| RobPhill33 |
I thought that it would be easy to build a power supply for anodizing aluminum, as seen here.http://www.caswellplating.com/supplies/rect.htm
I want to make the 12V @ 50A PS. However, I can not seem to find the right transformer for the job. Plitron or Hammond don't have one tha fit the specs (600 - 700 VA, 9V Sec), nor do I need that quality for this. Does anyone know where to find this transformer? |
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| Thomas |
| Why not just parallel some smaller transformers to get the VA rating you want? |
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| RobPhill33 |
| It costs substantially more money to by 5 @ 120VA than 1 @ 750VA. |
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| Da5id4Vz |
| How bout a car battery kept under charge with a trickle charger, kind of like the phone company does. It would have plenty of current, and not too expensive. You’ll want to keep it well ventilated and keep a fuse in series with the plating tank. Shorting 12V at 50+ amps can be spectacular and quite dangerous if the battery has vented any hydrogen gas. A boat battery and case from a marine supply store with one of those nice plastic cases would be ideal. If you want to stay on budget, I think most auto junkyards will sell a used battery for a couple of bucks. You could put it in an old pick nick cooler from a yard sale. Put some vent holes in the cooler, you wouldn’t want it to go Hindenburg on you. |
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| RobPhill33 |
| It would be cheaper wouldn't it. Can you find a trickle charger at a local store? How about a full on battery charger/starter, you wouldn't need a battery. |
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| Da5id4Vz |
I don’t know that an affordable charger starter will be rated to deliver 50 amps for more than a min or two at a time.
I'm assuming that anodizing requires that things be pickled for quite a while.
Brings up another issue about the battery. I think batteries car batteries can deliver about 200 amps (please correct me here), but for how long? Assuming that the anodizing would have its current decrees the longer the process is taking place, you’d likely get a fair amount of time out of one battery, but then again it might take several in parallel to keep up with the reaction.
If the neighbors don’t mind the Junk Yard Wars look, you could charge the cells with a windmill made from an old alternator.
I think the charger I just bought will deliver up to 5 amps trickle. Good for chemistry experiments, but likely not good enough to anodize a large panel. |
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| RobPhill33 |
| I just looked up some battery chargers and you're right, not enough juice. The power supply may be the way to go. |
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| pinkmouse |
I was experimenting with anodising the other week, and I had great success using just a car battery on its own. I was just mucking around with some bits of plate around 6" square and 1/8" thick, and it took around 30 min. to get a decent finish.
I suspect if you were doing heatsinks for a Pass Lab project it would be a bit underpowered, but for a case front or similar you should have no problem. |
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| RobPhill33 |
| I will have to anodize large pieces (360 inch sq). That requires about 25A continuously so I need a substantial PS. |
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| pinkmouse |
| quote: | Originally posted by RobPhill33
I will have to anodize large pieces (360 inch sq). That requires about 25A continuously so I need a substantial PS. |
It's a shame you are in Canada, I know where there are some surplus single ended 12V 30A transformers in the UK that were used at Motor Shows for powering cars used as display exhibits...:( |
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| Circlotron |
| Series up two or three 5 volts outputs from some old pc power supplies? These will usually supply lots of amps, especially if they don't have to draw in warm air from the pc case. You may have to put a bit of load on the unused rails to make the psu's work properly. Regulate the current with a couple of paralleled car light globes in line with the dc. Flip the fan over inside the psu box so they blow through instead of suck through and then you could even position the boxes so they blow any vapours away too! :) |
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| RobPhill33 |
| I am going to by 12 - 50VA @ 13V x 2 and parallel. I think that should work, please correct me if I have forgotten something. |
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| Philo |
| I have been looking into home anodizing as well. FMU, a couple of used car batteries in parallel are sufficient to provide the current to do most hot anodizing in a storage bin container. An old style manual charger the size they use on heavy equip, trucks and buses will work without overheating the transformer, but the PepBoy's types are automatic and under-rated. When I get back to work tomorrow I will post a link that has info on some alternatives to buying the expensive PSUs. |
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| MRehorst |
I frerquently see 5V up to 120A switching power supplies at swap meets selling for under $20. Hard to imagine you ccould build anything close to this for less...
MR |
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| Da5id4Vz |
Some switching power supplies need to see some load on them to keep them from taking off buring up. Though I dont think that would be too much of an issue fo this aplication.
I sumbed across this while following another thread:
http://www.surplussales.com/Miscell.../Misc-main.html
(LMP)-ALC-X-36LC
Mil-spec DUAL-LITE Emergency Light is perfect for most situations were power failure lighting is required. This is the largest model of the series. It will supply 15 amps of 6vdc for 1.5 hours! Two 360 degrees rotatable 25 watt sealed beam lamps. Built in battery charging system keeps 6v battery topped off and ready to go. AC supply of 115v or 277v @ 15-75 watts.
Requires 6v battery 7-1/2" deep x 10" wide x 10" high... or smaller. Not included. Overall dimensions 8" deep x 14" wide x 17-1/2" high. All enclosed except front battery inspection hole as shown.
Units are new, boxed, never used.
$50 each
$40 (4 or more) |
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| Havoc |
Check out stores for lighting supplies. You can find big transfos for halogen lighting. They are typical 12V.
Other sources are second hand measurement instrument shops. There you could find Farnell power supplies. They made 60V/50A supplies. Heavy (+25kg), regulated (volt and amp) and they can take out your fuses when you start them!
Take a better look in car supply shops. There are high current chargers, I have seem models up to 100A.
Maybe welding equipment? |
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| sangram |
Hi
RobPhil, can you tell me where I can learn more about anodizing and how it can be done at home?
Eager to learn, good access to lots of good 12V 26 AH batteries, and lots of really bad aluminium for front panels... |
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