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mike

On 6/26/2012 4:47 AM, wrote:
thanks Mike

So the best (safest) way would be to use a full sine wave inverter rather than the modified sine wave one?

On Monday, June 25, 2012 6:57:18 PM UTC-4, wrote:
Hi

In my little world, the plan is to use a 500W modified sine wave inverter to power a couple chargers that I can't seem to find the 12V equivalent for.

One would be a regular 110V Ryobi charger and the other a 110V charger for 9 Volt Ni-MH batteries.

After getting this stuff together I read that using an transformer with a inverter is bad. What would happen? Would I fry something?

Any insight would be appreciated

TIA

Bob

Well...the simple answer to the simple question is, YES.
Depending on the relative cost of sine and modified sine,
real sinewave is the safest.
BUT
You'll probably find that 99% of the time you'd be ok
with modified.
What's the cost of failure?

If you have a 99-cent 9V charger from China, I'd expect they're very
creative
in how it works. I'd worry more about the battery than the charger.
And if it smokes, so what?

The Ryobi is another matter. It's probably designed for abuse.
But you probably don't want to smoke a $100 charger and have it destroy
all your batteries.

First thing I'd do is call Ryobi.
Then I'd find a news group more suited to commercial guys who might use
one and ask there.

Failing that, I'd stick a current probe and oscilloscope on the power
line and look
at the peak currents with sine and inverter inputs.
If the peak current ain't too much greater, you're probably ok.

Don't forget to do the math.
If you expect to drive your truck to a remote job site and have
batteries on fast charge all day in your truck, you might have.
trouble starting the truck at the end of the day.