5 ms·

This is very cool! I'm worried about the long term stickiness of the LEDs/Timers/ICs. If I was to buy this I'd probably stick foil to the adhesive bottom of th

by columbo 13y ago

This is very cool! I'm worried about the long term stickiness of the LEDs/Timers/ICs. If I was to buy this I'd probably stick foil to the adhesive bottom of the components so they can be rested on top of the copper tape. That or put a few pins on the +/- areas. That way you can tape the copper to cardboard instead of paper and then punch the components through the tape.

csmuk 13y ago
I'd worry more about the power carrying capacity of the proposed conductors especially during partial failures. Someone is going to set fire to their clothes one day and it isn't going to be pretty.
- JoeAltmaier 13y ago
  Its low voltage. Seems unlikely.
  - csmuk 13y ago
    Stick some steel wool across a 9v battery and you'll get what I mean. It's the current, not the voltage. Video for you: http://www.youtube.com/watch?v=MWuJokR_mI8 http://www.youtube.com/watch?v=MWuJokR_mI8
    - bigiain 13y ago
      Yeah but - these are powered by CR2032s - typical capacity is around 200 milli Amp Hours, and they're usually rated at a maximum continuous current of 1mA with 10mA "pulse" capacity. That's a continuous 0.003W or pulses of 0.03W. It's probably not _impossible_ to start a fire with a pair of CR2032s, but you're going to have to set it up that way on purpose – the chance of "accidentally" creating enough heat to set non-intensionally-incendiary materials alight is low enough to be ignored. (Note, I carry a pair of these cells around in my pocket - an LED light attached to my keyring. These cheapo lights rely on the internal resistance in the battery to current limit the LED, with a white LED across a pair of cells, the battery's own resistance is enough to keep the current down under the "let the smoke out" limit of the LED - it might be more than 20mA, but it can't be heaps more.)
      - csmuk 13y ago
        They are powered by that here. The inevitable chain will be either the battery will go flat in minutes or there will be brown outs which are inevitable if you have LEDs and non MSP430 grade CPUs hanging off it. The result of this will be inevitably, judging by usual projects I've seen, either stick a PP3 in with a regulator or even worse chuck a cheap LiPoly on it. Then you're in trouble/on fire.

by columbo 13y ago

csmuk 13y ago

I'd worry more about the power carrying capacity of the proposed conductors especially during partial failures. Someone is going to set fire to their clothes one day and it isn't going to be pretty.

JoeAltmaier 13y ago
Its low voltage. Seems unlikely.
- csmuk 13y ago
  Stick some steel wool across a 9v battery and you'll get what I mean. It's the current, not the voltage. Video for you: http://www.youtube.com/watch?v=MWuJokR_mI8 http://www.youtube.com/watch?v=MWuJokR_mI8
  - bigiain 13y ago
    Yeah but - these are powered by CR2032s - typical capacity is around 200 milli Amp Hours, and they're usually rated at a maximum continuous current of 1mA with 10mA "pulse" capacity. That's a continuous 0.003W or pulses of 0.03W. It's probably not _impossible_ to start a fire with a pair of CR2032s, but you're going to have to set it up that way on purpose – the chance of "accidentally" creating enough heat to set non-intensionally-incendiary materials alight is low enough to be ignored. (Note, I carry a pair of these cells around in my pocket - an LED light attached to my keyring. These cheapo lights rely on the internal resistance in the battery to current limit the LED, with a white LED across a pair of cells, the battery's own resistance is enough to keep the current down under the "let the smoke out" limit of the LED - it might be more than 20mA, but it can't be heaps more.)
    - csmuk 13y ago
      They are powered by that here. The inevitable chain will be either the battery will go flat in minutes or there will be brown outs which are inevitable if you have LEDs and non MSP430 grade CPUs hanging off it. The result of this will be inevitably, judging by usual projects I've seen, either stick a PP3 in with a regulator or even worse chuck a cheap LiPoly on it. Then you're in trouble/on fire.