Power inverters

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MOAK

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G'morn everyone. I'm hoping on getting feedback from electrical engineers? Maybe? I've done a ton of research. I've been using regular old fashioned power inverters since the tube television was still around. Back when I was driving we needed a minimum of 800 watts to get the TV going. In todays electronic world all my wife and I need is enough power to charge up camera batteries, laptop, and iphones. For the record, everything is Macintosh. I'm still using that old Cobra 800 watt inverter. I've read from several sources that the world will come to an end if I keep using the old school inverter instead of shelling out more money for a "sine wave" inverter.. I understand the differences. I understand that damage can be done to modern appliances and flatscreens. I've even been berated for not switching to sine wave technology. I'm charging batteries. So far no problems. Without a second thought everyone plugs their phones into their vehicles and vehicles do not have a 12 volt sine wave converter. So, do I need to switch to "sine wave" to charge up the laptop battery or just leave well enough alone? Thanks for informed opinions !!
 

Flipper

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I have been an inverter geek from the beginning. I have had several square wave inverters and switched to a 2KW sine wave about 4 years ago back when they were pretty expensive, the price has dropped drastically the way technology is going they probably wont even be making square wave in a couple more years they will be compared to the old tube TVs to flatscreens.
First a sine wave and a square wave are two very different signals. In music a sine wave would be a clean tone a square wave would sound fuzzy, this is how they make a Fuzz Box for a guitar they cut the round peak off and make a square wave converting the clean note to a distorted fuzzy one.
Square waves are inefficient, dirty and cause heat. They are really bad for motors, compressors and charging batteries (battery chargers). My compressor for my fridge used to run so hot you couldnt even touch it. And will drastically shorten the life of your equipment.
I no longer get that interferring buzz in my audio system and radios. You could compare it to running crappy low octane gas to high test in a high performance engine.
I have had several bad experiences with the Xantrex square waves. Called them one time to get the schematics to troubeshoot one and their Techs were total zeros. Samlex seemed to be very cheap with terminals too small for the gauge wire required. I have had very good performance from Kisae. You can get these at Home Depot another great place with good customer service is DonRowe.com
Your question can I use a square wave, sure. You can run regular gas in a Porsche but it dosent like it at all. When you plug your phone into your car you are charging a DC battery from a DC source, no AC involved. Hope this helps.
 
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reh8388

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Since you are charging batteries the charges are converting the “AC” signal from the inverter back to DC voltage to charge the batteries. The chargers might take some additional abuse vs a pure sine wave but I wouldn’t be concerned. You can always look to see if you can get a DC to DC charger (like your car charger for you cell phone converts 12VDC to 5VDC) for your batteries and computer to eliminate the concern entirely.


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MOAK

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Since you are charging batteries the charges are converting the “AC” signal from the inverter back to DC voltage to charge the batteries. The chargers might take some additional abuse vs a pure sine wave but I wouldn’t be concerned. You can always look to see if you can get a DC to DC charger (like your car charger for you cell phone converts 12VDC to 5VDC) for your batteries and computer to eliminate the concern entirely.


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That would be impractical for our set up. The power inverter is located at the rear of our vehicle to charge things up over night. As we travel though, yes, the pads and phones are being charged from 12 volt sources from the dashboard.
 

reh8388

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That would be impractical for our set up. The power inverter is located at the rear of our vehicle to charge things up over night. As we travel though, yes, the pads and phones are being charged from 12 volt sources from the dashboard.
I must be missing something or am not explaining it properly. What is your inverter in the rear being powered from at night?


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MOAK

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A dual battery sytem in the cruser along with a 150 watt solar panel. We do sometimes spend 2 or 3 days at a basecamp without moving the vehicle. The Cobra inverter has a USB and two 110volt receptacles. We also run a 110 volt water pump, and use 110 volt LED camp lights. I'm thinking I've nothing to worry about. However, since a sine wave inverter is cleaner, that, I think would mean that it would also draw less amps to do the same thing as a non sine wave inverter. I have a very clean home stereo amplifier that cranks out a whopping 80 watts per channel that'll blow away cheapo amps that are cranking 150 or 200 watts per channel. In other words, I understand the "clean" sine wave power inverter over non clean conventional. Purchasing a 12 volt to 12 volt just wouldn't make any sense.