I got mine since 2013 . Still going . The small aligator are due to low inductance wires . On high frequency counts allot . Comparing de5000 against a proper tool Bode 100 Vector Network Analyzer for hobiest the de5000 does just fine .
it is a very nice meter. It even beeps at you after a couple minutes if you forget to turn it of. The longer leads will influence the capacitance measurement, especially the small value's. Could you please make a comparison of much lower value capacitors, something like in the pF and 1nF; 10nF.
Dissipation factor! A very important measurement..... This measurement is referring to how much DC current is passing through the capacitor! In a perfect world, a capacitor should only pass DC current until it reaches operating voltage of the circuit it's in or its maximum rated voltage printed on the side of the capacitor. There should not be any measurable DC current across the capacitors, unfortunately we don't live in a perfect world and capacitors will leak DC current, some will be worse than others, you want this figure to be as low as possible! Decoupling capacitors with a high dissipation factor will act as a load on the power supply, causing the power supply to work harder and hotter while pulling down the voltage rails for the rest of the circuit. In the case of coupling capacitors, like for example between audio stages, a capacitor that is passing DC current onto the next device in line which is usually a transistor will bias up or down depending on the actual transistor used and cause a failure which sometimes ends up being a cascading failure which takes out many components.... Most people just check for ESR, while bad ESR can cause issues, a capacitor with bad ESR shouldn't cause a failure! It's the capacitors with bad dissipation or as known by Drain factor that is responsible for delivering component failures.... I prefer to test capacitors by putting them in series with a μA meter to measure for DC current leakage, slowly bringing up the voltage to what the capacitors are rated for. Sometimes I see leakage slowly creeping in but after a short period of time sitting with the same voltage applied, the current drops and I can continue doing this until rated voltage. Note that this only applies to new capacitors! The longer a capacitor sits in your parts bin, the more it will dissipate and for longer.... They do stabilise but if the capacitor has a critical role in a circuit and you can going to use something that you have had in stock for ages, it's most likely gone into what I like to call a comma, it's going to need some time to wake up! Applying full rated voltage after sitting around unused for years is the equivalent to someone giving you the biggest slap just as you have gone into deep sleep! Not good! You too will probably blow up just like a capacitor does LoL.... It's advised on the Panasonic capacitor datasheet to reform their capacitors if they have been sitting around for a year or more.... Never reform used capacitors to use in new circuits! While if you suspect that a device has been sitting around unused for an extended period of time, before applying full rated voltage, plug the device under test into a wattmeter and a Variac and slowly begin to bring up the voltage in jumps of 5 or 10V at a time, allow the device to rest after each jump with the voltage constantly applied while keeping an eye on the wattmeter for any drastic changes, if you see a wattage increase after a jump but it slowly goes down and settles, this is a clear indication that the capacitors are either slowly waking up or they are nearing their service life expectancy.... After reaching the full operating voltage of the device, another test should be completed on another day or if possible a week later, if the device under test has returned to the same behaviour, the capacitors are bad and will need to be replaced! If not, then all is well and the capacitors have returned to provide a good service life.... For testing capacitors for DC current leakage, I use my Variac which has a full bridge rectifier that also has a resistor and a switch so that I can bleed off the charge on the capacitor under test while at the same time the bleed off resistor can be taken out of the test circuit so that it doesn't interfere with the results, an analogue μA meter and shunt to see what the capacitor is doing, and that's it! I can dial in almost all voltages that I come across.... This test procedure should only be done by competent persons! A fully charged capacitor isn't something to be reckoned with! I would advise to construct a test jig with a clear cover hinged over the capacitor on a base, I'm currently working on an idea that includes a switch that is activated when the clear lid is opened which will short the capacitor to a bleed off resistor just in case this test jig ends up with someone who could forget to flip a switch to discharge the capacitor under test and find out the hard way! Other than that, I find that it's a cheap and good way to both test capacitors and wake up new old stock... Or test old one's to see if or how bad they are! I have many different types of purchased capacitor testers but I favour the simple and possibly dangerous way that I have described above.... Capacitors Ah! You can't live with them, you can't live without them! You just have to try and understand them as much as possible..... To make your life just a tad bit less painful 😖...
Very interesting information Peter! I don't often deal with high value capacitors, but I did build a discharge wand for the times I do. Clip one end to chassis ground and touch the cap terminals and the voltage is bled off through a resistor. So far so good!
@@offkafka A discharge wand is a must! A charged capacitor is a snake waiting to be stepped on! They bite! But the fact remains that the majority of people don't understand capacitors! I have seen people test a capacitor for ESR and the measurement returned to good result but.... I could see from all the way over here in Australia that the top of the capacitor had bulged and had leaked it's electrolyte..... The person in the video said that the capacitor is good! It's definitely not good! I also saw someone else test capacitors for capacity and the results showed that they somehow had more capacity that what they were rated for.... This is clearly a dry capacitor! The capacity of a capacitor should always be just below it's rating! No exceptions! If it's over, it's bad! If it's too low it's also bad! A good capacitor should have low AC series resistance! Should have high DC series resistance and it's capacity should be as close to its own rating but never over! Stick to this and you will always know if a capacitor is good or bad! I test capacitors by stepping up the voltage all the way to their rated voltage because a capacitor can test good a low voltages... By stepping up the voltage you get to see where the capacitor is beginning to go bad, you get to see how much life it has lost! You just don't get that sort of confirmation when using any of the capacitor testers made today! It's either good or bad and you don't know why! The old Heathkit high voltage capacitor testers were great at teaching by showing you how a capacitor works when I has begun to fail..... Mr Carlson's Lab channel has done videos using these old vacuum tube capacitor testers.... I highly recommend watching it if you haven't already....
