Is this due to a bad design ?, will it hurt if i run my computer or other electronics on it like led tv's

 

I think it's not a good design. I don't know if it will hurt your computer. Who made it?

 

I think it's not a good design. I don't know if it will hurt your computer. Who made it?

Its a Chinese inverter, i am very satisfied with it expect that it got the buzzing noise problem, i got 3 laptops running on it and 2 led screens that i don't want to damage.

 

May I ask why you are using in inverter? Are you running on solar power? And is your inverter very heavy or is it light? My guess is that it is heavy and so uses a big old low frequency transformer. Better designed sine wave inverters use small transformers and PWM switching at high frequency.

You might try using small capacitors across the output leads. If you can determine the frequency of the ringing, you can use Xc=1/(2∏c) to calculate the impedance of the capacitor at the ringing frequency. Alternatively, you can use an L-C filter or even a ferrite suppresser, which you can get form Radio Shack.

 

I got a 600W wind turbine and a 600 Ah battery bank so i use the inverter with that setup, i will try the capacitor and see where it goes from there. but i wish some one could answer my question about if this interferance would cause any damage to the devices that i am running ?


Regarding the weight of the inverter, it weighs 3kg and its a 1000W

 

I got a 600W wind turbine and a 600 Ah battery bank so i use the inverter with that setup, i will try the capacitor and see where it goes from there. but i wish some one could answer my question about if this interferance would cause any damage to the devices that i am running ?


Regarding the weight of the inverter, it weighs 3kg and its a 1000W

If the equipment is audio, I don't think it will have a damaging effect, but I'll be cautious to use it on sensitive digital processing equipment such as computers.

Do you have an earthed (grounded) neutral on your inverter?

 

If the equipment is audio, I don't think it will have a damaging effect, but I'll be cautious to use it on sensitive digital processing equipment such as computers.

Do you have an earthed (grounded) neutral on your inverter?

All the stuff running on the inverter is electronics 3 computers and 2 LED screens.

the inverter is not grounded but if that makes a difference i will for sure give it a try.

 

All the stuff running on the inverter is electronics 3 computers and 2 LED screens.

the inverter is not grounded but if that makes a difference i will for sure give it a try.

In most cases, it is a requirement that the output "neutral" should be grounded, mostly for protection purposes, but it might help in your case. Please give us feedback on this also.

 

i will try the capacitor and see where it goes from there.

Don't go over a couple hundred nF, or else you'll have a lot of surge current. If things improve, you might want to go back and try a L-C filter.

 

the smallest cap i got around is 7 micro F so obviously i will need to get a lower value, i will ground the inverters neutral and install the cap and let you guys know the results.


I relay appreciate the help from you guys, Thanks

 

I tried a 1 Micro F cap first and it didn't do any thing, then on the second try i grounded the neutral on the inverter and the buzzing annoying noise was gone. Thanks guys for the help


But i would be very interested in knowing what is happening inside the inverter that causes this buzzing sound and if it is left untreated what damage can it do ?

 

Are you saying the noise is gone when you use a capacitor filter AND ground the neutral wire?

 

Are you saying the noise is gone when you use a capacitor filter AND ground the neutral wire?

No

I tried the capacitor first and it didn't change any thing so i removed it and tried to ground the neutral, after grounding the neutral the buzzing noise was gone

 

There are two ways to make a sinewave output inverter. One is linear - with a true analog sinewave into a power amplifier into the primary of a step-up transformer. The other is switching - a pulse width modulated squarewave into the primary of a step up transformer. Sounds like you have the latter, and are hearing a beat frequency from the PWM. Depending on exactly where the EMI source is, a shielded line cord might help.

ak

Exactly, and when one of the conductors of the output line cord is connected to ground, you effectively get the shielding effect due to its close proximity to the live conductor.