AC Test fittings for Zimmer LMG95 Power Meter - Page 1
Forum section: electronics / projects

author: PTR_1275
author_rank: Frequent Contributor
timestamp: January 12, 2016, 12:55:13 pm
content: Hi everyone,I recently purchased a Zimmer LMG95 power meter and so far I have been getting used to using it by running voltages in from my arb waveform generator, then testing it using DC from my power supply and running small DC loads (Testing inrush currents of globes and things like that). These tests have had no purpose other than learning my way around a new bit of kit before applying mains voltage to it.Zimmer sell a test fitting called the MAK1 and I cannot find much information about it other than what is pictured in the attachment. I am wanting to make up a similar adaptor myself for use in the workshop, probably a IEC one like Zimmer make and another one using standard Australian plugs / sockets.Normally I work on 12 and 24v DC, I am comfortable around 240v but I don't want to be overlooking anything. Are there any recommendations on boxes (thickness of material, type of material), 4mm safety sockets (Brands / part numbers to use or avoid)?? I am not sure if putting a circuit breaker in the active would be a wise move as a precaution, but I am open to suggestion.Because I still want to use this for DC loads I will probably make up a few breakout boxes for Anderson connectors which I use a lot of around the workshop, this will give me flexibility.I have been trying to get an idea of what other people do, but searching for the right terminology is probably where I am going wrong. What would you call this type of box?Thanks-Chris

author: quarks
author_rank: Frequent Contributor
timestamp: January 05, 2018, 07:43:19 am
content: unfortunately I have missed thisThe Lmg95 is one of the very best power meter you can get. In Germany (afaik) it is even used at PTB as a reference.have you made any progress you can share?

author: PTR_1275
author_rank: Frequent Contributor
timestamp: January 05, 2018, 03:08:58 pm
content: I contacted the Australian distributor and was quoted around $450 for the fixture. If it was a business with lots of people using it, sure I’d have no problems paying it. But for me, I can’t justify it when I know what the box contains (and it sure isn’t a lot of expensive stuff)Since this post I have made up a few leadsMy higher current dc lead uses Anderson connectors with banana Jax’s soldered on. The negative connects through, the positive has a break in it for current measurements and there are positive and negative at one end for voltage (nothing flash but did the job)For AC measurementI made a box, used it successfully and happily, then found tweaks that I would like to make, messed them up rendering the box useless. I then changed jobs and am only just getting the workshop set back up. All the equipment was mine, so it followed me when I left my job. The new job supplies all the equipment so now I have a awesome setup at home.The things I foundI really wanted a way to turn the load on / off without unplugging anything. This makes it so much easier to do inrush measurements. I landed tonuse a DPST switch on the output of the box so the LMG can still pick up voltages without there being an output to the load.Fuse on input (self explanatory), I don’t like to rely on fuses and I normally run unknown devices through the 1200va ac source before connecting to the mains just to make sure there’s no surprises waiting for me.Inlets and outlets. I was working on items with IEC inlets, so having a flying lead out of the test fixture straight to a IEC plug worked really wel. I then had a IEC inlet on the side of the test fixture. I planned to make one up with normal 3 pin plugs and sockets too.Labeling - make sure you label the box. I use JAC poly laser sheets a fair bit, durable and last a long time, so I had printed a label for the front of the box with lines of the connections. I didn’t want to look at this random box in a years time and forget what went where. Just a line schematic did the trick.I’d completely forgotten about his thread, but when I get off my backside and make the test fixtures again with all the changes, I’ll update here.As for the LMG, fantastic bit of gear. I was getting really frustrated with the scope view of the voltage and current waveforms taking ages to update. The digit displays would update fine, but it was just the waveform view that didn’t. Turned out the view window had been moved 15 seconds to the right, so the display was taking 15 seconds to update. Once I realized thisand moved the window back to where it should be, problem solved.

author: quarks
author_rank: Frequent Contributor
timestamp: January 06, 2018, 04:51:35 pm
content: thanks for the updatea few years back I build a break out box for my LMG95. I tested several shunt values for very low Standby Power measurementssee att. pic andhttps://www.eevblog.com/forum/projects/ac-test-fittings-for-zimmer-lmg95-power-meter/msg1393150/#msg1393150

author: PTR_1275
author_rank: Frequent Contributor
timestamp: January 10, 2018, 01:42:50 pm
content: Another thing that I remembered.I purchased a voltech load switch (PS1000) that allows you to measure inrush currents by turning the load on at 0 degree and 90 degreeI’ve not actually used it but it should make measurements more reliable. Once I get round to it I’ll do a tear down too, because I can’t find much information other than the voltech data sheet.