I had an idea and I want to know if its worth pursuing.

A UPS that will run a 3D printer for more than 10 minutes in a power outage are really pricey.

They also are very inefficient. UPS's take 110 ac and convert it to 12v or 36v dc to charge a set of battery's, then convert that back to 110 for use in anything that uses AC. This has relatively low efficiency. You are using more power with a UPS than you would plugged directly into a wall.

Most 3D printers run on 12v dc, converting from 110v ac So why so many conversions. With a UPS you are doing 110v ac - 12v dc - 110v ac - 12v dc. No power conversion is 100% efficient.

What I propose is a simple circuit that hooks in between the power supply and the printer with some cheap hobby batterys. The board would have to have a charge circuit to charge the batterys and a fail over circuit to switch from the power supply to the battery in case of power outage. This could be done with LiPo batterys but some precautions would have to be taken to prevent overcharging and over depleting.

Tell me what you think. Any input is appreciated. If someone has already done it please link me. lol

Edited 1 time(s). Last edit at 04/20/2013 01:28PM by hendo420.

Six of one, half dozen of the other. I guess it depends what part of the world you live in, but power outages are not a big enough concern, IMO, to warrant such a solution.

That's not to say that it is not entierly without merit. Being able to drive a printer from a portable power source would definately find many uses.

UPSes don't typically make use of the battery when AC power is supplied. It has a charging and switchover circuits that allow it to maintain power out during an outage, without dropping supply, and to keep the battery at an optimal level.

It has been done... [e.molioner.dk]
[www.mini-box.com]

The alternative is a battery backed power supply, It float charges the battery (a car battery would do well) and produces a regulated 12V output.

Banjer Wrote:
-------------------------------------------------------
> It has been done...
> [e.molioner.dk]
> [www.mini-box.com]
> PS-system-battery-backup-system


Awesome, that looks pretty simple too.

I live about 15 miles from the nearest town and our power goes out about once every 3 months or so, sometimes for a minute, sometimes for hours. Usually caused by a big storm. I run the printer off of my laptop so I don't have to worry about the computer losing power. I also live in an old farm house with bad wiring so we blow breakers more often than most.

The printrbot Jr. Is being ran solely off of lipo batteries by a lot of its users. They can run it long enouph for full prints. If your interested in learning and talking to the people that do it you can go to printrbottalk.com and chat with them in the forums.

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If you want to keep mains stuff runnig as well then check out Dans data on UPS upgrades
Some good discussion there.

Cheers,
Robin.