| Products > Test Equipment |
| Mastech MS5308 LCR meter with ESR measurement - on discount at the moment |
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| mrubbert:
1. @iloveelectronics, Yes. And it dosent look like a better practical or easier soldering place. 2. @alm, One of the on-board voltage regulators, either the 5 V or 3.3 V regulator, were specified for up to 8 V input, 10 V absolute max. There were a few diodes in series with the power input, but the voltage at the regulator was above 11 V. I installed an 7810 (with filter caps) between the DC power input and main PCB. This appeared to work fine, apart from the battery level indicator showing only two bars when on AC power. 3. I think 99% i have blown regulator. 4. Ofcourse its not to blame aidetech_us, they are trying to help us out. 5. Mastech was growing with 30% last year, 300 million $ +. (wonder why) They can afford to help custumers. 6.How long do YOU whant to wait: Distance Selling Regulations, which allow you to cancel the purchase within seven working days after the day you receive the item. You have to check if its accepted from the place you ordered from. |
| robrenz:
--- Quote from: PA4TIM on January 18, 2013, 08:51:07 am ---4 wire is most times for non bridge configurations by sourcing the test current through two wires and measuring the voltage result and phase between voltage and current direct at the DUT. This is the main reason they use it. Testsignal and resultsignsl are separted and so reducing errors. Whit to wire you can not measure phase error and this is the most important thing while trying to split an impedance into a resistive part and reactancet. Shielding or guarding the cables is again possibble to compensate for stray capacitance. But this is a very incompete and rough explanation. There are several general radio experimenters downloadable at IET labs that go in depth about all methods inluding a lot of math. Also the Agilent impedance measurement handbook goes into detail ( and they wrote some articles about measuring very small impedances. This is allways 3 or more wire. There is many literature about this, --- End quote --- Thanks PA4TIM that makes more sense now. From my analysis of the specifications of DE-5000 and The U1733C even though the U1733C is generaly more accurate, its lack of 4 wire connections realy shows with its poorer performance at the low end of of the low ranges of resistance and capacitance. This also makes its extra digit of resolution on its 2 ohm range meaningless. (+/- 500% of value at 1 milliohm) Edit; fixed chart These are the % of VALUE +/- max errors calculated from the % reading + counts specs of each unit. I used the most accurate Hz of each unit in each range. The highlighted values are the more accurate. |
| PA4TIM:
Compliments on the video made by jwrelectros. He shows the inside, does measurements agains known values ect. This is how i like reviews. But that resistance changing thing when using the AC adapter is real bad. And that wire soldered to a smd is weird. It was not weird if it was solving a problem until a new revision is made, the bad thing is it still has problems. I have a lot of precision stuff for measuring components but I like to have a handheld too. I had a Voltcraft ( looks like the extech but i did not liked it, under 10 pF it was useless, aircoils were also imposible to meaure correct so I traded that with a friend to a Tek TM5000 chassis and some plugins. But today I ordered the IET DE5000. Very nice snd helpfull people there. I had asked some information about an old GR bridge there a while a go and even then got a quick and helpfull repley. So I rather go for save and trust on the IET reputation as something like that Mastech with a too poor powersupply. In the price range that is sold, that is just a very major screw-up and if it was mine I had returned the hole meter. |
| nixxon:
--- Quote from: iloveelectronics on January 18, 2013, 04:17:41 pm ---I believe mrubbert is referring to around 29:26 of the video where you can see the power connections have clearly been changed from the original PCB design. --- End quote --- Thanks for pointing out the time in the video. Here is a screenshot of the actual components taken from the superb jwrelectros video. External power negative lead is connected to resistor "R16" and not to power connector, "P7", "GND". Maybe this setup is serving as a voltage divider. When I receive my MS5308, I will take a closer look at it. I wonder what the resistance is between either side of "R16" and "GND". Maybe the PCB was designed for 9 volts external power (less than 12 volts) and Mastech made this ingenious setup for the meter to handle a 12 volt power supply that was already designed for some other gadget? I am of course just speculating here... |
| nixxon:
Is the power supply problem really a problem? With a 14.5 mAh drain by the MS5308 and a set of 2269 mAh IKEA alkaline batteries (http://www.batteryshowdown.com/results-lo.html), you should get a run time of exactly 156 hours and 29 minutes ;). That is almost a week's, around the clock use (6.52 days)... You can measure a lot of L, C and R in that period of time ;D |
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