taiwan ebay sine inverters -- crap or good?

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Subject Author Date taiwan ebay sine inverters -- crap or good? z 12-27-2007  Re: taiwan ebay sine inverters -- crap or good? Neon John 12-27-2007  Re: taiwan ebay sine inverters -- crap or good? z 12-27-2007  Re: taiwan ebay sine inverters -- crap or good? z 12-27-2007  Re: taiwan ebay sine inverters -- crap or good? Neon John 12-28-2007  Re: taiwan ebay sine inverters -- crap or good? z 12-28-2007  Re: taiwan ebay sine inverters -- crap or good? Vaughn Simon 12-28-2007  Re: taiwan ebay sine inverters -- crap or good? Ulysses 12-28-2007  Re: taiwan ebay sine inverters -- crap or good? Neon John 12-28-2007  Re: taiwan ebay sine inverters -- crap or good? Ulysses 12-29-2007
Posted by z on December 27, 2007, 7:59 pm Please log in for more thread options I've been seeing these on ebay a lot http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=300184187331 at first they were all listed from Taiwan, but now I guess they are shipping from California. I need a sine inverter -- my crappy square wave inverter gives interference on some of my monitors. Also I like a clear radio signal etc. Any experience? I'm sure they aren't all that hot, given the price, but will they do? cheers -z Posted by Neon John on December 27, 2007, 8:50 pm Please log in for more thread options >I've been seeing these on ebay a lot > >http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=300184187331 > >at first they were all listed from Taiwan, but now I guess they are >shipping from California. > >I need a sine inverter -- my crappy square wave inverter gives interference >on some of my monitors. > >Also I like a clear radio signal etc. > >Any experience? I'm sure they aren't all that hot, given the price, but >will they do? It's probably OK - All of the other ChiCom inverters I've tested have been. But geez, $30 shipping? Sleazebay at its worst. Before you spend that kind of money AND take the efficiency hit (not a big hit but..), you might want to get your hands on a good multi-stage LC type EMI filter. Most of the surplus houses seem to have 'em all the time. This type of filter is basically a 60 hz low pass filter that chops off the higher harmonics that accompany the pseudo-square wave. If you look at the output on an O'scope, the edges of the square wave will be rounded significantly and the overall signal will look much more like a sine wave. This solution has almost always worked for me to get rid of hum lines and buzz in the audio and is much cheaper than a new inverter. John -- John De Armond See my website for my current email address http://www.neon-john.com http://www.johndearmond.com <-- best little blog on the net! Tellico Plains, Occupied TN Multitasking: Reading in the bathroom! Posted by z on December 27, 2007, 10:22 pm Please log in for more thread options > >>I've been seeing these on ebay a lot >> >>http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=300184187331 >> >>at first they were all listed from Taiwan, but now I guess they are >>shipping from California. >> >>I need a sine inverter -- my crappy square wave inverter gives >>interference on some of my monitors. >> >>Also I like a clear radio signal etc. >> >>Any experience? I'm sure they aren't all that hot, given the price, >>but will they do? > > It's probably OK - All of the other ChiCom inverters I've tested have > been. But geez, $30 shipping? Sleazebay at its worst. heh yeah. One did go for $125 recently so even with the shipping .. its not so bad. > > Before you spend that kind of money AND take the efficiency hit (not a > big hit but..), you might want to get your hands on a good multi-stage > LC type EMI filter. Most of the surplus houses seem to have 'em all > the time. I'll check that out. Not sure what a surplus house is -- I live in the serious boonies. Army surplus? But I've got friends in civ maybe they can find me one, or on the internets cheers -z Posted by z on December 27, 2007, 10:32 pm Please log in for more thread options > >> >>>I've been seeing these on ebay a lot >>> >>>http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=300184187331 >>> >>>at first they were all listed from Taiwan, but now I guess they are >>>shipping from California. >>> >>>I need a sine inverter -- my crappy square wave inverter gives >>>interference on some of my monitors. >>> >>>Also I like a clear radio signal etc. >>> >>>Any experience? I'm sure they aren't all that hot, given the price, >>>but will they do? >> >> It's probably OK - All of the other ChiCom inverters I've tested have >> been. But geez, $30 shipping? Sleazebay at its worst. > > heh yeah. One did go for $125 recently so even with the shipping .. > its not so bad. > >> >> Before you spend that kind of money AND take the efficiency hit (not >> a big hit but..), you might want to get your hands on a good >> multi-stage LC type EMI filter. Most of the surplus houses seem to >> have 'em all the time. > > I'll check that out. Not sure what a surplus house is -- I live in > the serious boonies. Army surplus? like one of these? Filter Concepts Inc model CF151F (CF151-F) EMI filter, rated for 115VAC, 15A input http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280186721967 Posted by Neon John on December 28, 2007, 4:28 am Please log in for more thread options >> I'll check that out. Not sure what a surplus house is -- I live in >> the serious boonies. Army surplus? No, electronic surplus. candhsales.com, surpluscenter.com, etc. > >like one of these? >Filter Concepts Inc model CF151F (CF151-F) EMI filter, rated for 115VAC, >15A input > >http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280186721967 That would be a good one to try. If you look here: http://www.filterconcepts.com/ac_filters.html You can get a good overview of filters. Look at http://www.filterconcepts.com/ac/sf_series.html vs http://www.filterconcepts.com/ac/sw_series.html The first is a mid-level filter and the second is a high performance unit. Look at the bottom of each page at the insertion loss at 50khz (0.050 Mhz). The more the better. The line/line spec of the high performance filter of 50dB means that it is a brick wall to 50 khz. It'll have considerable rolloff by probably the third harmonic of 60hz. You'd get something that looks pretty much like a sine wave out of it. The sleazebay one shows an insertion loss of 20dB at 20khz (why can't they keep the frequency uniform?) That's quite good and may approach the performance of the high performance filter above. It would certainly be worth $30. If you look at others at various surplus houses, you'll see that most of them have a diagram printed on the case that looks similar to the "schematic" in the above pages. Absent any other spec, the more stages (combo of choke and caps) the better. John -- John De Armond See my website for my current email address http://www.neon-john.com http://www.johndearmond.com <-- best little blog on the net! Tellico Plains, Occupied TN time. -Robert Half Similar Threads Posted Re: Modified Sine Wave Inverters - What is the down side? April 4, 2007, 9:10 pm WoW that was good Wine!!! September 9, 2007, 4:49 pm What do you see for the future of America? Good or bad, and why?... March 21, 2007, 8:52 am batt pulsers , any good ? 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