The underappreciate capacitor... - Page 1
Forum section: electronics / testgear

author: Fried Chicken
author_rank: Regular Contributor
timestamp: March 21, 2024, 04:06:15 pm
content: Right now I'm on thehunt for a bench multimeter, and it's a grave understatement to say there are options abound! Enter into the handheld space, and there are literal excel spreadsheets with hundreds of options. Pick whatever color you want!Another piece of test equipment that would be very useful for what I do is a good LCR meter. Mostly what I deal with is replacing capacitors on amplifier or power boards that have become wonky/annoying. It's helpful to know if the capacitor I've removed is, in fact, the source of whatever problem I might have, and testing an old vs new capacitor is a good way to do so...But so far as I can tell, there aren't many good options out there. New, used, vintage, chinese, American, you name it. I appreciate capacitance measurement is less straightforward than resistance, current, or voltage measurement, but they're just about the second most ubiquitous thing in electronics after resistors!Right now I have three ways of measuring capacitance, all of them not-ideal. I have a Hioki handheld multimeter that does a pretty damn good job but doesn't give any information beyond capacitance. I have a cheap-o chinese handheld thing that I don't trust at all, and then I have the $20 mTester guy that shoots way above its weight.... and gives an ESR! but its weight class is measured in grams so not a high bar there.Now I'm looking for a bench capacitance tester, and I'm quickly seeing prices for massively complex equipment shoot into $1k range for dubious used options.Whenever I go into deep rabbit holes researching equipment, I make notes to myself so that when I again enter the rabbit hole I have a good starting point. Here's what I have written:Code:Best LCR Meter:Notes:- Capacitors offer different response at different frequencies- an ideal capacitor has an ESR of 0Ω for an AC signal- LCR meters require competence and experience for the user- Hioki has terrible support for old devices, avoidBK Precision 879b- 880 has DCR and is 100khz vs 10khz for 879b- has ESR- poor build quality/reliabilityKeysight U1731C- U1732C has 10khZ vs 1kHZ for U1731C- https://www.keysight.com/us/en/catalog/key-34689/u1700-series-handheld-capacitance-lcr-meters.html- U1733C sold on eBay for $250, others <$200Cheap Option:- DE-5000Even Cheaper Option:- Amazon kit meter (Purchased)None of these are bench meters, the best option seems to be the Keysight!Those who have gone down this rabbit hole, what conclusions have you reached? Are there good vintage units available? Key things to look for? Maybe you just do the work yourself with a function generator and an ammeter to test capacitors? Surely this isn't a fast/elegant solution.Capacitors.... so underappreciated

author: TimFox
author_rank: Super Contributor
timestamp: March 21, 2024, 04:31:00 pm
content: Before retiring, I used good bench LCR meters for critical capacitor measurements, ending with the QuadTech (now IET) 1920.For our purposes, the variable bias voltage and AC drive voltage on the 1920 (also found on Agilent and other bench meters) were important, but you probably don't need that feature.After retirement, I obtained a DE-5000 and was quite impressed with its performance at a much lower price than the bench meters.My only complaint about the DE-5000 is that it cannot display X and R (or B and G): often, the reactance of the device under test (for example, a wirewound resistor) changes from inductive to capacitive from low frequency to high frequency, and the DE-5000's result is ambiguous.I have seen quibbles about the unit not retaining settings during power off, but for this low price I would not expect that feature.

author: Fried Chicken
author_rank: Regular Contributor
timestamp: March 21, 2024, 11:15:19 pm
content: The DE-5000 is looking a lot more tempting now. Seeing how the next step up is the U7133C and then it quickly gets into the absurd...I know there are so many threads on this and I appreciate the input

author: KungFuJosh
author_rank: Super Contributor
timestamp: March 22, 2024, 01:40:07 am
content: The DE5000 is a great meter.You should also look at the Shannon ST42 tweezers if tweezers would work for you.MY DE5000 is retired now, but I'd still refer to it if needed (I have the ST42 tweezers and an ST2832 bench meter).

author: TopQuark
author_rank: Frequent Contributor
timestamp: March 22, 2024, 04:00:06 am
content: I had a DE5000 but I find the form factor a bit unwieldy, especially with today's SMD components.I bought the LCR Research LCR PRO1 Plus tweezers and it has been excellent. Unless you have a massive through-hole cap or something like that, I think the tweezer form factor is the way to go. It does 100kHz which the ST42 does not, and the accuracy is great for the price.Recently I had the need to develop something akin to a transformer isolated milli-ohms meter that is impervious to series inductance changes (i.e. LCR meter), I tried the Pro1 with the transformer and it actually worked quite well. The absolute resistance shown in the photo does not mean much given all the extra resistances in series with the measurement, but the impressive part is the resistance measurement barely changes when I add a ferrite in series to the resistor DUT. Not a scientific measurement, but just a happy surprise discovery with the Pro1 Plus.

author: bdunham7
author_rank: Super Contributor
timestamp: March 22, 2024, 04:28:40 am
content: Quote from: Fried Chicken on March 21, 2024, 04:06:15 pmI concluded that you really want a 100kHz test frequency. On the budget end, the DER DE5000 seems to be a favorite. I don't have one but its reputation appears good. I have a BK 886 that I think is excellent, it has variable test voltages that go as low as 50mV, which is nice for in circuit testing. The replacement model, the BK 880 seems good and does everything you would want from a handheld LCR meter but its minimum stimulus is 300mV. Not bad, but not as good. Obviously a lot more money than a DE5000.For your purposes a bench LCR meter is probably vast overkill.

author: J-R
author_rank: Super Contributor
timestamp: March 22, 2024, 05:34:45 am
content: There is also this:https://www.peakelec.co.uk/acatalog/lcr45-lcr-impedance-meter.htmlSome negatives are the UI and test frequencies.

author: Fried Chicken
author_rank: Regular Contributor
timestamp: March 25, 2024, 01:38:43 am
content: I just ordered a DE-5000The Keysight would have been my preferred option, but at at least 3x the price, hopefully the DE-5000 will meet my needs and I can retire/sell the terrible alternatives I have.