Ruoshui 4091C ESR Meter: Overview, teardown, demonstration

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2 ай бұрын

In this video, I present the Ruoshui 4091C ESR Meter, one of the many brandings of what is apparently another 'brand-less' Chinese electronic product. I choose the RuoShui version over the (perhaps more common) equivalent East Tester ET44xx series and the Victor branded versions because I could only by those from Chinese sellers on eBay, whereas the Ruoshui was available from a seller on Amazon....as it turned out, it still ended up shipping from China. The upside was that I ordered a somewhat less versatile model, and the seller's warehouse accidentally shipped their top-of-the-line model.
This meter was entirely new to me when making this video, so viewers will watch along as I do an overview of the internal and external features, and do some experiments verifying its basic operations.

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@jwrtiger 2 ай бұрын

Thanks for the video. Tony Albus also did a nice review of a Ruoshui LCR Meter. He noted that the Ruoshui is probably a rebadged East Tester LCR Meter. I have the East Tester 4410 (100 kHz) unit. My unit's layout and circuit board look just like Tony's and your unit. You may note in your tear down that all three circuit boards have the East Tester Label ET44MV. M= model and V= version. Also I would recommend when you test large electrolytic capacitors you use a test frequency of 100 Hz for 50 Hz line frequency and 120 Hz for 60 Hz line frequency. Many data sheets use those test frequencies for the capacitor value because those capacitors are usually used in half or full-wave power supplies. I don't think testing an electrolytic capacitor using the DCR mode is a good idea. The DCR mode is good for resistors and wire components. The reason that your measurement on DCR was bouncing around is because the LCR Meter in that mode uses a very low frequency square wave going from 0 volts to 1.5 volts, (note on the meter's display the bias shows 1.5V). The meter makes the measurement when the square wave is in the high DC state of 1.5 volts. The problem when trying to make the DCR measurement on an electrolytic capacitors is that you are getting a value when the capacitors is charging and then of course it starts to discharges when the square waves is in its low state. The changing rate on the display of those values is the frequency of the test square wave. So basically not very useful information. I thought you did a very nice overview of this LCR meter and for the price I think they are a nice devices.

@youtuuba 2 ай бұрын

jwrtiger, thanks for the information. Regarding DCR, I think it is an important parameter to check with aluminum electrolytic capacitors. Indeed, a number of other (higher priced) ESR/DCR testers will check DCR first and then only proceed to the ESR test if the cap passed the first test. I see what you are saying about the testing points on a square wave influencing the DCR reading. My other two DCR testers only do that test with DC test voltages; it seems odd to me that this one would use anything but straight DC for this purpose. Luckily, as long as the DCR readings I get with this meter are not very low Ohms values, the cap is good and I don't need steady values on the display.