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shineybullet 10-18-2015 06:29 PM

Univolt why so heavy ?
 
I just removed the old univolt in my 1972 overlander and when I went to lift it out it really made me grunt, it must weigh over 60 lbs , I was wondering what's inside one of these old Bruts that make them so heavy ? I'm really curious 🇨🇱

0557 10-18-2015 06:32 PM

Because of the transformer that's in it for conversion

idroba 10-18-2015 07:31 PM

Prior to switching power supplies about the only way to convert voltage was with a transformer. In this case a big heavy one.

Electronics changed all of that, but transformer systems are still simple, very reliable and easy to understand. But the old Univolt is simply obsolete as a converter/charger system.

AWCHIEF 10-18-2015 08:19 PM

Good old solid American made steel and iron. Almost bullet proof and make great boat anchors.

DryFly 10-18-2015 09:34 PM

The reason it's so heavy is because it's got A LOT of copper for the windings. Take it apart and you'll see. Most of it can be recycled.

nrgtrakr 10-18-2015 10:22 PM

... wondering outloud why I didn't remove ours when I had the bathroom partially disassembled to replace the shower valve and plumbing ...

barts 10-18-2015 10:24 PM

The size of a transformer is inversely related to the frequency for which it's designed... so a switching mode power supply that runs at 20+khz will have a much smaller transformer than a 60hz model.

In the end, the ferroresonant Univolts are prob. more reliable than the
switching supplies that have replaced them - but the new units are much cheaper, more efficient and quieter. The new systems also provide for temperature adjusted charging voltages, and the three-stage systems won't cook your batteries, either.

- Bart

cwf 10-18-2015 10:40 PM

1 Attachment(s)
They are far lighter when you let out the "magic smoke"!

shineybullet 10-18-2015 11:28 PM

Quote:

Originally Posted by barts (Post 1698750)
The size of a transformer is inversely related to the frequency for which it's designed... so a switching mode power supply that runs at 20+khz will have a much smaller transformer than a 60hz model.

In the end, the ferroresonant Univolts are prob. more reliable than the
switching supplies that have replaced them - but the new units are much cheaper, more efficient and quieter. The new systems also provide for temperature adjusted charging voltages, and the three-stage systems won't cook your batteries, either.

- Bart

It looks like mine must have quit working years ago,some pasr owner cut off its power cord to the Uni volt and wired a small battery charger in its place I'm putting in a 45 amp smart converter in its place with 2 huge 12 volt yellow top batteries :brows:

alantbird 10-19-2015 12:01 PM

1st one I replaced was in my 77 ambassador (in1999) and it was suddenly sooo quiet!

Royce 10-19-2015 01:13 PM

I gave mine to a local HAM radio operator. He changed it to an oil filled unit and is happy to give it a new home. I was happy to get the 75 or so lbs out and a new quiet converter in.

StarckMad 10-19-2015 04:11 PM

NRGTRKR: thanks for the confirming word. I still have our bathroom and closet apart for plumbing replacement. Might as well jump into that too!

nrgtrakr 10-19-2015 05:32 PM

Hahahaa!!!
Anytime ...
I wonder if it will fit through the battery box door if the battery compartment liner is removed?
I like our AS, but wonder about space utilization at times.

Jammer 10-19-2015 05:51 PM

I believe that the early univolts were ferroresonant, which added to their weight.

Ferroresonant transformers provide a measure of passive voltage regulation, and were a reasonably common design choice before high power MOS devices were available.


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