Monday, August 27, 2012

Tour of Duty

I'm thinking about the lights outputs -

They will take quite a lot of amperage if they're all lit at the same time, so I'm thinking about having a 25% duty cycle or similar. That way only 24 lights can be active at the same time, consuming around 6A - unless my calculations are way off.

I should mention, this is using bulbs. Using LED's it will consume far less power.
The biggest problem is that I only got 8A fuses but hopefully there's larger fuses available.
Either that or I'll need to put the +5 VDC through multiple fuses, which requires a little work.


  1. I was testing my GI circuit this weekend, 32leds are REALLY bright, but powered to a 3.3v rail only used 0.3amp.. so if I max 64leds for my GI, it should be about 0.6-0.7 amp max... Last night I sent a design into batchpcb to get some test pcb fabbed (just because!), so I made a circuit you can daisy chain together, each board giving 16 led from 1 led controller chip, its very nice, those 16bit serial shift chips with constant current output are fantastic.

  2. I should say 32leds ran at 0.03amp on my bench psu, so I expect 0.06-0.07 amp, not 0.6 :). Running it off a 5v rail I think it soaked up 0.4amp for 32leds (I dont remember now, but 3.3v is sufficient)

  3. Nice! :D

    The board I've made is also daisy-chainable, but would need three wires to be soldered. I don't think I'll be needing more than 64 switches and 96 unique lights (or light chains) anyway... :)

    I have a lot of LED's as well, so I could probably do an all LED table, but I've compared bulbs and LED's - and the bulbs wins all the time. Besides in power consumption.

    I kinda wish I'd made custom PCB's however... :)

  4. Using standard comparisons charts at, it would seem all 96 lights would draw around 14.4 A if they're all on at the same time. A bit too much. :D