power inverter help

[jacktors11]

Can someone please recommend a power inverter for the T-7? I work on the road as a sharpener, and need to bring my Tormek.  Thanks

[Herman Trivilino]

I would check your local home center or hardware store to see what's available.  You'll need lots of battery storage, too.

Do you know what kind of run times you'll be needing?   Given that we could make an estimate of the charge needed.  Will you have a generator on hand in case you run out of battery charge?
 

[MakerUnknown]

Tangential thinking here but is there way to convert it a treadle system?  Maybe using an old treadle sewing machine guts.  I don't have any idea how practical this would be?

[Mike Fairleigh]

Consider an inverter generator like the Honda EU2000i.

[Rob]

That would get my vote too.  The Honda's aren't the cheapest but I have the utmost respect for their reliability.

I have a Honda petrol garden mower that I bought new in 1994.  It had it's first service gratis from the supplier and I haven't touched it since.  Last year I noticed the engine sounding a little "farty" and the power dropping so I changed the plug and the oil....now its as good as new.

That poor little thing has been grossly neglected.....neh...positively abused by my lack of tlc for it and yet........it just keeps going.  It's quite the most reliable machine I've ever owned.

So if I get the chance...I buy Honda.

[jacktors11]

I just purchased a modified Sine 2000/4000 inverter and connected it to a Marine 12v battery. Well, the battery got sucked dry in no time.  I will look into the Honda that was recommended here. I hope that makes the difference. Another recommendation from the woodworking website suggested running parallel batteries.

As for run times, I usually run my Tormek about 1 hour a day. But that is turning it on and off at least 10 times a day.  I go from store to store, sharpening knives and scissors for my customers. I have a battery tender at home which i use to re-charge the battery when i  get home. But i need to have the battery last all day.

[Rhino]

I have a Honda 2000i and I love it. 

My only complain with the generator is that, if you don't plan to use for a few months, you got to drain the gasoline.  There is a valve for this.  Do it religiously.  It has a very small idle jet that is used in the economy mode.  If the jet clogs, then it will idle rough in economy mode.  If you just stick with regular mode, everything is fine.

You can take out the carburetor and clean the jet.  It is not hard if you are used to that type of thing.

[jacktors11]

Thank you for all of your help. I appreciate it. I will go for the Honda 2000i. The price is high, but it is just another investment into my business.

[jacktors11]

I just found this on Amazon.com:  This is 1/3 the price of the Honda, and almost all of the 187 reviews are 5 star. What do you think?

http://www.amazon.com/DuroStar-DS4000S-4-Cycle-Portable-Generator/dp/B004918MO2/ref=sr_1_20?s=lawn-garden&ie=UTF8&qid=1372784863&sr=1-20&keywords=honda+2000i+generator

[Mike Fairleigh]

It'll work as long as you aren't concerned with noise.  You won't be able to stand being anywhere near it for more than 10 minutes and you'll be considered the pariah of the neighborhood.

[jacktors11]

lol. i will just run in when i need power for my tormek, then i will shut it down. I will have it in my car.

[Rhino]

I got a generic generator too.  During a blackout I tried running it and the neighbors made me shut is off.  The neighbor was one of those complaining people but I guess she has a point too.

It is louder than a push lawnmower in use.  It sounds like your neighbor is cutting grass on a larger riding mower.

It is really not about how much you can stand, it is how much your neighbors (who is not getting any benefit from the noise) can tolerate.  If it is a business, it is how much your customer's neighbors can tolerate.

Also the weight.  I can lift the 2000i onto a pickup.  I cannot do so with the larger generator.  The oil change on the larger unit is once in 24 hours.  The oil change in the Honda is once in 70 hours (don't quote me on that).

The Honda 2000i can be used to charge your car battery.  But it is really an unregulated 30 volt output.  It it like one of those manual battery chargers in the old days.  Overcharge your battery and it will fry.  I tried to charge a friend's dead battery once, after 10 minutes, the battery still did not have enough juice to crank over.  I think you may need 30 minutes to charge a battery to start a car.

If noise and weight is not a problem, I say go for it.  It is a lot cheaper.

[Mike Fairleigh]

I've got a 5500W Generac that I keep in a storage unit since there is no other power there.  It's terrific, and I could bring it home to power stuff if I had to.  But it's like working next to a B-29.  I've wanted one of those Hondas for awhile now for other uses, portability, etc.  They also generate the least amount of RF noise of all the "small" inverter generators, in case that's a consideration.

[RobinW]

One aspect you should be aware of when using inverter drives with a motor is whether they are compatible.

A lot of inverter drives do not produce a sinusoidal output (they contain harmonics and other frequencies). The effect is these other components is to cause spurious induction effects within a motor (eddy currents) and these spurious currents seek alternative routes to earth. This is quite often through the motor bearings and results in bearing failure. Motors which are specifically used with inverter and variable speed drives are fitted with insulated bearings and other modifications to overcome these issues.

In the EU electrical equipment has to meet EMC (radiated and conducted) requirements so a lot of filtering is necessary. When inverter drives were introduced to the industrial world, the manufacturers left it to the buyer/installer to add on the necessary filtering to stop the emissions affecting other equipment. This has now changed and the equipment is generally supplied and compliant with the regulations. It does not however mean there are no additional frequency components in the output.

My advice is, should you consider operating your Tormek from a supply other than mains, check the state of the output. Likewise it would be worth submitting a question to Tormek and ask for  their views.

[Mike Fairleigh]

I agree with Robin about the fact that there can be "nasties" in the output of any inverter.  It's one of those cases where you often get what you pay for.  QST, a generations-old magazine dedicated to the amateur radio service, dives deeply into all kinds of things related to electronics.  They recently reviewed small inverter generators (an area of interest for radio amateurs since many of us like operating from remote locations).  They found that while none of them were perfect, the Honda had the "cleanest" output and was the most RF quiet, along with the other user-friendly features it has become famous for (quiet running, etc.).

Also, small AC motors that are either on or off tend to be pretty forgiving of their power supply, much more than electronically speed-controlled motors, solid state electronics, etc.

Still, Robin's point is correct.  No inverter provides true sine wave output until you get into the really big money.  Rather, they provide a square wave, or what some call a "stepped approximation of a sine wave."  In this realm (which includes all the small inverter generators), the more expensive the unit, the more "steps" in the wave, making it closer to a real sine wave.  Those $50 cigarette lighter inverters at Wal-Mart provide a stepped wave of about 5 steps - bottom, middle, top, middle, bottom.  That's really dirty output, but it'll work for some things.  In fact I have one in my truck that I sometimes use to power a small battery charger, which is electronically somewhat sensitive.