lol i know sounds abit strange, but if i was to get a power inverter that took power from the battery and had ur typical household plug outlet, can this be flipped so that household power would supply and you would get 12v dc output? OR would i blow some sh!t up doing this? lol
Cheers :).

u cant use a 240V to 12V inverter backwards. it would just start smoking.

alternativly you can go to jaycar or d|ckheads. and get something like this.

http://www.jaycar.com.au/productView.asp?ID=MP3035&CATID=&keywords=12V+power+supply&SPECIAL=&form=KEYWORD&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=

i build up a 12v invertor, its sitting in my cupboard :D

also the reason its called an Inverter is because it changes AC to DC.
if it just changes the voltage that means its a Transformer.

so im gathering your want to change House power ( 240VAC ) to 12VDC

Yeh was just a thought, i figured the thing would start smoking if i swapped them round, just wasn't sure.
Would be cool to play my car stereo at parties and stuff :P.

i looked into converting my car so i could plug it into mains power awhile back

was going to cost $1000+ easy for the mod so i never worried about it ... sounded like a big job and a major headache

Those small 12V-240V inverters only work 1 way, made for cars.

Depending on how much you want to spend... there are larger (not for car use) units that also incorporate a battery charger - keep them plugged into the wall and they'll keep the 12V battery charged. When the 240V is disconnected the battery juices the 240V outputs.



Yeh was just a thought, i figured the thing would start smoking if i swapped them round, just wasn't sure.
Would be cool to play my car stereo at parties and stuff :P.

Get a 13.8V power supply, commonly used for powering CB radios on your workbench.

Can get them in various sizes from Electus etc, I got one rated at 11A and it works great running 12V gadgets at home. Can get larger units offering 15A, 25A, 40A etc etc... just a matter of how much juice you need.

Alternately, the 'hack' way is to run the gear off a 12V battery and keep a 4A charger on the battery at all times to keep it topped up.

from memory GME do a 4,7,11 maybe a 20 and a 30 amp 240v - 12v source


4amp retails $74
11amp i think is around $198
30amp retails for $493

i'd have to check what the others are ... but if anyone wants 1 i can do a better deal for AMC members

from memory GME do a 4,7,11 maybe a 20 and a 30 amp 240v - 12v source


4amp retails $74
11amp i think is around $198
30amp retails for $493

i'd have to check what the others are ... but if anyone wants 1 i can do a better deal for AMC members
hey hey, I have the GME 11A. Solid old-skool Oz-built unit!

btw those "ratings" are for 50% load, ie don't expect 11A continuous.

I run a draw of ~5A off it, works great.

But running 2x 5A devices off it, the voltage starts dropping :doubt:
and the heatsink gets very hot... so mine's modded with rear fan,
dual banana output terminals out front, IEC powercord, changed LED.

Nothing stays 'stock' very long... :badgrin:

If you want a cheap high current 12 DC power source, you cannot go past modified PC power supplies!

You can modify them so that they independently regulate (matched with high current diodes) or so that you have one master and several slaves. I did this ages ago (1 master, many slaves) to get ~200A at 13.8V. Only downside was the massive sag it dropped across the mains due to inrush current.

Cheers
Heath Young

I never thought of a pc power supply, but i wouldn't think they'd be able to supply much current? I'm guessing thats why you wired them up as master -> slaves, but just how many did you need to pull 200A lol?

JUST GO TO SUPERCHEAP AND BUY A BATTERY CHARGER, EASY CHEAP AND EFFECTIVE :bowrofl:

i too have used a pc power supply for a 12volt source, great stuff after buying new computer and selling most of the old ones parts, kept the power supply and simply removed the cover modded the wiring and hey... got myself a very powerful 12 volt source with a safety switch for reverse connection and all, new its probably not worth it about $40 or so but if you can scab one of a mate or something it would be great

If you want a cheap high current 12 DC power source, you cannot go past modified PC power supplies!

You can modify them so that they independently regulate (matched with high current diodes) or so that you have one master and several slaves. I did this ages ago (1 master, many slaves) to get ~200A at 13.8V. Only downside was the massive sag it dropped across the mains due to inrush current.
Must be a pretty fancy PSU you modified there Heath.
Usually the yumcha ones aren't too flash... barely 11.5-12.0V when sucking 10A. :doubt:

Modern "ATX" style PSUs are a little harder to mod (need to jumper the mobo cord)
so the old style "AT" PSUs are preferred if you can still find them.
Switchmode power supplies like to be loaded equally across all channels too,
the dodgy way is to run lightbulbs or big resistors as a dummy load.

All this hacking makes the PSU unApproved too. :hand:

BIG DISCLAIMER:- don't anyone be mucking around with 240V mains voltage
if you don't know what you're doing. Life is in your own hands.

if you are interested in using a PSU the green and black wires (cant remember the pin numbers, can look if you want) that need to be bridged to have the PSU turn on when 240AC is supplied

if your to lazy :P i can swing you one of mine, thats if your in melb

on ebay you can buy big amperage power supplies, but the larger you get the more it costs. So what i did many many years ago (when i had a pair of car power amplifiers) was a car battery, hooked up to a 4amp battery charger that was on all the time. Bought this from DSE (it has automatic charge cutoff so it only charges when it needs to). The battery held charge for many many hours of full power from the amps.
I had this setup for i would dare say a couple of yrs (until i woke up to myself and bought some real rotel power amplifiers 180watt rms into 8 ohms ;) ooohh yeh)