| Electronics > Beginners |
| Test capacitors without an ESR meter? |
| << < (3/6) > >> |
| bitseeker:
--- Quote from: cbmeeks on September 21, 2016, 08:14:38 pm --- --- Quote from: JacquesBBB on September 21, 2016, 07:51:57 pm ---Is there a special reason why you do not want to use an ESR meter ? --- End quote --- I *want* to use one, just haven't talked myself into buying one yet. :-) I know I need one. But, this is a hobby for me so I have to choose my purchases wisely. Plus, I would have thought a $10 ESR meter is about as good as a $10 multi-meter. Probably better than nothing, I suppose. --- End quote --- A $10 multimeter can measure a correct voltage, just as a $1000 one can. Of course, they're different in various ways, but it's much better having a $10 DMM than not having any. Similarly, you can make good use of a $10-20 component tester (and it's good for more than just ESR). |
| dannyf:
--- Quote ---Like something that would estimate a cap being within 10% of specs or 80% of specs, --- End quote --- No meter could do that, as it wouldn't know the spec of your capacitor. and many times, esr is not spec'd. even when it is spec'd, a capacitor may exhibit different esr under different test conditions. Much simpler would be for a meter to measure the esr of a capacitor under a given condition, and you make a judgment whether that is good or bad. |
| JacquesBBB:
The difference with a 10$ multimetrr is that this one is open source, open hardware And fully documented http://www.avrtester.tode.cz/upload/ttester_en.pdf#page1 I would recommend to get one where the IC is easily replacable/programmable As a bad move can fry the device. Through hole with IC on a socket is my preference. Although they are many with graphic screen, i am not sure they are any better than 2 lines Lcd display. |
| singapol:
--- Quote from: cbmeeks on September 21, 2016, 08:14:38 pm --- --- Quote from: JacquesBBB on September 21, 2016, 07:51:57 pm ---Is there a special reason why you do not want to use an ESR meter ? --- End quote --- I *want* to use one, just haven't talked myself into buying one yet. :-) I know I need one. But, this is a hobby for me so I have to choose my purchases wisely. Plus, I would have thought a $10 ESR meter is about as good as a $10 multi-meter. Probably better than nothing, I suppose. --- End quote --- To be honest in this hobby it's no fun if you don't have "meter" or instruments to measure electrical properties. ;D You don't learn much! Since your budget is tight even a $10 all in one meter IS better than nothing. With respect to ESR , it is always good and essential to measure for repair and restoration but the final call is with you. The essential thing is knowledge about electrolytic capacitors, how it works and how it is manufactured will help you decide to replace a cap with regards to functionality of the circuit and the environment it is used in for reliability and lifespan. The thing about E caps is it packs a lot of capacitance in a relatively small package compared to film caps which use the separation or gap between foil/electrode and a plastic insulator but an E cap uses a chemical solution called an electrolyte to work much like electrolysis so the insulation layer is only chemical in nature and is only molecules thick if you remember your physics class theory. This is called forming by the cap industry and you need to charge it with electricity or layman's term "powering" it in a piece of equipment. The often given advice to power your equipment regularly has a basis in this fact. Industry determination of useful lifespan is by theory and practical testing and interpolation of results at the full rated voltage and temperature. As you know when there is a current flowing heat is produced and it is this heat effect that eventually cause the majority of E cap failures. There are learned ways of calculation from the links below. In my honest opinion and also based on my own experience, this knowledge helps you decide or make your decision to replace and scrap a cap or not. ;) Also do note in consumer electronics the equipment is not used often unlike in a workplace eg. everyday so caps generally last longer. there is one link from an expert that claims a 50 year lifespan. :-// Ultimately it's your call so the more info you have about caps the better it is. http://www.powerguru.org/electrolytic-capacitor-lifetime-estimation/ http://www.powerguru.org/influence-of-the-operating-voltage-in-the-useful-life/ http://www.powerguru.org/influence-of-the-operating-voltage-in-the-useful-life/ http://www.rubycon.co.jp/en/products/alumi/pdf/Life.pdf http://www.dfrsolutions.com/wp-content/uploads/2014/06/A-New-Method-for-Testing-Electrolytic-Capacitors-to-Compare-Life-Expectancy.pdf http://bgavinsound.com/Reference/Electronics/Capacitor%20Replacement/Capacitor%20Life%20Expectancy.pdf 50 yrs. lifespan? https://enphase.com/sites/default/files/Electrolytic_Capacitor_Expert_Report.pdf |
| w2aew:
Here's a video I did showing how to measure ESR (only one measure of capacitor "goodness") with a scope and a function generator (square wave generator) |
| Navigation |
| Message Index |
| Next page |
| Previous page |