Use of 12VDC-120VAC non-sinusoidal inverters
Use of 12VDC-120VAC non-sinusoidal inverters
(OP)
I'll be travelling off-site from work where my primary power source is 12VDC automotive. Was considering using a few hundred watt non-sinusoidal 12VDC to 120VAC inverter to power the battery chargers for the laptop and camcorder.
However, reading the manuals for the laptop/camcorder, they advise against the use of such inverters since overheating and damage may occur. Are these warnings justified? Any good or bad personal experiences?
Thanks
-AK2DM
However, reading the manuals for the laptop/camcorder, they advise against the use of such inverters since overheating and damage may occur. Are these warnings justified? Any good or bad personal experiences?
Thanks
-AK2DM
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"It's the questions that drive us"
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RE: Use of 12VDC-120VAC non-sinusoidal inverters
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If we learn from our mistakes I'm getting a great education!
RE: Use of 12VDC-120VAC non-sinusoidal inverters
Dan - Owner

http://www.Hi-TecDesigns.com
RE: Use of 12VDC-120VAC non-sinusoidal inverters
The PFC ones? They would care a lot! (briefly)
Keith Cress
kcress - http://www.flaminsystems.com
RE: Use of 12VDC-120VAC non-sinusoidal inverters
http://www.rediline.com/redilit.
As I recall they are pricey, but rugged. Many of the power utility trucks in this area use them.
RE: Use of 12VDC-120VAC non-sinusoidal inverters
Obviously try open circuit, laptop and camcorder not connected, to start - watch for failure and check output voltage.
Then monitor for excess heat under worst case (charging and operating at same time).
RE: Use of 12VDC-120VAC non-sinusoidal inverters
Looks like my concerns may be justified.
Not sure if they have active PFC, I think I will play it safe and try to obtain 12V powered chargers from the manufacturers.
Could alway record a 60Hz sine on my MP3 and play it back through the stereo and tap off the subwoofer amp to power the chargers :)
Thanks Again
-AK2DM
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"It's the questions that drive us"
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RE: Use of 12VDC-120VAC non-sinusoidal inverters
RE: Use of 12VDC-120VAC non-sinusoidal inverters
RE: Use of 12VDC-120VAC non-sinusoidal inverters
The active PFC simply tries to draw a current waveform from the source that is similar to the voltage waveform - and in phase with it. That can hardly be a problem.
It could be a problem if the source impedance were low (PSCC high), but it is not in a device rated a couple of hundred watts and which is fed from a 12 V battery. Probably also with some resistance in the connecting cables.
I have used inverters with square wave, stepped (stair-case) square wave and also sine outout. Of those, the sine output inverter died quickly. But the square wave and stepped square wave inverters still live. And I have not killed any load connected to them so far.
The best solution is to buy 12 V mains adapters for your computer, phone and what have you. All you need an inverter for then is your specialized measurement equipment. That part, I have solved by using USB instruments. They are smaller, lighter and better in many respects than their mains-fed brethren. At least if you work with signals below a few hundred MHz.
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: Use of 12VDC-120VAC non-sinusoidal inverters
My former colleagues in the IT department put one of their expensive rack-mounted active PFC-corrected UPS units on the output of the central UPS (stupid idea I know, but...) and their UPS front end burnt up. The central UPS was a rather poor design and the output voltage had a triple zero crossing and massive distortion which the active PFC tried unsucessfully to follow. I don't know if all active front ends try to mimic the voltage waveform, but those that do seem to be optimised for sinusoids.
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If we learn from our mistakes I'm getting a great education!
RE: Use of 12VDC-120VAC non-sinusoidal inverters
A central UPS usually does have a low internal impedance. What I was discussing - and I hope what the OP meant - was the small 100 - 200 W units.
Quote: "It could be a problem if the source impedance were low (PSCC high), but it is not in a device rated a couple of hundred watts and which is fed from a 12 V battery. Probably also with some resistance in the connecting cables"
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...