Adding an LED to a Mosfet mod

[The Curse of Millhaven]

Hey guys. This is probably fairly basic, but I am curious about adding an LED to an E-pipe. I'd like to put a dim red or orange light under a bit of frosted glass at the cap. I am using the design below, but without the 1k resistor and with a 20m pull down resistor instead of the 2-4m. I have two pipes up and running beautifully with the design. I know how to wire an LED in, but does using, say, a 1.5v led mean that my 3.7v battery is only going to deliver 2.2 volts to the battery?

Thanks in advance, big brains.

Here's the diagram (from the homebrew lightsaber thread).

 

[nicotime]

Voltage doesnt work like that...your atty and the LED will see the same voltage and is why you will need a resistor on one leg of the LED so it doesnt burn it out. The current the LED draws will be insignificant to the atty.

 

[The Curse of Millhaven]

Thank you!

 

[JohnnyDill]

Here is an example of how to trigger an LED with the current from an atty. Hope this helps.

 

[Visus]

He can wire it directly off the drain with a resistor. It will only turn on when the atomizer is on.

Johnny that design is for a dna it has power always feeding the board and and triggered by a logic power button.. If you could wire off the dna mosfet ya could use that drain too but its too tiny.

 

[The Curse of Millhaven]

That is the plan. I do have a DNA30 sitting in a box, though. Someday I'll see about cramming it into a pipe.