Author Topic: need a junk inverter  (Read 2298 times)

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Norm

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need a junk inverter
« on: June 10, 2010, 02:18:09 PM »
I have been thinking of making an E-bike ....home brew  a corded small electric drill and inverter
to run it trouble with having an inverter when the battery gets so low ....it cuts out.....
don't really need that...the drill could run on 80 or 90 volts wouldn't even need 60 cycle
......anyone got an old junk inverter 2 or 300 watts that keeps kicking out ? that I could
maybe bypass that part?

ghurd

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Re: need a junk inverter
« Reply #1 on: June 10, 2010, 02:32:45 PM »
You want an inverter that has no under-voltage shutdown?
I can not help you with that.

Is the drill an old single speed?
The surge current is pretty high with those,
which makes the battery voltage dip,
which can shut down the inverter.

The variable speed ones have less surge if the trigger is squeezed instead of pulled fast,
but some of them do not like MSW inverters, or so I hear.
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dave ames

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Re: need a junk inverter
« Reply #2 on: June 10, 2010, 02:37:17 PM »

 hey norm,

 could be that you can get away without the inverter. lots of these drills run ac/dc

my little 3/8" b&d #7196 runs fine on anything over 24vdc..really need 48v to get much umph though. yours might be the same? worth a shot if your just fooling around?

cheers, dave

TomW

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Re: need a junk inverter
« Reply #3 on: June 10, 2010, 02:56:10 PM »

 hey norm,

 could be that you can get away without the inverter. lots of these drills run ac/dc

my little 3/8" b&d #7196 runs fine on anything over 24vdc..really need 48v to get much umph though. yours might be the same? worth a shot if your just fooling around?

cheers, dave
Then if it can use DC you might have better surge luck running the inverter output thru rectification to some big beer can caps and then to the drill as DC? That is pretty spooky DC levels probably 180 volts but is another idea to use what you got. Depending on the inverter it might have half the output volts from "hot" to "ground" so could do some electrickery to get a lower DC volts and more current?


I have a small herd of 15,000 microfarad 100 Volt electrolytic caps I will never use all of them.  I would gladly send you a box of 6,8 or whatever you need. Would need them in series to handle the volts and in parallel for oomph. Easily get you enough to play with.

This way the caps should supply the surge once its running and maybe get you past that power draw dip.

Probably lots of problems with the idea but there it is. Might create a heck of a light show and arc fest but I would try it.

Oh I have some big diode packs that could handle that power and voltage too sitting right here on my desk from Drives Dean.

Glen, bring on the reasons he shouldn't do this [if any]  ;D

Tom

ghurd

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Re: need a junk inverter
« Reply #4 on: June 10, 2010, 03:05:24 PM »
"bring on the reasons he shouldn't do this [if any]"

Because 180VDC scares the poo out of me?

If it has any electronics in the trigger, it'll probably smoke?

I know Jerry had a high voltage battery bank (144VDC) at the stereo shop that he powered "old single speed power tools" from.
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zap

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Norm

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Re: need a junk inverter
« Reply #6 on: June 10, 2010, 05:25:48 PM »
Guys gave me an idea....think I'll see what a small saw, a cheap right angle grinder or corded drill
will do on 48 volts, like Ghurd says.....180 volts makes me nervous.
Let you know the results......
thanks for the help and suggestions!

RP

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Re: need a junk inverter
« Reply #7 on: June 10, 2010, 11:01:34 PM »
Norm,  Go to a yard sale and buy a cordless 12volt or 14 volt drill with a shot battery pack.  Then you can get full power from a 12 volt SLA.

A lot of the cheap Skill and Black and Decker cordless drills came out with really bad NiCd chargers that cooked the batteries so you might find one for a couple bucks.

I've got a 14volt Skill drill that I converted to be corded with some 10 gauge speaker wire and large alligator clips.  I use it at the farm by clamping it onto any vehicle battery.