking for a specific ESR rather than a "closest" value. I think that's all really that might be needed to make it better.
For example, when I specified a 6.3V 2200 uF 10 mm dia. cap with 2150 mA of ripple (I took the specs from a Chemicon KZE cap here), the first result that appears should be Chemicon KZE followed by close equivalents. In this case, your search engine did show Nichicon HD and Panasonic FR, which are perfectly equivalent caps... but they were at the bottom of the list while Nichicon HZ, HN, and HM were at the top. Again, in a situation where you are replacing caps in a power supply, this could cause a problem.

So just because a cap has lower ripple current or higher ESR doesn't necessarily mean it's completely unsuitable. Let's say you need to replace a cap in a PSU and it has, say, 1000 mA of ripple current. But let's say the size of that cap is critical (i.e. you can't fit a bigger cap in there and a smaller cap doesn't exist). If there are only two caps from all of the good brands that have the same size dimensions - one with 900 mA of ripple, and the other with 4000 mA of ripple, then the 4000 mA cap may not necessarily be the better choice if its ESR is too low and the circuit is very sensitive to low ESR. While this scenario is completely fictional, it's not impossible. So I think a tolerance for the ripple current would also be a good idea. Now, since we don't want overstressed caps, perhaps it would also be a good idea to highlight in red the caps that don't quite "meet" the specs of the originals and indicate that they are just "reasonably" close.

Anyways, sorry to yap like this. What you have is a very very nice project and I think it only needs a bit of tweaking to make it perfect. I think your project combined with a huge capacitor database could make a universal cap replacement tool.

[TheSolarShed]

Re: Introducing CapRep

Hi momaka,

I'm actually quite surprised that no one on this forum has commented on this yet.

Thank you very much for your reply! I too am surprised it took as long as it did.

I'm not sure if those results are due to a capacitor database that is too small...

Indeed, the database unfortunately is still very small (601 caps as of this post) so there won't be very good matches for all situations. My main focus now is expanding the database with the goal to add an entire series every day (of the smaller series) as well as some from the larger series.

So I think a tolerance for the ripple current would also be a good idea.

I had also thought about adding a range to the ripple criterion. Something like values >= (input - x%). Perhaps also set a limit on the upper limit ie. (input - 10%) >= values <= (input + 50%). This will be a setting under the future Advanced Search. For now, I shall add a tolerance that includes ripple current 10% below the search criterion.

It looks to me like the search engine is looking for a specific ESR rather than a "closest" value.

Currently, it searches for ESR values that are 20% above and below the search criterion. Adjusting this range will be a setting under the future Advanced Search.

...your search engine did show Nichicon HD and Panasonic FR, which are perfectly equivalent caps... but they were at the bottom of the list while Nichicon HZ, HN, and HM were at the top.

The results are ordered by ESR then by ripple; it's the easiest way to sort them in the SQL statement for now. With a large enough database, the most suitable caps should be centered in the list. However, I imagine it would be better to place the best match at the top and have the rest in decending order. Another "problem" is that it will return all results, even if there are 50 of them, which is unnecessary. So I also plan to limit the number of results to a certain number.

...perhaps it would also be a good idea to highlight in red the caps that don't quite "meet" the specs of the originals and indicate that they are just "reasonably" close.

Already on the to-do list.

Anyways, sorry to yap like this.

No worries at all, I greatly appreciate the detailed descriptions. I wouldn't classify the results as "noob-proof" yet; they still require evaluation and thought.

Regards,
TheSolarShed

[TheSolarShed]

CapRep has moved!

If anyone cares... CapRep has moved!

I have decided to move CapRep to a paid-hosting service for a few reasons. The new URL is shedhead-projects.co.za/caprep.

Also, having recently completed my Masters degree, I hope to have a little more time for working on the site and adding more capacitors to the database.

Regards,
TheSolarShed

[momaka]

Re: Introducing CapRep

Cool. Good to see this project is still alive. Keeps us updated how it goes. I think once the fews stuff that I mentioned in my previous post are worked out, this might become a very handy tool for people who don't know where to start when it comes to finding capacitor replacements.

Also, congrats on your Masters degree! Mind sharing what it is?

[Behemot]

Re: Introducing CapRep

You have PM Shed. Regarding that, I may even help you with the DB buildup as I see opportunity in this…

Besides that, I think than also adding a second table to the results with "similar" caps may be usefull. Like caps having close capacity (it may not be a problem to swap 1500uF cap for 1200uF and using 1800uF is even better mostly) or close physical dimensions. Especially in displays, where you have to replace 2-3 generations old caps, the new ones have higher capacity in same package.

[TheSolarShed]

Re: Introducing CapRep

[QUOTE=momaka]Cool. Good to see this project is still alive. Keeps us updated how it goes. I think once the fews stuff that I mentioned in my previous post are worked out, this might become a very handy tool for people who don't know where to start when it comes to finding capacitor replacements./QUOTE]

Hi, momaka

Whenever I have a board to recap, I use my own website. If it returns no results, I find caps that match and then add that series so there is still much to do and I hope it proves to be invaluable to everyone. I haven't been very contributive to this community, yet I have always wanted to give back. How else better than with my very own hobby?

Also, congrats on your Masters degree! Mind sharing what it is?

Thank you! It was a control systems topic (electrical and electronic engineering though I prefer the electronics side of things). I had to design a control system for a small-scale (~10kW) wind turbine that uses a reluctance synchronous machine as the generator.

You have PM Shed. Regarding that, I may even help you with the DB buildup as I see opportunity in this…

Besides that, I think than also adding a second table to the results with "similar" caps may be usefull. Like caps having close capacity (it may not be a problem to swap 1500uF cap for 1200uF and using 1800uF is even better mostly) or close physical dimensions. Especially in displays, where you have to replace 2-3 generations old caps, the new ones have higher capacity in same package.

Hi, Behemot

I have replied to your PM. I am very excited to work with a well-established member of the community such as yourself! I have so many ideas for the site, but hope that I have the ability to implement them all. I am a novice at web design (hence the bland site design), but it's amazing what one can do with only a text editor and CSS . It works and I'm proud of it.

Aaaaaand there goes my mind, racing with ideas. Better write them down! Also, how about a sticky for this thread? No?

Regards,
TheSolarShed

[Behemot]

Re: Introducing CapRep

It would be good to add lifetime at temperature for each particular capacitor and also links to full datasheet. You can find most datasheets here http://www.paullinebarger.net/DS/ I also have part of that for my own use in one big RAR archive so I have in by hand all the time. Will send ya link to my server.

[Behemot]

Re: Introducing CapRep

404 Not Found
File not found.
micro_httpd

What's the status?

[goontron]

Re: Introducing CapRep

Micro httpd? WTF? Is he running this thig off a router?

[Behemot]

Re: Introducing CapRep

Still nothing?

[Behemot]

Re: Introducing CapRep

I guess we may call this project dead. Pity.

[LDSisHere]

Re: Introducing CapRep

This website is working for me. This could be a very useful tool if it continues to be developed.

I think one of the reasons this thread has not attracted much attention is due to it being in the same sub-form as the new introductions so it has gotten overlooked by many of the site veterans.

[shovenose]

Re: Introducing CapRep

The website in the OP is not the right one the right link is in post #4

[kc8adu]

Re: Introducing CapRep

nice!
how did i miss this?

[Behemot]

Re: Introducing CapRep

The website in the OP is not the right one the right link is in post #4

Good catch! I totally missed that after some time. May be worth editing the first post than

The question now is, is TheSolarShed still working on it? I am prepared for deeper cooperation beneficial to both of us, but well, it all depends on the fact whether he is going to work on it or not.

[Topcat]

Re: Introducing CapRep

Good catch! I totally missed that after some time. May be worth editing the first post than

The question now is, is TheSolarShed still working on it? I am prepared for deeper cooperation beneficial to both of us, but well, it all depends on the fact whether he is going to work on it or not.

I edited the original post to reflect the new link. Nifty program, I hope you keep at it. When its complete, I'd be willing to implement it into BCN, of course full credit back to you.

[awilhite]

Re: Introducing CapRep

If you open-sourced the code, I would be willing to progress the project.