smoothing power inverters.

[bigpimp347]

ok..
just bought two power inverters 12v to 110v to run my 110v valve rig.
now these are damn noisy, right buzzing, on RX and TX, i know it's them as my last 240v to 110v (which melted) was fine..

so how is the best way to smooth these things..
they are 400w modified sine wave inverters..

i do have a bin on stand by just in case.

[kr0ne]

Bin it and get down the local trade suppliers for another transformer...

You do get some OK inverters but in my experience, if they're noisey then they are not worth the hassle. I think the vast majority are truly nasty. I would guess it's not a case of smoothing the output but of filtering the "sine wave" output...

[bigpimp347]

yes i figured this would be a pointless exercise so i bought a step down transformer last night 240v to 110v at 4.3amps so should be good enough..

i was going to get a builders transformer, but then i'd had to find space for a big yellow box and then get the sockets changed to US sockets etc..
so easier to get the right unit which i have..

anyone want any 12v DC to 110v AC inverters

[kr0ne]

Stick it on eBay under 'test equipment' as a 'broadband noise source'...

[packman]

make a wooden box and put foil or mesh over it we are off grid so we have inverters and charge contollers all in wooden boxes with foil/mesh and it works but its all in the inverters if off ebay they relly noisey but ones from maplin are not too bad

[duncan2]

Yes inverters output a near square wave. Never to be used in Hi-Fi look at the harmonics. If you can afford it buy a Sine wave converter distortion <3% they are dear but I think Jamco in the US do public versions a lot cheaper than the industrial versions. I have a 1500W inverter but would never use it for my Hi-Fi.

[kr0ne]

Yes inverters output a near square wave. Never to be used in Hi-Fi look at the harmonics. If you can afford it buy a Sine wave converter distortion <3% they are dear but I think Jamco in the US do public versions a lot cheaper than the industrial versions. I have a 1500W inverter but would never use it for my Hi-Fi.

Spot on!

[AndyWestcott]

For information, it is possible to get true sine wave inverters second-hand from some I.T. departments, as they are used in many UPS units.

Just get rid of the internal batteries and hook up a decent leisure battery of the correct voltage using nice heavy cable. Even doubles as a charger for the battery when you plug mains into it.

[bigpimp347]

i've since bought a proper transformer,
so the inverters have not been used for their intended purpose and will probably end up on ebay..!!

[AndyWestcott]

A conventional transformer is certainly the best way to go, none of those nasty harmonics.