| Author | Message | ||
| Darryl (Darryl) (68.184.123.198)
Rating: N/A |
Is anyone on the board running their 20" - 30" LCD TV on a modified sine-wave inverter? I haven't heard anyone mention how these sets do on the chop/chop stuff. When it comes to electronic things like these, it's hard to guess how they will react. | ||
| Gary Stadler (Boogiethecat) (68.7.217.217)
Rating: N/A |
Basically not a good idea. As you said, "it's hard to guess how they will react." This is true and the result MAY be "poof"... so why risk a $2000 TV trying to save money by using a cheap inverter....? | ||
| gillig-dan (68.107.231.43) Rating: N/A |
I used my flat panel monitor without any trouble. The only problems I've had with the modified sine wave inverter was a buzz in my cordless speakers and my 2 small air conditioners cannot run at the same time (even though they should, based on start-up load drawe). Also, anything and everything makes the speakers buzz. Most electronic equipment uses switching power supplies so, noise is filtered well. | ||
| Jim Stacy (209.247.222.100)
Rating: N/A |
We have beeen running a Samsung 17" LCD for 2 years without a problem. It actually runs on 12 VDC but I am using the AC adapter powered by a Heart MSW inverter. Can't tell if it's on inverter or shore power. Jim Stacy | ||
| Henry R. Bergman, Jr. (Henryofcj) (63.224.197.10)
Rating: N/A |
Could it be that some newer electronics actually clean up/create their own power from the outside source? Kinda like most computers? In which case the TV may not care what kind of wave form the input voltage may be as long as it is capable of cleaning it up. Perhaps one way of telling if a candiate TV would work with modified sine wave is to get a look at the wiring diagram? Beats me. | ||
| busone1 (4.4.12.34) Rating: N/A |
I could be wrong, which is not uncommon for me. I used to work with computer LCD screens and if I remember correctly they run off of DC current. Some have a seperate transformer and some have it built in to the screen. I bet the LCD TVs are the same. Anybody have one that can confirm? | ||
| Gary McFarland (Gearheadgary) (209.128.79.46)
Rating: N/A |
The ones I've seen are indeed as you say, in that they have a transformer and a DC Input. Typically this means you can feed it junk electricity and it's won't care. Gary | ||
| Gillig-Dan (63.111.68.130) Rating: N/A |
Just to add my earlier post... My flat panel is rated from 100 - 240 VAC. There's no need to switch voltages even. The power supplies take whatever voltage ther're fed, convert it to a raw DC, then back to a high frequency AC, then back to a filtered DC for the internal circuits. The more complicated switching circuit is actually cheaper to build and takes up much less space because it eliminates the need for the big filter capacitors and transformers. Older TV's used line frequency for picture sync. That's part of the reason European TV's scan at 50Hz and North America TV's scan is based on 60 hz. | ||
| Gary McFarland (Gearheadgary) (209.128.79.46)
Rating: N/A |
60Hz=Hi Freq? Ok, I'm splitting hairs. Gary | ||
| Gary Stadler (Boogiethecat) (68.7.217.217)
Rating: N/A |
Yeah Gar, Hi Freq. Switching power supplies as you see in almost everything these days work as follows (more or less): the incoming AC line is rectified to DC and filtered, and quite often doubled to 300 volts or so. Then a switching transistor (or fet, etc) switches this high voltage DC into AC at frequencies ranging from about 40khz up to a megahertz in some designs. This high frequency AC is now fed through a step-down transformer that can be very tiny considering the power going thru it (this is the whole point of a switcher... as frequency goes up, the amount of copper and magnetic material necessary to make a transformer of a given wattage goes accordingly down) The now reduced low voltage high frequency AC coming out of this transformer is finally rectified and converted back to DC for the doodah it is powering to use...and because of the transformer it is also isolated from the power line. Seems like a lot of stuff to go thru to make low voltage DC, but because of cheapness of mass produced electronic components, it's actually cheaper to do it this way than the old way of giant iron transformers that operate on 60hz... and the power supply is super tiny by comparison! ............... And the reason sometimes modified sine inverters can't be used with this type of power supply isn't so much that the switching supply can't take it; it usually can. The problems that usually show up are more because cheepo inverters put out so much RFI interference that lots of electronic things crap out due to it. Often times, no matter that "rules" say they have to be clean, they aren't, and often times that RFI will pass right thru a swiching supply and play havoc on the doodah that it is attempting to power. Fun with the soldering iron.... | ||
| Gary McFarland (Gearheadgary) (68.79.120.182)
Rating: |
You know what? A few minutes after I clicked "send" I thought: "wait, he's talking about switching freq, not supply freq" We're not even talking about AC supply anyway. I'm going back into my hole... Gary |
