SparkFun Electronics will be closed in observance of memorial day on Monday, May 29th. We will resume normal business hours on Tuesday, May 30th. Any orders placed after 2pm Mountain Time on Friday, May 26th will process and ship out on Tuesday, May 30th.


Member Since: June 26, 2009

Country: United States



Biodigital Glue



  • If you measure the resistance of your test leads, I think you’ll find them equal or greater than the vape coil. If that’s the case, 2/3 or more (!) of your power is being used to heat the leads and not the coil. In other words, your coil can be 3-4 times more powerful just by using different wires to hook it up! It’s easy to think of Ohm’s Law as applying only to particular parts in a design, but a circuit is always a continuous loop. Every part of the loop has some V=IR description that you can model, and they all add up to match the whole.

  • You might want to run some power loss calculations on the (undersized) test leads you used to connect the coil to power. ;-)

  • Maybe they gave you 4 figuring you might end up with 2 working ones.

  • Yay, gov regulations that make some attempt to balance the desires of commerce vs. my desire to not Die In A Fire (on a plane!)

  • From the look of them, you can’t cut them to shape. I’d build a sort of heat-pipe. Think: metal paperweight, with the base the size of the heating pad, and the top having the profile you want.

No public wish lists :(