OK people.
We all know the story.
Many people in the hobby suggest replacing all caps in about all electronics we come across in our hobby. With good reasons of course. Electrolytic capacitors (often shortened as caps, or as we say in Holland Elko's) _CAN_ dry out over time and loose (partly) their function.
Yes, even I was always replacing caps like nuts on everything I came across. But as soon as my first cap-kits from a certain well known supplier arrived, I got some doubts.
The delivered Xicon caps felt extremely light and looked cheap. Of course, just like with everything, people will vary in opinion, but I've searched the internet, and generally Xicon is not considered as being a top brand cap maker.
Still, I have done several PCB's (like the one's in my SW cockpit) and others. Yes they work OK (mostly), but it didn't feel right somehow to take out the Nichicons (yes old, but one of the top cap brands) and replace them with the Xicons...
Also note that cap producers build various lines of products, each with their "target" use. Some are simply better than others.
So, the alternative was to shop at RSonline for good brand caps. Panasonic sounded trusty enough, and also Rubycon and Nichicon were available. I steered clear from the RS (own) brand for the same reasons as not wanting the Xicons.
Now.....I had made a list of caps that I was going to need to replace for my Asterock. Pretty soon (also because of minimum quantities you must order, like 5) I had reached an amount of almost 50 Euro's. Yes I selected all good quality brands and 105 degr. versions, but still that's a considerable amount of money.
Another factor. I've got a number of game PCB's, PSU's, and even monitors (f.i. the very old Sanyo in my Nintendo cab) that are still running the old caps and they simply look GREAT.
I've also done some measuring in the past around an original Atari Big Blue and there was virtually 0 ripple voltage over it, indicating it was still running fine....
Now...of course lots of these caps are 30 years old. So.....what I wanted is a quick and simple way to KNOW if I should replace a cap, or not.
A general DVM (or multi-meter as wel call it) is useless if it already HAS a capacitance tester. What this does is simply measure the capacitance, and even IF it gives (about) a good indication, that's not really that important and not an indication if an electrolytic capacitor is still OK. (Check capacitance values, they already have a 20% margin in their value from the factory !).
Now what we DO want to know is the ESR, or in other words the Serial resistance of the cap. Now you cannot measure this with a normal Ohms meter, because it's a cap....
Some time ago, there was a smart bloke from Australia (Bob Parker) who invented a cheap ESR meter that was affordable for everyone, but still very useful.
His name is Bob Parker. IIRC the meter was published by a magazine and thus a kit to be build. Later all kind of companies produced them in different ways:
http://members.ozemail.com.au/~bobpar/esrmeter.htmThe principal is that a 100 kHz frequency is sent through the cap, and this signal is analyzed to know the ESR value.
Anyway, two versions of this meters were pretty interesting. One is from Russia:
http://www.radiodevices.ru/esr/esr4.htmThis one has some very good specs and I really like some features like the test socket on the device itself. It's also quite cheap.
However, they have had delivery problems of parts fort the past couple of months and I don't really want to wait any longer.
So.....I ordered this one:
http://www.peakelec.co.uk/acatalog/jz_esr70.html
This is readily available. There are even some Dutch distributors but one only delivers to companies and the other was simply more expensive than ordering directly at the manufacturer....
This one also has excellent specs and features and it looks very professionally built. One of the best features is that it discharges caps should they have any load left. This makes it not necessary to discharge them all before measuring which saves a lot of time.
Anyway, as soon as I receive it I will do some measuring on new and old caps and publish some results here.
I think this is a good investment that will earn itself back in a very short time.
