I bought a Trippe Electric 400 watt square wave resistive load only 12v.
inverter at a yard sale. I hooked it up directly to a 12v. battery, and put
in a 110v. test light, the small two prong ones. I flipped the switch, and
couldn't get the test light to come on.

Do I need to hard wire this to the 12v. system? Maybe there wasn't enough
juice in the battery to kick the light on?

I did hook it to a 12v. cigarette plug, and promptly burned out the 5 amp
fuse. I put a 30 amp fuse in there, and it burned that out, too.

What does resistive load only mean? and square wave?

Am I farting in the wind? I need to hook up a laptop in my truck for
business purposes. Should I just go get the cigarette plug inverter they
sell at the computer store?

TIA

Steve

--
"...the man who really counts in the world is the doer, not the mere
critic-the man who actually does the work, even if roughly and imperfectly,
not the man who only talks or writes about how it ought to be done."
Theodore Roosevelt 1891

On Thu, 25 Sep 2008 21:46:03 -0800, "SteveB" toquerville@zionvistas
wrote:



What does resistive load only mean? and square wave?

It essentially means heaters and incandescant lights, no motors.

On Thu, 25 Sep 2008 21:46:03 -0800, SteveB wrote:

400 watt square wave resistive load only 12v

400 W / 12 V = 33 A, so at full power it will burn out
both of your fuses. This is probably not the reason though
because you didn't fully load it; still, inverters tend
to have a large turn-on current draw, to charge up
the internal capacitances and inductances.

To test it, I'd hook it to a 12V/few amps power supply, and check
the 120V output with an AC voltmeter, and perhaps with a 100W
lightbulb (I have one mounted in a socked with a standard 2-blade
plug--probably available in any hardware store). From your description
however, I would suspect that your inverter is non-functional.

BTW laptop power supplies are not straight-resistive---but since their
power is much less than 400W you might get away with it.





--
Przemek Klosowski, Ph.D. przemek.klosowski at gmail

"SteveB" wrote: (clip) Should I just go get the cigarette plug inverter
they
sell at the computer store?
^^^^^^^^^^^^^^^^^
Based on the questions you are asking and your description of what you have
done so far, I would say you should buy an inverter. Don't take a chance on
damaging your computer trying to save $30-40,

Leo Lichtman wrote:
"SteveB" wrote: (clip) Should I just go get the cigarette plug
inverter they
sell at the computer store?
^^^^^^^^^^^^^^^^^
Based on the questions you are asking and your description of what
you have done so far, I would say you should buy an inverter. Don't
take a chance on damaging your computer trying to save $30-40,

I found a 12v supply for my laptop on ebay , for under 20 bucks shipped .
The mfr wanted more than that to send me just the plug I needed ... the
supply was a bonus !
--
Snag
computer geek in training

On Fri, 26 Sep 2008 05:48:56 -0500, "Terry Coombs"
wrote:

Leo Lichtman wrote:
"SteveB" wrote: (clip) Should I just go get the cigarette plug
inverter they
sell at the computer store?
^^^^^^^^^^^^^^^^^
Based on the questions you are asking and your description of what
you have done so far, I would say you should buy an inverter. Don't
take a chance on damaging your computer trying to save $30-40,

I found a 12v supply for my laptop on ebay , for under 20 bucks shipped .
The mfr wanted more than that to send me just the plug I needed ... the
supply was a bonus !
Second son has the 800 watt inverter supply that I found one Saturday
morning. Asked the guy "How much?", His reply "Make an offer, it's
been sitting in the garage since I bought it, never got around to use
it." I quite happily gave him $2 figuring that the heat sink was worth
that for scrap.
Gerry :-)}
London, Canada

"SteveB" toquerville@zionvistas writes:

I bought a Trippe Electric 400 watt square wave resistive load only 12v.
inverter at a yard sale. I hooked it up directly to a 12v. battery, and put
in a 110v. test light, the small two prong ones. I flipped the switch, and
couldn't get the test light to come on.

Do I need to hard wire this to the 12v. system? Maybe there wasn't enough
juice in the battery to kick the light on?

I did hook it to a 12v. cigarette plug, and promptly burned out the 5 amp
fuse. I put a 30 amp fuse in there, and it burned that out, too.

400 watts at 12 volts is 400/12 = 33.33... amps. A 5 amp fuse doesn't
have a chance, and a 30 amp is marginal. But if you're going to plug
it into a circuit designed around 5A (as indicated by the
pre-existing fuse), putting in a 30A fuse and trying is just begging
for melted wires or worse. Be glad the fuse blew.

The battery should be no problem -- a car battery (from context,
that's what I'm assuming) can happily supply 600A or more.

What does resistive load only mean? and square wave?

A resistive load is basically anything except a motor -- basically,
does the current equation I=V/R hold? For things like resistors,
lights (like what you used for testing), heaters it does. The other
alternative is an inductive load, for which the current lags the
voltage. Big motors are inductive loads.

Square wave describes the shape of the AC output. You've seen the
drawings showing what AC looks like as gently rising to full voltage,
smoothly turning over, gently falling.... that wave shape is a sine
wave. A square wave slams up to the full voltage, stays there, then
slams down to negative full voltage -- a picture of it looks square.
Pretty much everything in the universe that wants AC input is designed
around a sine wave (since that's what the commercial power in your
house provides), some but not all would be damaged by a square wave.

Am I farting in the wind? I need to hook up a laptop in my truck for
business purposes. Should I just go get the cigarette plug inverter they
sell at the computer store?

Yes. You want the cigarette plug adapter. It's easy, cheap, and
(most importantly) designed to convert 12VDC to whatever your laptop
wants (and DC) simply and efficiently.

The inverter is trying to convert 12VDC to a half-assed 120VAC so your
laptop power brick can then convert it back to whatever your laptop
wants. That's a really unnecessary amount of extra work.

DC-AC power inverters are basically a bad idea; they're complicated,
inefficient, fragile, and can damage the AC equipment you're hooking
them up to if that equipment is also fragile. They should only be
used if you don't have another choice.

On 2008-09-26, SteveB toquerville@zionvistas wrote:
I bought a Trippe Electric 400 watt square wave resistive load only 12v.
inverter at a yard sale. I hooked it up directly to a 12v. battery, and put
in a 110v. test light, the small two prong ones. I flipped the switch, and
couldn't get the test light to come on.

Do I need to hard wire this to the 12v. system? Maybe there wasn't enough
juice in the battery to kick the light on?

I did hook it to a 12v. cigarette plug, and promptly burned out the 5 amp
fuse. I put a 30 amp fuse in there, and it burned that out, too.

What does resistive load only mean? and square wave?

Am I farting in the wind? I need to hook up a laptop in my truck for
business purposes. Should I just go get the cigarette plug inverter they
sell at the computer store?

Your laptop power supply is not a resistive load. It may be sensitive
to voltage spikes produced by this cheap inverter. It is also not
clear what is the output frequency of this inverter (your resistive
loads do not care about frequency).

If your inverter burned out fuses, that means that you probably saw
sparks when connecting it to a battery and it is most likely bad.

Square wave means that your inverter produces +110v half the time and
-110v half the time.

I use a cigarette lighter inverter for my laptop and it works
great. My laptop runs Linux, so it may use a tad less power than a
Windows laptop, but the cigarette lighter inverter has enough capacity
in any case.

--
Due to extreme spam originating from Google Groups, and their inattention
to spammers, I and many others block all articles originating
from Google Groups. If you want your postings to be seen by
more readers you will need to find a different means of
posting on Usenet.
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"SteveB" toquerville@zionvistas wrote in message
news
I bought a Trippe Electric 400 watt square wave resistive load only 12v.
inverter at a yard sale. I hooked it up directly to a 12v. battery, and
put in a 110v. test light, the small two prong ones. I flipped the switch,
and couldn't get the test light to come on.

Do I need to hard wire this to the 12v. system? Maybe there wasn't enough
juice in the battery to kick the light on?
snip

Did you align it with the Earth's magnetic pole? I thought not!

On Thu, 25 Sep 2008 21:46:03 -0800, "SteveB" toquerville@zionvistas
wrote:

I bought a Trippe Electric 400 watt square wave resistive load only 12v.
inverter at a yard sale. I hooked it up directly to a 12v. battery, and put
in a 110v. test light, the small two prong ones. I flipped the switch, and
couldn't get the test light to come on.

Do I need to hard wire this to the 12v. system? Maybe there wasn't enough
juice in the battery to kick the light on?

I did hook it to a 12v. cigarette plug, and promptly burned out the 5 amp
fuse. I put a 30 amp fuse in there, and it burned that out, too.

What does resistive load only mean? and square wave?

Am I farting in the wind? I need to hook up a laptop in my truck for
business purposes. Should I just go get the cigarette plug inverter they
sell at the computer store?

TIA

Steve


Maybe it was at the garage sale because it was no good???

Steve,
Never use anything but sinusoidal power for electronics, damage to the
electronics would be very likely. Plugging a laptop directly into your
cigarette lighter without a regulator in beween will also kill your laptop.
Please keep in mind that vehicle 12 V could very often be as high as 15 V
when the engine is running and would be unfiltered as well as unregulated.
Steve

"SteveB" toquerville@zionvistas wrote in message
news
I bought a Trippe Electric 400 watt square wave resistive load only 12v.
inverter at a yard sale. I hooked it up directly to a 12v. battery, and
put in a 110v. test light, the small two prong ones. I flipped the switch,
and couldn't get the test light to come on.

Do I need to hard wire this to the 12v. system? Maybe there wasn't enough
juice in the battery to kick the light on?

I did hook it to a 12v. cigarette plug, and promptly burned out the 5 amp
fuse. I put a 30 amp fuse in there, and it burned that out, too.

What does resistive load only mean? and square wave?

Am I farting in the wind? I need to hook up a laptop in my truck for
business purposes. Should I just go get the cigarette plug inverter they
sell at the computer store?

TIA

Steve

--
"...the man who really counts in the world is the doer, not the mere
critic-the man who actually does the work, even if roughly and
imperfectly, not the man who only talks or writes about how it ought to be
done." Theodore Roosevelt 1891

Steve Lusardi wrote:

Steve,
Never use anything but sinusoidal power for electronics, damage to the
electronics would be very likely. Plugging a laptop directly into your
cigarette lighter without a regulator in beween will also kill your laptop.
Please keep in mind that vehicle 12 V could very often be as high as 15 V
when the engine is running and would be unfiltered as well as unregulated.


The spikes can be as high as 400 volts on the battery bus in a
vehicle, and still meet specifications. Delco used to protect their
early transistor car radios with a 'Spark Plate' which was a square
piece of very thin pc board soldered to the case, and used as a terminal
between the switch and the vehicle's electrical system.

The square wave is low enough in frequency to use with normal
silicon diodes, but at higher frequencies would fail. A standard switch
mode CDC-DC power supply uses square waves without any filtering of the
harmonics. A stepped, or 'quasi' sinewave inverter is only going to
charge the electrolytics at the peak voltage anyway. In this respect,
the square wave is better for the simple diode doubler used in typical
computer power supplies.


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There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.

On Fri, 26 Sep 2008 18:30:17 -0400, "Michael A. Terrell"
wrote:


Steve Lusardi wrote:

Steve,
Never use anything but sinusoidal power for electronics, damage to the
electronics would be very likely. Plugging a laptop directly into your
cigarette lighter without a regulator in beween will also kill your laptop.
Please keep in mind that vehicle 12 V could very often be as high as 15 V
when the engine is running and would be unfiltered as well as unregulated.


And "most" laptop power supplies run at a nominal 18 volts, making the
15 volt fluctuations a total non-issue - while the battery (if
installed) in the laptop makes a very effective filter for those
extremely brief "400 volt" spikes.

I've run several laptops off the cig lighter over the years with no
ill effect. The Compac LTE is still around in operating condition
along with the Thinkpad 600 and 700 series.

The spikes can be as high as 400 volts on the battery bus in a
vehicle, and still meet specifications. Delco used to protect their
early transistor car radios with a 'Spark Plate' which was a square
piece of very thin pc board soldered to the case, and used as a terminal
between the switch and the vehicle's electrical system.


Those old Delco systems were still running electromechanical
regulators on generators too - or POSSIBLY electromechanical
regulators on alternators (early delcotrons)
The square wave is low enough in frequency to use with normal
silicon diodes, but at higher frequencies would fail. A standard switch
mode CDC-DC power supply uses square waves without any filtering of the
harmonics. A stepped, or 'quasi' sinewave inverter is only going to
charge the electrolytics at the peak voltage anyway. In this respect,
the square wave is better for the simple diode doubler used in typical
computer power supplies.

Correct.
** Posted from http://www.teranews.com **

clare, at, snyder, dot, ontario, dot, canada wrote:

On Fri, 26 Sep 2008 18:30:17 -0400, "Michael A. Terrell"
wrote:


Steve Lusardi wrote:

Steve,
Never use anything but sinusoidal power for electronics, damage to the
electronics would be very likely. Plugging a laptop directly into your
cigarette lighter without a regulator in beween will also kill your laptop.
Please keep in mind that vehicle 12 V could very often be as high as 15 V
when the engine is running and would be unfiltered as well as unregulated.


And "most" laptop power supplies run at a nominal 18 volts, making the
15 volt fluctuations a total non-issue - while the battery (if
installed) in the laptop makes a very effective filter for those
extremely brief "400 volt" spikes.


Do you really think the battery is connected directly to the DC
input? That's beyond funny.

If you ever experience a 'load dump' while driving, you'll be trying
to hold on to the steering wheel while tossing a flaming laptop out the
window and breathing toxoc fumes. I just hope you don't kill anyone
else in the proces.


I've run several laptops off the cig lighter over the years with no
ill effect. The Compac LTE is still around in operating condition
along with the Thinkpad 600 and 700 series.

The spikes can be as high as 400 volts on the battery bus in a
vehicle, and still meet specifications. Delco used to protect their
early transistor car radios with a 'Spark Plate' which was a square
piece of very thin pc board soldered to the case, and used as a terminal
between the switch and the vehicle's electrical system.


Those old Delco systems were still running electromechanical
regulators on generators too - or POSSIBLY electromechanical
regulators on alternators (early delcotrons)
The square wave is low enough in frequency to use with normal
silicon diodes, but at higher frequencies would fail. A standard switch
mode CDC-DC power supply uses square waves without any filtering of the
harmonics. A stepped, or 'quasi' sinewave inverter is only going to
charge the electrolytics at the peak voltage anyway. In this respect,
the square wave is better for the simple diode doubler used in typical
computer power supplies.

Correct.
** Posted from http://www.teranews.com **


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There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.

On Oct 3, 4:34*pm, "Michael A. Terrell"
wrote:

* *If you ever experience a 'load dump' while driving, you'll be trying
to hold on to the steering wheel while tossing a flaming laptop out the
window and breathing toxoc fumes. *I just hope you don't kill anyone
else in the proces.


In the mid 70's I built a load dump simulator for Delco to test the
protection circuit on the new Seville fuel injection computer.
The spec was a 90V, 2 Joule capacitor bank to simulate the energy in a
fully-on alternator field winding when it suddenly is disconnected
from the battery. The worst-case simulation was of corroded cables
jumping around while driving down a bumpy road. My simulator had a
large power supply to recharge the cap bank in about the same time the
field took to return to full current, which they couldn't do with
their lab equipment.

Went to Flint, set it up, they plugged their module in and powered up.
On the third dump it melted the soldered wire off the big Zener clamp
diode, then toasted the module on the fourth as we all rushed to shut
it down. I think that's why they changed to side terminal batteries.

Jim Wilkins
ex automotive test engineer

electronics would be very likely. Plugging a laptop directly into your
cigarette lighter without a regulator in beween will also kill your
laptop. Please keep in mind that vehicle 12 V could very often be as high
as 15 V when the engine is running and would be unfiltered as well as
unregulated.
Steve

I could plug my laptop directly into the 12 volt system and it would not do
squat. it's a 19 volt input on my laptop.


ART

Art Hardy wrote:

electronics would be very likely. Plugging a laptop directly into your
cigarette lighter without a regulator in beween will also kill your
laptop. Please keep in mind that vehicle 12 V could very often be as high
as 15 V when the engine is running and would be unfiltered as well as
unregulated.
Steve

I could plug my laptop directly into the 12 volt system and it would not do
squat. it's a 19 volt input on my laptop.


Yawn. Have it on when you start the engine, and the spike can go up
several hundred volts when the solinoid opens. If you aren't too cheap
to own a scope, look at the 'so called' DC in a 12 VDC system.


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The crazy, and the insane.
The first sign of insanity is denying that you're crazy.

On Sat, 27 Sep 2008 10:45:59 -0400, "Art Hardy" wrote:


electronics would be very likely. Plugging a laptop directly into your
cigarette lighter without a regulator in beween will also kill your
laptop. Please keep in mind that vehicle 12 V could very often be as high
as 15 V when the engine is running and would be unfiltered as well as
unregulated.
Steve

I could plug my laptop directly into the 12 volt system and it would not do
squat. it's a 19 volt input on my laptop.


ART

My 19 volt laptops rin just fine on 12 (or 14.6)

** Posted from http://www.teranews.com **

On Thu, 25 Sep 2008 21:46:03 -0800, "SteveB"
toquerville@zionvistas wrote:

I bought a Trippe Electric 400 watt square wave resistive load only 12v.
inverter at a yard sale. I hooked it up directly to a 12v. battery, and put
in a 110v. test light, the small two prong ones. I flipped the switch, and
couldn't get the test light to come on.

Do I need to hard wire this to the 12v. system? Maybe there wasn't enough
juice in the battery to kick the light on?

I did hook it to a 12v. cigarette plug, and promptly burned out the 5 amp
fuse. I put a 30 amp fuse in there, and it burned that out, too.

What does resistive load only mean? and square wave?

Am I farting in the wind? I need to hook up a laptop in my truck for
business purposes. Should I just go get the cigarette plug inverter they
sell at the computer store?


Got a picture of this you can post?

It sounds like the old one I had in my service van. They
were quite expensive in their day and liked to eat the
output transistors. I believe the 400 watt model used at
least 4 transistors in a push-pull set up. Most likely there
are several shorted out if the fuse blows so readily, but
you might get lucky and there is only one.

A picture would help for making a quick ID. I doubt if it
would be worth putting much money into it. If you are
curious write down the part number on the transistors
(probably something like 2N???) and see what they cost now.
If it is what I'm thinking it is they are mounted along both
sides of the case in between the cooling fins.

--
Leon Fisk
Grand Rapids MI/Zone 5b
Remove no.spam for email

"SteveB" toquerville@zionvistas writes:

I bought a Trippe Electric 400 watt square wave resistive load only 12v.
inverter at a yard sale. I hooked it up directly to a 12v. battery, and put
in a 110v. test light, the small two prong ones. I flipped the switch, and
couldn't get the test light to come on.


You need a fuse, but it's not going to be a few amps.
I agree with the other posts on this area.



If it works, it shouldn't have any problem driving a laptop
charger. While the Triplight has a square wave output, every laptop
supply I have seen is a switcher. What that means is it:

Takes AC in.

Rectifies it to DC and stores it in capacitor.

Takes that DC, uses a ~~100KHz oscillator and makes AC again

Has transformer to make {say} 14VAC

Rectifies THAT to be the DC output you want.

It does all this nonsense because the transformer at 100KHz. is a
fraction of the size of one at 60 Hz. -- less iron, less copper, less
size, less weight and much less money.

So switchers tend to stomach square-wave power far better than say a
small linear ("wall-wart") supply. Those usually run hotter and
have a higher output voltage.


If the Triplight has no output; chances are either the transisters or one
of the feedback caps is toast.

--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

If the Triplight has no output; chances are either the transisters or one
of the feedback caps is toast.


All that said; I agree with the others saying if you want to run JUST a
laptop, buy a DC-DC "Air/Auto" adapter. Most are "Universal" ie you buy
the correct output plug and it programs the voltage you get.

They alas are high-markup items. Igo is one name, Targis another. I am sure
they're more out there.

The exception to the above advice is ^&($%^&% Dell. To force you to buy
Dell-everything; they do some tricks so even if the laptop needs [say]
15.5 volts @2 amps, only the Dell supply will work.

--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

On Sat, 27 Sep 2008 18:55:49 +0000 (UTC), David Lesher
wrote:



If the Triplight has no output; chances are either the transisters or one
of the feedback caps is toast.


All that said; I agree with the others saying if you want to run JUST a
laptop, buy a DC-DC "Air/Auto" adapter. Most are "Universal" ie you buy
the correct output plug and it programs the voltage you get.

They alas are high-markup items. Igo is one name, Targis another. I am sure
they're more out there.

The exception to the above advice is ^&($%^&% Dell. To force you to buy
Dell-everything; they do some tricks so even if the laptop needs [say]
15.5 volts @2 amps, only the Dell supply will work.


With a DELL you are lucky if it works with THEIR power supply.
** Posted from http://www.teranews.com **

On 2008-09-26, SteveB toquerville@zionvistas wrote:
I bought a Trippe Electric 400 watt square wave resistive load only 12v.
inverter at a yard sale. I hooked it up directly to a 12v. battery, and put
in a 110v. test light, the small two prong ones. I flipped the switch, and
couldn't get the test light to come on.

Do I need to hard wire this to the 12v. system? Maybe there wasn't enough
juice in the battery to kick the light on?

What wattage light were you using? Note that an incandescent
lamp tends to draw a *lot* more current when it is first switched on
(lower resistance until it heats up) and thus it might draw too much for
the inverter to start heating.

I did hook it to a 12v. cigarette plug, and promptly burned out the 5 amp
fuse. I put a 30 amp fuse in there, and it burned that out, too.

Well ... assuming 100% efficiency, a 400 Watt load would draw
33.33A from 12 V. You might have perhaps 80% efficiency (if you are
lucky) would would draw 41.66 A.

What does resistive load only mean?

No transformers, motors, TV-sets, computers,, or most other
things you are likely to want to run. You could probably start multiple
smaller lamps, one at a time, to get up near the 400 Watt load limit,
but one 400 W lamp would draw too much current to start off that way.
If you plugged it into the line, and set up switches to switch *very
quickly* from the power line to the inverter you could see whether it
could really support that 400 W load.

and square wave?

It means that unlike the power line, which starts at zero volts,
goes smoothly up to 1.414 times the nominal voltage (so a 120 V line
would peak at 169.6 V, roll over smoothly and start down to duplicate
the behavior below ground (negative voltage) before starting back up to
repeat that pattern until you turn it off. This shape is called a "sine
wave".

This inverter which you have, however, switches very quickly
from -120 V (negative voltage) to the same voltage positive, holds for
1/120th of a second (assuming that it is producing 60 Hz) then drops
very quickly to the same voltage negative, holds and repeats. This kind
of waveform generates all kinds of nasty voltage spikes on the output
side of transformers.

Am I farting in the wind? I need to hook up a laptop in my truck for
business purposes.

A laptop is *not* a resistive load. You will almost certainly
kill it.

Should I just go get the cigarette plug inverter they
sell at the computer store?

Yes -- that should be cheaper than replacing the laptop every
time you connect it and turn it on.

Or maybe you can find a cigarette lighter adaptor to directly
power *that* model of laptop (check what the maker offers), which would
be much more efficient than converting to 120 VAC and then back to the
voltage which the laptop *really* wants.

There are things that this will run -- but don't even *think* of
running a computer from it.

Good Luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
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On 27 Sep 2008 00:42:22 GMT, "DoN. Nichols"
wrote:

On 2008-09-26, SteveB toquerville@zionvistas wrote:
I bought a Trippe Electric 400 watt square wave resistive load only 12v.
inverter at a yard sale. I hooked it up directly to a 12v. battery, and put
in a 110v. test light, the small two prong ones. I flipped the switch, and
couldn't get the test light to come on.

Do I need to hard wire this to the 12v. system? Maybe there wasn't enough
juice in the battery to kick the light on?

What wattage light were you using? Note that an incandescent
lamp tends to draw a *lot* more current when it is first switched on
(lower resistance until it heats up) and thus it might draw too much for
the inverter to start heating.

More likely he was using a neon test light - one of the "pocket clip"
variety which did not put enough of a load on the inverter to allow
it to function. Quite a few of the old tripplite and other "cheap"
inverters were like XT/AT power supplies and would NOT start without a
load.

I did hook it to a 12v. cigarette plug, and promptly burned out the 5 amp
fuse. I put a 30 amp fuse in there, and it burned that out, too.


I'd suspect, unless running a HEAVY load the inverter is toast - one
side of the unit "stuck" on - so when the other side fires, the fuse
blows.

Well ... assuming 100% efficiency, a 400 Watt load would draw
33.33A from 12 V. You might have perhaps 80% efficiency (if you are
lucky) would would draw 41.66 A.

What does resistive load only mean?

No transformers, motors, TV-sets, computers,, or most other
things you are likely to want to run. You could probably start multiple
smaller lamps, one at a time, to get up near the 400 Watt load limit,
but one 400 W lamp would draw too much current to start off that way.
If you plugged it into the line, and set up switches to switch *very
quickly* from the power line to the inverter you could see whether it
could really support that 400 W load.

and square wave?

It means that unlike the power line, which starts at zero volts,
goes smoothly up to 1.414 times the nominal voltage (so a 120 V line
would peak at 169.6 V, roll over smoothly and start down to duplicate
the behavior below ground (negative voltage) before starting back up to
repeat that pattern until you turn it off. This shape is called a "sine
wave".

This inverter which you have, however, switches very quickly
from -120 V (negative voltage) to the same voltage positive, holds for
1/120th of a second (assuming that it is producing 60 Hz) then drops
very quickly to the same voltage negative, holds and repeats. This kind
of waveform generates all kinds of nasty voltage spikes on the output
side of transformers.

Am I farting in the wind? I need to hook up a laptop in my truck for
business purposes.

A laptop is *not* a resistive load. You will almost certainly
kill it.

Should I just go get the cigarette plug inverter they
sell at the computer store?

Yes -- that should be cheaper than replacing the laptop every
time you connect it and turn it on.

Or maybe you can find a cigarette lighter adaptor to directly
power *that* model of laptop (check what the maker offers), which would
be much more efficient than converting to 120 VAC and then back to the
voltage which the laptop *really* wants.

Lots of "universal" laptop converters on the market that provide the
power required and are "self adjusting"

There are things that this will run -- but don't even *think* of
running a computer from it.

Good Luck,
DoN.

** Posted from http://www.teranews.com **

Steve what are you trying to do ?

It sounds like you bought a 12V to 110V inverter power supply.

Being square wave isn't all that good for laptops. It is hard on
transformers. Sine wave is preferred for transformers and 60 cycle regulated.

The square wave type are good for lamps and resistive loads.

If one considers a 100% efficiency box, then 400 / 12 = 33 amps and
the square nature is likely to draw more on the edge currents.

A 40 amp slow blow circuit breaker would be ok.

Resistive load is coffee pot / lamp / toaster - but only lights are
low enough in current to be used. 400 watts is small.

This will NOT work for a laptop in the truck. You need a sine wave unit.

This runs camp lights, Can't run much else.

Martin

Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/


SteveB wrote:
I bought a Trippe Electric 400 watt square wave resistive load only 12v.
inverter at a yard sale. I hooked it up directly to a 12v. battery, and put
in a 110v. test light, the small two prong ones. I flipped the switch, and
couldn't get the test light to come on.

Do I need to hard wire this to the 12v. system? Maybe there wasn't enough
juice in the battery to kick the light on?

I did hook it to a 12v. cigarette plug, and promptly burned out the 5 amp
fuse. I put a 30 amp fuse in there, and it burned that out, too.

What does resistive load only mean? and square wave?

Am I farting in the wind? I need to hook up a laptop in my truck for
business purposes. Should I just go get the cigarette plug inverter they
sell at the computer store?

TIA

Steve



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On Fri, 26 Sep 2008 22:25:42 -0500, "Martin H. Eastburn"
wrote:

Steve what are you trying to do ?

It sounds like you bought a 12V to 110V inverter power supply.

Being square wave isn't all that good for laptops. It is hard on
transformers. Sine wave is preferred for transformers and 60 cycle regulated.

The square wave type are good for lamps and resistive loads.

If one considers a 100% efficiency box, then 400 / 12 = 33 amps and
the square nature is likely to draw more on the edge currents.

A 40 amp slow blow circuit breaker would be ok.

Resistive load is coffee pot / lamp / toaster - but only lights are
low enough in current to be used. 400 watts is small.

This will NOT work for a laptop in the truck. You need a sine wave unit.

This runs camp lights, Can't run much else.

Martin

If the laptop power supply says that it'll accept 110 to 240 VAC (or
something like that, as many do), then its power supply is a
"switcher". These immediately rectify the incoming power to DC so
waveform (sine, square or whatever) is irrelevant to them. As someone
else noted, the resulting DC is then chopped and transformed at high
frequency for economy and compactness.

Or the output voltage is 1x or 2x and regulated to 1x with the dc regulator.

Square wave waveforms saturate transformers and tend to overheat and burn
them out.


Martin
Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/


Don Foreman wrote:
On Fri, 26 Sep 2008 22:25:42 -0500, "Martin H. Eastburn"
wrote:

Steve what are you trying to do ?

It sounds like you bought a 12V to 110V inverter power supply.

Being square wave isn't all that good for laptops. It is hard on
transformers. Sine wave is preferred for transformers and 60 cycle regulated.

The square wave type are good for lamps and resistive loads.

If one considers a 100% efficiency box, then 400 / 12 = 33 amps and
the square nature is likely to draw more on the edge currents.

A 40 amp slow blow circuit breaker would be ok.

Resistive load is coffee pot / lamp / toaster - but only lights are
low enough in current to be used. 400 watts is small.

This will NOT work for a laptop in the truck. You need a sine wave unit.

This runs camp lights, Can't run much else.

Martin

If the laptop power supply says that it'll accept 110 to 240 VAC (or
something like that, as many do), then its power supply is a
"switcher". These immediately rectify the incoming power to DC so
waveform (sine, square or whatever) is irrelevant to them. As someone
else noted, the resulting DC is then chopped and transformed at high
frequency for economy and compactness.


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On Sat, 27 Sep 2008 21:37:16 -0500, "Martin H. Eastburn"
wrote:

Or the output voltage is 1x or 2x and regulated to 1x with the dc regulator.

Square wave waveforms saturate transformers and tend to overheat and burn
them out.

Only if the transformer isn't designed to handle squarewaves. In a
switcher, whatever voltage is supplied is rectified before use
anyway so the supply waveform is about immaterial. The DC is then
converted to high-freq AC, of waveform suitable for the small HF
transformers designed to work in that particular circuit. Some are
squarewave, others (as in resonant converters) aren't.

I'm not current on power supply design and technology anymore, but I
designed a bunch of switchmode squarewave ferrite-core transformers
some years ago. Ain't no big deal, they don't saturate if they're
designed for the job.

I did hook it to a 12v. cigarette plug, and promptly burned out the 5 amp
fuse. I put a 30 amp fuse in there, and it burned that out, too.


Is it burning out the fuse with no load? If it is the inverter is no good.
I suggest buying a 12 volt adapter for your laptop.
ART

Art Hardy wrote:


I did hook it to a 12v. cigarette plug, and promptly burned out the 5 amp
fuse. I put a 30 amp fuse in there, and it burned that out, too.


Is it burning out the fuse with no load? If it is the inverter is no good.
I suggest buying a 12 volt adapter for your laptop.


You know less about inverters than you do about laptops. There is a
minimum current requirement for the inverter, and it goes up when it is
used with a load. When first turned on, the large electrolytics need to
charge, and draw a large current spike.


--
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aioe.org, Goggle Groups, and Web TV users must request to be white
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your account: http://www.usenettools.net/ISP.htm


There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.

try a real light bulb - your neon bulb doesn't put a load on the unit until
the gas ionizes. I don't understand the "hooked it up to a 12v cigarette
plug..." statement - if you mean you hooked the 115VAC output to a 12V cig
ligher load, that wasn't a good idea. If you mean that you hooked the 12V
input to a 12V source, then how the heck did you test it with the battery?

please provide a more systematic statement of what you tested and exactly
what you did. And please test it with a 15 watt light bulb, or a 100 watt
light bulb.

Note that 400 watts at 12V is over 30 amps

"SteveB" toquerville@zionvistas wrote in message
news
I bought a Trippe Electric 400 watt square wave resistive load only 12v.
inverter at a yard sale. I hooked it up directly to a 12v. battery, and
put in a 110v. test light, the small two prong ones. I flipped the switch,
and couldn't get the test light to come on.

Do I need to hard wire this to the 12v. system? Maybe there wasn't enough
juice in the battery to kick the light on?

I did hook it to a 12v. cigarette plug, and promptly burned out the 5 amp
fuse. I put a 30 amp fuse in there, and it burned that out, too.

What does resistive load only mean? and square wave?

Am I farting in the wind? I need to hook up a laptop in my truck for
business purposes. Should I just go get the cigarette plug inverter they
sell at the computer store?

TIA

Steve

--
"...the man who really counts in the world is the doer, not the mere
critic-the man who actually does the work, even if roughly and
imperfectly, not the man who only talks or writes about how it ought to be
done." Theodore Roosevelt 1891



** Posted from http://www.teranews.com **

"William Noble" wrote in message
...
try a real light bulb - your neon bulb doesn't put a load on the unit
until the gas ionizes. I don't understand the "hooked it up to a 12v
cigarette plug..." statement - if you mean you hooked the 115VAC output to
a 12V cig ligher load, that wasn't a good idea. If you mean that you
hooked the 12V input to a 12V source, then how the heck did you test it
with the battery?

please provide a more systematic statement of what you tested and exactly
what you did. And please test it with a 15 watt light bulb, or a 100 watt
light bulb.

Note that 400 watts at 12V is over 30 amps

"SteveB" toquerville@zionvistas wrote in message
news
I bought a Trippe Electric 400 watt square wave resistive load only 12v.
inverter at a yard sale. I hooked it up directly to a 12v. battery, and
put in a 110v. test light, the small two prong ones. I flipped the
switch, and couldn't get the test light to come on.

Do I need to hard wire this to the 12v. system? Maybe there wasn't
enough juice in the battery to kick the light on?

I did hook it to a 12v. cigarette plug, and promptly burned out the 5 amp
fuse. I put a 30 amp fuse in there, and it burned that out, too.

What does resistive load only mean? and square wave?

Am I farting in the wind? I need to hook up a laptop in my truck for
business purposes. Should I just go get the cigarette plug inverter they
sell at the computer store?

TIA

Steve

--
"...the man who really counts in the world is the doer, not the mere
critic-the man who actually does the work, even if roughly and
imperfectly, not the man who only talks or writes about how it ought to
be done." Theodore Roosevelt 1891



** Posted from http://www.teranews.com **

I bought a 12v. cigarette male plug. I put two connectors on it to screw to
the lugs on the inverter. Put the two wires in correct polarity onto the
inverter, then plugged in the cigarette lighter.

Since then, I have found a Coleman inverter that I bought. Main difference
is that the cigarette lighter insert is unfused, but there is a fuse in the
inverter.

Will try that as soon as I have some time. Still not sure if the original
Trippe is functional or not. Will try it with the unfused pigtail from the
coleman, and a lightbulb load.

When trying the original configuration, I DID try it with the computer, but
it did not activate the computer.

Steve

On Sep 26, 1:46*am, "SteveB" toquerville@zionvistas wrote:
I bought a Trippe Electric 400 watt square wave resistive load only 12v.
inverter at a yard sale. *I hooked it up directly to a 12v. battery, and put
in a 110v. test light, the small two prong ones. *I flipped the switch, and
couldn't get the test light to come on.

Do I need to hard wire this to the 12v. system? *Maybe there wasn't enough
juice in the battery to kick the light on?

I did hook it to a 12v. cigarette plug, and promptly burned out the 5 amp
fuse. *I put a 30 amp fuse in there, and it burned that out, too.

What does resistive load only mean? *and square wave?

Am I farting in the wind? *I need to hook up a laptop in my truck for
business purposes. *Should I just go get the cigarette plug inverter they
sell at the computer store?

TIA

Steve


Square wave is No Good for laptops. Resistive load means just that,
incandescent lights and resistive heaters, not motors and definitely
no electronics. Don't blow out a $100 laptop power brick using the
wrong inverter. If you shop around, you can get a decent 70-100 watt
travel inverter with a modified sine wave for about $20. I picked up
a Coleman brand one from Big Lots for that just recently. Modified
sine wave output is close enough for running most electronic equipment
these days. The travel inverters usually have battery protection
circuitry, if the car battery voltage gets too low, they shut off so
you can at least start the vehicle.

Used inverters are a crap shoot. Sounds like yours is shorted.

Stan