MorganS:
What is the duty cycle? Can you use a car battery and a 10A charger to keep it topped up?
Noy sure about the duty cycle. Also I don't think that a car battery will supply enough current to keep an anywhere between 70A to 100A of constant current for 30 min to an hour long show. And if I have to keep it topped up via a wall plug then isn't the battery redundant?
Google:
An average car battery has a capacity of around 48 amp hours which means that, fully charged, it delivers 1 amp for 48 hours, 2 amps for 24 hours, 8 amps for 6 hours and so on.
so that's almost 50 amps for for 1 hour, which is close but a power adapter for 50 amps is about 45 bucks on Ali or Ebay. Soooo it is pretty redundant. And it's not that there isn't an accessible wall plug on site, these are bars and clubs that are outfitted with a stage and AC wiring outfitted to drive Almplifies, Cabinets, PA system and lights at once.
And yeah, I'd assume that a transformer of that size would be pretty pricey in of itself which is why I'm looking at just buying a core and winding one myself.
Now let's say I can segmend the power supplies. Instead of one 100A+ power supply I can divide the lights into equal halves and power them from 2 separate 50A supplies. Or even divide it into quarters and use 4x 25A (or 30A to leave some overhead) power supplies. The total cost would still be about the same (1x 30A 12v power supply goes for $28.65 CAD sooo that's pretty much $120 for 4 of those... )