Does this Wave Sign look ok to you ?

[Umpa]

I have a 500/1000 Watt modified sign wave inverter - it cost 20 quid from ebay. I have been quite happy with it and it powers all the stuff in my shed. The only gripe I have is it makes a loud clicking noise when I play my old 80's tapes on my 1990's midi hi-fi. When I use the Aux input with my phone, this is not so apparent due to he higher cleaner input.

Eventually the noise really started to grate on me, I thought I could handle it - but one day I saw red and decided bugger it I will buy a pure sign wave inverter. Won the bid on ebay -

[Umpa]

Something is wrong, it wont let me add any more text, so this is to say will you look at the pics and see if you know why the pure sifn wave inverter still make a clicking noise on my hi fi.

Both waveforms are shown in the pics.

[bcroe]

Any switching device is a potential radio noise generator. I would try putting a good RF filter
on the inverter output to see if it helps. Better shielding might also be needed. Bruce Roe

[Umpa]

Thanks, I should have thought of that, does the waveform look ok for a pure sine wave ?

[bcroe]

Thanks, I should have thought of that, does the waveform look ok for a pure sine wave ?

A scope is not the final word, you might use a distortion analyzer to get better info.
Bruce Roe

[Umpa]

I don't know what one of them is - lol, just trying to see if what I have is OK.

[inetdog]

Thanks, I should have thought of that, does the waveform look ok for a pure sine wave ?

To the naked eye, it looks OK. The other two pics are your old mod-square inverter? What is the frequency of occurrence of the clicks? Might it be coming from your Charge Controller instead?

[sdold]

If the clicking is the same with both inverters, then I don't think it has anything to do with the waveform since they are vastly different with the one in the middle pic being much closer to being a sine wave.

[Umpa]

Thanks guys, yes one is of the modified sine wave and the other the pure. Whilst it is a sine wave I think I can see a ripple in it, and did not know if that's what inverters do or causing the noise. I guess I am trying to figure out if the inverter is any good or not. Its the first one I have ever had, so no idea what it should really look like.

As for the clicking - yes it sounds the same, although much quieter on the pure although I was under the impression there would be no noise from this new inverter, so the disappointment was rather high - lol.

I'll keep at it and report back if I manage to sort it.

[sdold]

If it's much quieter on the "pure" sine wave inverter, then maybe there is something about the inverters. By the way, what about inetdog's question about the frequency of the clicks?. And whether or not it is coming from the charge controller?

[Umpa]

By the way, what about inetdog's question about the frequency of the clicks?. And whether or not it is coming from the charge controller?

I don't know how to test the frequency of the clicks TBH, and I don't know how to test if its coming from the CC or not. I will know more tomorrow because I have just installed an epever 4210AN, but it took me that long the sun had gone down before being able to have a proper play with it.

[Mike90250]

if from the solar, the clicks should stop when the sun goes down and charging stops

[Umpa]

if from the solar, the clicks should stop when the sun goes down and charging stops

As I read your reply I realised how stupid I am. I will have a go this afternoon.

[Umpa]

Ok, well I can report its def the inverter(s), however I have to say that its kind of the hi-fi that's to blame too. I also have an early 2000's micro hi-fi and thought I would try that, and it works perfect on both inverters. So I guess it has better filters inside it.

FWIW I tried my iMac on both inverters, it buzzed really bad on the modified, but perfect on the pure, so I guess its really down to a crappy hi-fi more than anything.

So that's all the hardware upgrade for this year. Just got to get a decent battery, to go with my new CC.
What do you guys think of this one :

https://www.ebay.co.uk/itm/Victron-Energy-12V-AGM-BATTERY-SOLAR-LEISURE-Energy-Storage-14-to-220Ah/301448582095?ssPageName=STRK%3AMEBIDX%3AIT&var=600395004931&_trksid=p2060353.m1438.l2649

Its expensive, so I need to make sure I have the charge power for it.

I have a 600W of panels.

[Mike90250]

...

So that's all the hardware upgrade for this year. Just got to get a decent battery, to go with my new CC.......

Its expensive, so I need to make sure I have the charge power for it.

I have a 600W of panels.

I don't know what your daytime loads are, or how well your panels are aimed, or how deeply you discharge your battery.
How long did the other battery last on your 600w of panels ?

Do you really need the expense of AGM ? Is the battery in your sleeping quarters?

Batteries want about 10% of their capacity, as charge current. If you only take a battery down 20-30% from full, it would recharge in 3-4 hours at 10% rate.

If you had 400ah of battery, you want 40A of charging.
600W @ 15V charge voltage = 40A So I'd guess 400ah is the largest your PV can support in good conditions. If you have a lot of clouds, or drain the battery deeply, you need more panel.