Hello, I have quite a lot of devices that works at 12 or 5V (router, eth. switch, raspberry, etc.). Everyone has is own AC/DC power supply.
I'd like to put all the devices under an UPS, but it seems stupid to do AC- DC-AC-DC.
So the question is do you know if a UPS with a regulated 12V output (and AC input) exists?
The only things I found are UPS with unregulated 12V output (means that the output is the same voltage the battery sees), or this: http://www.mini-box .com/OpenUPS, but is has DC input, so I need to add a battery and a AC/DC p ower supply, so at the end is quite expensive.
Or I can buy a SLA battery, add a stupid off the shelf battery charger, and some DCDC from ebay and go with it (if it works).
, raspberry, etc.). Everyone has is own AC/DC power supply.
C-DC-AC-DC.
AC input) exists?
he output is the same voltage the battery sees), or this: http://www.mini-b ox.com/OpenUPS, but is has DC input, so I need to add a battery and a AC/DC power supply, so at the end is quite expensive.
nd some DCDC from ebay and go with it (if it works).
I have the same situation; Modem Router wants 9 VDC, Camera 5 VDC, Speakers 12 VDC, and 4 External Hard Drives want 12 VDC.
I bought a bunch of DC/DC step down converters (buck converters) and wired them to the appropriate barrel connectors for the 5 and 9 volt devices. They are adjustable and set with a pot - then I shrink some large heat shrink tubing over them to keep them from shorting and wire them in-line to the lower volt devices.
The whole shebang is powered by a surplus 12 VDC 4 amp table top power supply (lying on the floor) with a box holding 6 - 1500 farad ultra caps (with a fuse since they are capable of some serious discharge current)
I put a few extra barrel connectors on it so I can tinker with devices from time to time, and wired a small 3 digit voltmeter to it so I can easily check the connectors etc and shrunk some clear heat shrink on the voltmeter and it's connector. (very handy for checking all those barrel connectors and step down modules)
Frees up 8 wall wart power supplies, and will keep the modem/wifi up for 1/2 hour (longer if I unplug the other stuff) in a power failure, so I can still use my laptop and tablets.
The buck converters are easy to use, and can be used just like three terminal regulators.
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They can be had from under $2 each
Voltmeter
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Also for less than $2
Barrel connectors (get ones with pre-served leads or screw terminals - easier to use and some of them melt before the solder does) can be had on Ebay as well as super caps or ultra caps.
With using ultra caps you don't need a charging voltage of 13+ volts that a lead-acid battery needs, and the attendant steering diodes etc. to make a 12 volt ups system.
There are power supplies with built in 12 battery chargers too, mpja.com has one for $20, but it only supplies 1.5 amps and that's not enough for all the stuff I hang on my ups system.
interesting. But quite expensive: a 1500F ultracap on digikey is around 60$ or you meant 1550 mF?
own-Power-Supply-Module
-Module
yes, already saw them
I found a power supply with battery backup for 20$ expedited on aliexpress, but the output must be around 13.8V otherwise the battery is not charged : / But at the end if I can't find any other solution a DCDC that you linked to output a steady 12V...
No, I mean Farads. They can, and have, started my truck.
ULTRACAPACITOR 1500 FARADS CAT# UCP-1500 $16.50 each allelectronics.com
They do make power supplies that have two outputs, one for the battery and one for the load with steering diodes to power the load when the power goes out (or in other words, a 12 VDC ups system) but when all is said and done, the super caps, while expensive, do the job just fine, and won't (shouldn't) have to be replaced every 5 years or so.
When I bought my caps they were priced at $15 each, but I did have to buy some nuts since they didn't supply them with the caps. I made a plywood box and bussed them with aluminum rectangular bus bars, and drilled and tapped them so I could put on some screw to post battery adapters for starting the truck. For balancing the charge I rigged the yellow led and rectifier diode circuit that's on line, along with a pair of 2.5 volt zener diodes per cap for extra protection. The active balancing circuit isn't terribly expensive but I wanted to get up and running with stuff I had on hand.
I decided to go the AC-DC-AC-DC route, but just once (per voltage). Using a DIN-rail 12v ps with 5A output:
Screw terms let me wire as many outputs as my heart desires and DIN term blocks give me unlimited expansion. DIN-rail mounts to bottom of my desk, all wires snake up and over the desk to their destinations. Labels at the barrels identify voltage &connected device to avoid mixups. AC input plugs into my UPS.
, raspberry, etc.). Everyone has is own AC/DC power supply.
C-DC-AC-DC.
AC input) exists?
he output is the same voltage the battery sees), or this: http://www.mini-b ox.com/OpenUPS, but is has DC input, so I need to add a battery and a AC/DC power supply, so at the end is quite expensive.
nd some DCDC from ebay and go with it (if it works).
I've used one by Belkin to power a monitor network: BELKIN BU3DC001-12V
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