# Anyone ever build a DC to AC inverter ? Needs to run on 32v DC

#### 32Vwasbetteronboats

Feb 18, 2017
80

I want to try this, the 32 volt systems on older boats is better then 12v they use today except that buying a 32v inverter is very expensive . 32V is better cause I don't need run thick ass wire to run things ! Stupid car industry screwing up boats with it's 12v nonsense.

Would modifying a 12v DC to 110 AC inverter to run on 32v be a better option then starting from scratch ?

Maybe I could rewind a microwave transformer and use it to make a 12v dc inverter operate on 32V.

#### (*steve*)

##### ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
The first change would be to use an approx 60V CT transformer. That may be hard to find.

#### (*steve*)

##### ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
Also, you'll note that the circuit you have used PNP transistors. If you do your research you'll find it was designed for germanium transistors.

Whilst silicon transistors are better in many respects, the BE breakdown voltage is one area where they are not. It is quite possible that if you build this, it will be susceptible to failure caused by failure of the BE junction. Placing diodes in series with the connection to the base can largely fix this.

Another issue is that this circuit has no control of frequency nor any regulation. The frequency and output voltage is likely to vary quite significantly with load.

#### 32Vwasbetteronboats

Feb 18, 2017
80
The first change would be to use an approx 60V CT transformer. That may be hard to find.

So changing just the output transformer on a 12v inverter could make it work on 32v ?

After I made this post I was thinking that it wouldn't work cause the 32v would change the math on every thing behind the transformer.

#### duke37

Jan 9, 2011
5,364
What will the 120V output be used for? What frequency is wanted? Will a square wave do?

You will need some high voltage transitors. I would go for an oscillator to set the frequency and FETs for efficiency. The transformer should run unsaturated.

#### (*steve*)

##### ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
After I made this post I was thinking that it wouldn't work cause the 32v would change the math on every thing behind the transformer.

Yes that's true. My suggestion that the transformer would be the first thing was based on the view that with this circuit it would be a complete no-go without it. If you can find a transformer then you will need to do more work to make the test of the circuit work at the higher voltage.

#### Aplicant

Nov 16, 2016
18
Try this

But i am not sure that it works or not
I am not a good electronic student

#### 73's de Edd

Aug 21, 2015
3,634
The MOST important spec I have not seen yet is the WATTAGE that you are expecting on that 120V secondary.
A table lamp or . . . . forbid . . . a refrigerator or microwave . . . . .dream on.

#### 32Vwasbetteronboats

Feb 18, 2017
80
I have my blown Newmar 32v to 300 W 115 square wave right in front of me now.

Not that many parts inside I honestly don't know where to begin diagnosing it.

Running a flat screen and laptop, added a 100 watt incandescent lamp and that was it, something blew.

Find the cord for my camera and I will upload a photo, can't find one Google images.

Only 300 watts but its heavy , has a transformer in the middle slightly bigger then inside a microwave oven.

I have 12v to 400w 115 it weighs a third as much.

EDIT , I found an online photo

I did not screw up polarity, it was already installed and worked.

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#### AnalogEL

Feb 21, 2017
11
Incandescent lamps are very low resistance cold, maybe your inverter felt shorted.

#### 32Vwasbetteronboats

Feb 18, 2017
80
Try this
View attachment 32135
But i am not sure that it works or not
I am not a good electronic student

Thanks,

I learn best by experimenting and blowing stuff up, I like this stuff but have alot to learn if I want to be able to play at this level.

Last edited:

#### 32Vwasbetteronboats

Feb 18, 2017
80
Incandescent lamps are very low resistance cold, maybe your inverter felt shorted.

Before that filament gets hot it puts a heavy load, exactly.

I wonder what fails from a short. ?

#### 73's de Edd

Aug 21, 2015
3,634
Unplug all loads and then let the lamp be the FIRST unit added and 10 seconds to fully warm up . . . then add the other 2 loads to see if it will run all of hem. With what items you have given as loads seems like 300w is met or exceeded.

#### 32Vwasbetteronboats

Feb 18, 2017
80
Unplug all loads and then let the lamp be the FIRST unit added and 10 seconds to fully warm up . . . then add the other 2 loads to see if it will run all of hem. With what items you have given as loads seems like 300w is met or exceeded.

OK tomorrow I will reconnect it, I used that 32v line to power this

Clearance 57% Off
$127.77 Original$299.99 Capable of running off a wide range of voltages (12V-54V DC)...
I should buy another, I think its on sale cause its not 'sleek' looking enough for people.

Oops , going off topic, I will try that and poke around with my meter when I power it up.

#### (*steve*)

##### ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
Changing to LED illumination and running that from your 32V source will be way more efficient too.

#### 73's de Edd

Aug 21, 2015
3,634
Another consideration . . . .of potential undesirability, which you can ascertain, is if the physically linear positioned LEDs puts out a STRIP of light . . . .sort of undesirable.
Or if the combination of the individual LEDs are individually offset to produce a tight square pattern thereby, a more desirable SPOT cluster.

At different times, I have placed an ~ 1 in diameter convex lens in front of a high intensity white LED to decrease its dispersion angle and increase its light intensity in making a flashlight / torch.
You only have to do this once, to realize that at one focus spacing, that you will get a projected image of the whole LED body proper.
HIGHLY undesirable, instead you want to stop short of that focused apex , where you will get a bright white circle.

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#### 32Vwasbetteronboats

Feb 18, 2017
80
At different times, I have placed an ~ 1 in diameter convex lens in front of a high intensity white LED to decrease its dispersion angle and increase its light intensity in making a flashlight / torch..

Get me started playing with light again

I feel bad already cause I recently saw a projection TV out for the trash and didn't fetch the Fresnel lens and the glass ones inside. Its getting rare to see them on the curb.

The next project I do should be the solar furnace, just thinking I could burn images of the upcoming solar eclipse into wood or other materials.

Monday

August 21 Solar eclipse of August 21, 2017

. Ozzy Osbourne has signed on to headline Moonstock, a unique music festival set to coincide with a total solar eclipse. Southern Illinois has been determined as the spot that will have the longest duration of the rare total solar eclipse and festival organizers have invited Osbourne to “bark at the moon” with his set coinciding with the eclipse taking place.

I MUST go to this , no clouds !!

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