I agree that a 200 watt power supply would be ideal, but 63 watts is hardly `next to useless'. Assuming that his power supply can put out
5 amps at 12 volts, he should be able to charge up to 8 cell packs at
4 amps, or 4 cell LiPo at 2.5 amps (the max that the Triton will do with LiPo, I think) ...
I fly a lot of electrics, and I don't have any packs that are large enough that I'd need more than 5 amps input into my Triton to charge them. I doubt I'm unique in this.
(Of course, I do have two Tritons and an Astroflight 110D. To use all three at once, I'd definately need more power, but for just one of them, 5 amps is usually enough.)
| > it has 12volts ( acka tester with new 9volt) and a 5 volt feed | | While these older supplies generate what appears to be a good 12V try | measuring it under load. You might find it drops very quickly.
Perhaps, but even if it can only do 4 amps, it's still useful.
| > it has an old hard disk for load ( possibly replaced by a 12volt car | > light later) and a 30 amp illuminated switch for control. | | Forget the car light (assuming you mean headlight) any decent headlight will | draw more power than unit can supply.
`Car light' covers a lot of ground, and your assumption is probably incorrect. My power supplies use a 12 volt car light (think brake light) on the 5 volt line to make the power supply happy. Works great.
| > I'm using it for foam cutting now and may use the triton on it if it | > has sutable amps... | | 63W divided by 12V = approx 5Amps. Totally unsuitable, particularly once you | add that load to get it running.
I disagree ...
| Imagine your charger can charge a max of 24 cells (as I believe the Triton | does). | | 25cells x 1.2V nominal per battery x 0.5W for a basic charge rate = | approx 15Amps draw | (note I'm simplifying here for those electrical experts out there)
The Triton will draw up to 13 amps when charging the right battery at it's highest rate. But most people don't have those batteries, or could just slow the charge rate down if they needed to. Certainly, the Triton will let you know immediately and loudly if the voltage drops low enough to not make it happy anymore, and then you just lower your charge rate.
Also note that when charging, it's more up to 1.5 - 1.6 volts per cell that you need to put into the cell to charge it at a high rate. Possibly even a bit higher if it has a high internal resistance.
More appropriate math would be 24 cells * 1.6 volts * 5 amps / 12 volts. That works out to 16 amps, plus you'd have to add some percentage to cover the not 100% efficient charging circuits (especially the circuit that converts 12 volts to 36 or so volts), but I'm pretty sure the Triton slows down it's charge rate greatly when you get that many cells on it.
But either way, if you don't need to charge huge packs, 5 amps input will probably fit most of your needs with a single Triton.
| 2. Fit some decent wire wound resistors to the 5V side to generate | sufficient load that the 12V side comes upto 12Vs. | 3. Fit the resistors with a suitable heatsink and mount them securely.
Using automobile brake lights, and you won't even need heat sinks, and they're cheaper and let you know that it's on.
| 5. Fit a lamp to the 12V side (The light in the mains switch shows you power | going in, the 12V lamp shows power going out - an easy visual to it | working).
You're wasting 12v power there. Put it on the 5v side, let it be a bit dim. If you need it to be brighter, use a 6 volt auto/motorcycle bulb.
You also don't need an external switch if you use a AT power supply. You probably have the switch that came with the computer, so just use it instead. (Shorten the cable if needed, but other than that, it's simple.)