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beefy inverter

Let's say, for example, I had an old vehicle that I wanted to let sit
in the driveway and use as a backup generator (12VDC power
available). Nice that it already has a self-contained powerplant,
with a good emissions control system.

Let's say also that I wanted it to provide 1 kW of power, at 110 V.

Let's also say that I wanted to power inductive loads with it: an
electric saw, etc.

So, how would I go about building one of these puppies?

I know that the cheap square wave inverters from Wal-Mart would blow
up if I tried to run an inductive load off them.

Any suggestions? (posts to old Masters' Theses, etc?)

Michael
 
G

GregS

Jan 1, 1970
0
Let's say, for example, I had an old vehicle that I wanted to let sit
in the driveway and use as a backup generator (12VDC power
available). Nice that it already has a self-contained powerplant,
with a good emissions control system.

Let's say also that I wanted it to provide 1 kW of power, at 110 V.

Let's also say that I wanted to power inductive loads with it: an
electric saw, etc.

So, how would I go about building one of these puppies?

I know that the cheap square wave inverters from Wal-Mart would blow
up if I tried to run an inductive load off them.

Any suggestions? (posts to old Masters' Theses, etc?)

Michael

I still have the one I built. used a 555, some Mosfets, the core of an old
torroid variac, and thats about it. Not quite 1KW, maybe 600 watts.

greg
 
T

Tim Wescott

Jan 1, 1970
0
Let's say, for example, I had an old vehicle that I wanted to let sit
in the driveway and use as a backup generator (12VDC power
available). Nice that it already has a self-contained powerplant,
with a good emissions control system.

Let's say also that I wanted it to provide 1 kW of power, at 110 V.

Let's also say that I wanted to power inductive loads with it: an
electric saw, etc.

So, how would I go about building one of these puppies?

I know that the cheap square wave inverters from Wal-Mart would blow
up if I tried to run an inductive load off them.

Any suggestions? (posts to old Masters' Theses, etc?)

Michael
You'd probably find yourself overloading the car's alternator, unless
you went to the trouble to put in an auxiliary alternator in there --
and if you're going to do that, why not go find a clapped-out gen set
and fix it up?

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Posting from Google? See http://cfaj.freeshell.org/google/

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" gives you just what it says.
See details at http://www.wescottdesign.com/actfes/actfes.html
 
I still have the one I built. used a 555, some Mosfets, the core of an old
torroid variac, and thats about it. Not quite 1KW, maybe 600 watts.

greg- Hide quoted text -

- Show quoted text -


The mosfets didn't fry themselves when they saw an inductive load...?

Michael
 
R

Rich Grise

Jan 1, 1970
0
Eh, let's say it's a beefy alternator. 136A or so, like found on a
Dodge Ram.
http://www.partsamerica.com/productdetail.aspx?MfrCode=BAR&MfrPartNumber=1866473&PartType=11&PTSet=A

I used to work for a company that made inverters like that, but they
were big and heavy and expensive.

For what you would have to invest in any inverter, whether you build or
buy, you'd be better off to just go ahead and get a genset and fix it
up, or just buy a new one, for example:
http://www.brandsonsale.com/ht-001344.html

Good Luck!
Rich
 
I used to work for a company that made inverters like that, but they
were big and heavy and expensive.

For what you would have to invest in any inverter, whether you build or
buy, you'd be better off to just go ahead and get a genset and fix it
up, or just buy a new one, for example:http://www.brandsonsale.com/ht-001344.html

Good Luck!
Rich- Hide quoted text -

- Show quoted text -



"This unit can't be shipped to California and is only approved for
sale in 47 states".

Love that.

The good things about using an old vehicle are: 1) built in catalytic
converter; 2) EGR (exhaust-gas-recirculation) system to reduce NOx;
3) built-in muffler.

Oh well.

Thanks,

Michael
 
T

Tim Wescott

Jan 1, 1970
0
"This unit can't be shipped to California and is only approved for
sale in 47 states".

Love that.

The good things about using an old vehicle are: 1) built in catalytic
converter; 2) EGR (exhaust-gas-recirculation) system to reduce NOx;
3) built-in muffler.

Oh well.

Thanks,

Michael
On the other hand you're extracting 1kW from an engine that's good for
at least 30kW if it's wimpy, to 200kW for a big-normal pickup. So while
all the pollution equipment may be good when it's going down the freeway
at normal load, I question it's ability to hold the emissions down to
what you'd get out of a new California-approved genset.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Posting from Google? See http://cfaj.freeshell.org/google/

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" gives you just what it says.
See details at http://www.wescottdesign.com/actfes/actfes.html
 
On the other hand you're extracting 1kW from an engine that's good for
at least 30kW if it's wimpy, to 200kW for a big-normal pickup. So while
all the pollution equipment may be good when it's going down the freeway
at normal load, I question it's ability to hold the emissions down to
what you'd get out of a new California-approved genset.


Ah yes, you're absolutely right. I hadn't considered that.

Likely the EGR won't activate anyway while at idle. (I'd just
finished troubleshooting the EGR system on my car recently. What fun
that was.)

Thanks,

Michael
 
M

Michael Heydon

Jan 1, 1970
0
Let's say, for example, I had an old vehicle that I wanted to let sit
in the driveway and use as a backup generator (12VDC power
available). Nice that it already has a self-contained powerplant,
with a good emissions control system.

Running a car at idle for long periods (especially if you dont take it out
for a bit of a work out occasionally) will result in glazed bores. The
engine will go downhill quite quickly.

Also as others have mentioned, even a small 4cyl car engine at idle will
use more fuel and produce more pollution than a little 2 stroke genset
running flat out.

-- Michael
 
I still have the one I built. used a 555, some Mosfets, the core of an old
torroid variac, and thats about it. Not quite 1KW, maybe 600 watts.

greg- Hide quoted text -

- Show quoted text -


Do you have a schematic available, for those of us who are still
learning? ;-)

I don't currently have a.b.s.e. access (posting from work during
breaks), but I'll try tonight to see if I can get my DSL to log into
it.

Thanks,

Michael
 
Let's say also that I wanted it to provide 1 kW of power, at 110 V.

Let's also say that I wanted to power inductive loads with it: an
electric saw, etc.

So, how would I go about building one of these puppies?

Why on earth bother???

Here in the DK one can buy a noname Chinese petrol powered generator in the 2.5
kW power range for the equivalent of USD 200.
http://www.nettobuild.dk/shop/noedstroemsanlaeg-264c1.html

There is no way you can beat that!
 
"This unit can't be shipped to California and is only approved for
sale in 47 states".

Love that.



The good things about using an old vehicle are: 1) built in catalytic
converter; 2) EGR (exhaust-gas-recirculation) system to reduce NOx;
3) built-in muffler.

.....Needs service every 300 hours or so!!!

The early entrepreneurs into bio-gas (methane from pig's shite) learned that
there is a *reason* that engines rated for power plants and ships costs about
100 times that of the corresponding car engine :)

The average cheap Chinese genset will probably burn out in about 200 hours or
thereabouts also. But 200 hours cleaning the boat with a pressure washer is a
loong time.
 
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