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Forum Index : Solar : Grid connected inverter off grid
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renewableMark Guru  Joined: 09/12/2017 Location: AustraliaPosts: 1678 |
Thanks Cheers Caveman Mark Off grid eastern Melb |
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Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498 |
That CRO is even cheaper on Aliexpress but will take a few weeks to arrive. There are only 10 types of people in the world: those who understand binary, and those who don't. |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
I bought one of these about a year ago, the kit was $30 then if I remember, from China and it took several weeks to arrive. This kit is ex stock Sydney, so even with the Christmas New Year break, should arrive much faster. At the time I was not expecting much, but was very pleasantly surprised. It is rather small, but it does produce a very sharp and bright display in vivid colour. It looks a bit weak in the photograph, but I suspect there was very bright ambient light for that photograph. So pleased with it I bought a second kit as a spare, which is still a plastic bag of unassembled bits. Its perfect for monitoring inverter waveforms. One other really nice feature of this, is that once you have tweaked the sweep speed, vertical sensitivity, vertical position, and trigger threshold, and scrolled your nice single sinewave horizontally into the exact centre of the screen, after any total power interruption it all comes back by itself exactly as originally set. You only have to stuff around once to set it all up. Cheers, Tony. |
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| hotwater Senior Member  Joined: 29/08/2017 Location: United StatesPosts: 120 |
Glad you still got good eyes, I need the big screen. At camp I use the Hantek 6022BE USB scope that only costs a few bucks more. Get a big laptop screen, nice and portable, displays voltage frequency and time, and you can save images to post later. Even comes with two scope probes, highly recommend getting a X100. Sure it is crap compared to what you can buy. Still it is 100 times better than what I started out in electronics with. |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
Have to agree. For an everyday general purpose oscilloscope this kit of parts would probaly be the ultimate "Ken and Barbie toy oscilloscope", and it certainly would try ones patience in that role. But if you can read the digits on a digital panel meter, this is about double the size of that, and perfectly adequate for quickly eyeballing a simple sine wave. Its at its very best hooked up for permanent full time monitoring maybe actually installed in the inverter itself, along with the usual voltmeter and amp meter. And the power used to run it is absolutely minimal. PCs and laptops are great, but they can be rather unwieldy and power hungry when running 24 hours for continuous permanent full time logging and monitoring. I built a bare bones BMS, to monitor thirty lithium cells, and it generates its own VGA output to drive a large flat screen monitor without needing a PC or laptop to do it. The BMS itself only consumes 1.5 watts. But switching on the monitor, it then shows a graphical display of 30 real time cell voltages, plus the max and min extremes reached for each cell during previous repeated daily cycling. It takes about a one second glance to take in relative state of charge, relative cell balance, which cell, and at what precise voltage triggered the charger turn off, and spot any gradually weakening cells. Have to agree, a nice big bright graphical display in colour does look rather nice. But for simple basic inverter output waveform monitoring, the "Ken and Barbie keyhole oscilloscope" can still be quite useful. Horses for courses, I guess... Cheers, Tony. |
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| renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678 |
I borrowed a hantek 6022 today, looks like the drivers have a problem with windows 10. I'll just have to wait for mine to come. Cheers Caveman Mark Off grid eastern Melb |
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| renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678 |
Frigg, I got the thing going by disabling driver signatures. This was the inverter  And this was the mains  So looks like I'm not using it right Cheers Caveman Mark Off grid eastern Melb |
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Ralph2k6 Senior Member Joined: 24/09/2017 Location: AustraliaPosts: 129 |
What voltage are you sampling? I wonder if you are getting signal clipping as you need to run maybe an x10 divider for your input signal due to the high voltage level. My little DSO toy, the one mentioned above can only handle 50v Pk, so I got a cheap x10 probe for it, or else it will be cooked. Ralph |
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| renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678 |
OK that was on 100x on the probe. I really have no idea how to use it, better look at some vids. Cheers Caveman Mark Off grid eastern Melb |
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| Ralph2k6 Senior Member Joined: 24/09/2017 Location: AustraliaPosts: 129 |
Hmm, there's also the ac/DC coupling mode for the scope to reference against.. Hopefully someone here who knows the devices better will pip in soon. U tube should have some resources  Ralph |
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Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1024 |
Just put together a little DSO150, just thought it could be useful to check the driver output on the control boards, Only need to see a good signal or waveform, tried it on my square wave inverter and it works well, but I will need to make or get a 10x probe before checking any output from the transformer, later if needed i may move onto something a little better. Cheers Aaron Cheers Aaron Off The Grid |
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| Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498 |
You could use a transformer. There are only 10 types of people in the world: those who understand binary, and those who don't. |
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| renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678 |
Bugger. that cro when set to 100 fried my pc, even the bloody hard drive. Not keen on plugging another one of those bastards into a pc again. Spent hours after setting up and doing all my logins again.  More e waste for the tip. Cheers Caveman Mark Off grid eastern Melb |
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| hotwater Senior Member Joined: 29/08/2017 Location: United StatesPosts: 120 |
PC? That would be bad. Sounds like you connected the probes ground lead to a live source and the PC was grounded to earth. Only a laptop "floats" and not to any real agency standards. Any time I see a flat top it is a good indicator that the input is clipped. There should always be some noise on the trace. I wish they would eliminate red as a trace color option and turn that section of the trace red that has reached the A/D limits. There is no AC input that removes the DC content. I have a capacitor with a clip attached handy for that. |
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| renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678 |
Well I did nothing good, bloody PC is toast. Did another one just 12 months ago from a power spike, I should have known better to back up properly. Lost a few pics, but not too much. Cheers Caveman Mark Off grid eastern Melb |
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| Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1024 |
That's one reason why I preferred a CRO with its own screen, in case something happens. Also battery powered this little CRO instead of a plug pack. Made it portable. (still getting some noise) Cheers Aaron Off The Grid |
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| Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
I have that noise problem too. Others have commented that the input stage on these can be a bit noisy, the display looks a bit "sparkley". But all things considered its a great little low cost gadget and ideal for monitoring the inverter output waveform. Its easy to be wise after the event, but as mentioned earlier a small transformer is a much safer (for the equipment) method of reducing and isolating the mains than a resistive divider. Cheers, Tony. |
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| Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1024 |
Found out my long battery lead was picking up some noise from power cords and other things. using the 12v transformer the results are pretty good. This was the wave on the HF inverter which looks ok, I could pick up the high frequency with some adjustment.  This one if from a YUK (Modified square wave) Plunged the transformer in and could here the buzzing.  This is a little Off topic but for us building our own solar system, inverters and other things I think an Oscilloscope weather it be a cheap one something off gumtree or ebay for the first time builder testing our gear, it may just pay for it self by saving a few components(fault finding) a long the way. Will do some more of this in the electronic section. Cheers Aaron Cheers Aaron Off The Grid |
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| Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498 |
Not having a cro is like trying to find your way out in the dark with both feet tied together. I had slight wave on the waveform of my inverter, turned out to be my old Trace inverter causing ripples as it was running the house. The old Trace won't do that again though, it completely sh*t itself last week. It was running but making funning noises and saying it could not sync to the grid which was not connected to. Anyway, it went off like Chinese new year and let out lots of smoke RIP. There are only 10 types of people in the world: those who understand binary, and those who don't. |
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| Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1024 |
The old Trace inverter did well for a while. I found that white smoke on circuit boards leaves a brown stain, even after washing it with soapy water, and it still smells a bit. Cheers Aaron Cheers Aaron Off The Grid |
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