| Products > Test Equipment |
| XJW01 Auto LCR meter review ($120 bench top LCR meter) |
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| dannyf:
--- Quote ---Nice project to study. --- End quote --- Nice project. A very innovative design. - Cx@K3 produces the voltage across the DUT; Cy@K3 produces the current through the DUT. - sine wave produced through pwm; - the most interesting part is OP07 and V1/V2 as a phase detector: I have used similar designs in the ESR meter. It is a digitally controlled phase detector without resorting to analog switches - the typical implementation. - I didn't look at the software but he must be doing some fairly sophisticated math there. - He used a 8051. With a faster chip, he can simplify the design considerably and go much higher in frequency. - the calibration procedure is a little bit too complicated. But the fact that it is implemented at all is a huge plus. |
| nctnico:
I'm starting to like this little critter more and more. The good old HP4274A I bought a couple of months ago could not match it's capability to measure low resistance (tens of milli-ohms). Too bad it only supports a few frequencies. |
| quantumvolt:
Remote 'comparison' of XJW01 with Hameg HM8118 (new, in calibration - https://www.rohde-schwarz.com/us/product/hm8118-productstartpage_63493-44101.html). ... --- ... Since I saw the XJW01 meter on eBay, I knew I would buy one (https://www.eevblog.com/forum/testgear/xjw01-auto-lcr-meter-review-%28$120-bench-top-lcr-meter%29/msg429607/#msg429607). In general I like it a bit untidy, sloppy, dodgy ..., and I thought that if it is all junk I can always follow the safety seeking herd and buy a DE-5000 (I will buy that one too :-+). I have now had it about a year or so. I have had a lot of fun. To make a long story short I have collected quite a few quality caps (+- 0.5% and a few better). I have built oscillators and Wien bridges using Vishay precision resistors and 2x Agilent 34970A (AC range, interchanged bridge legs with relays) and a precision frequency counter. And a lot of math and statistical estimation / regression. All to determine the 'real' value of capacitors - and hence the errors of my XJW01. When I thought I knew the errors (for 'all' ranges, values and temperatures) of this box, I put in this ad https://www.eevblog.com/forum/buysellwanted/%28wtb%29-measurement-of-capacitors-%28from-calibrated-lcr-meter%29-%28paypal%29/. I got an answer from a very nice member here that has a Hameg (Rohde&Schwarz) precision LCR bridge at work. So I sent him the test caps to England and got the results back in email. Thanks a lot for his kindness. This comparison (3 weeks between measurements) of my XJW01 is anecdotal in the sense that it cannot in any way be generalized, but on a collection of high quality caps (180 pF to 33.3 nF - almost zero loss and almost zero temperature coefficient), my USD 99 (Best Offer) XJW01 meter was never more than 0.155 % off compared to the USD 1500+ Hameg lab instrument. :-DMM |
| Carrington:
Does anyone know where one can buy this other? And how much it cost? Source: http://www.crystalradio.cn/thread-373788-259-1.html Thanks. |
| happydad:
Can someone explain how the design calculates ESR? I assume that the actual V & I measurements give us impedance, which is not ESR. What am I missing? Thanks. |
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