This project is currently being updated. Feel free to get your comments and suggestions in so that the feedback can be used in my next build.
There is a problem with the circuit. Please see the comment from Zanderist below. I have updated the schematic in the next step.
So when I wanted to quit smoking I tried an electronic cigarette. They were expensive and didn't produce enough vapor for me. I figured hey it can't be that hard and decided to look into making my own.
Approximate cost not counting batteries is about $12
I took my existing electronic cigarette and hooked it up to a voltmeter and started making notes. I found other electronic cigarette models that had variable voltages so I decided to search through several forums out there to see what range of voltages were being used.
I found that most operate off 5-8vdc with wattage being a little higher than just from the battery alone so battery voltage needs to be higher than what is being used and the amp hours need to be high.
I found that most electronic cigarette mods were using IMR 14500 3.5v Lithium Ion Batteries
Needing to control the voltage I looked at several voltage regulators and came up with the LM317 because it supports the volt range I'm working with. I also wanted to leave room for creating a desktop model.
Nicotine use in the US requires you to be 18 years of age or older but then again this project isn't about nicotine and I didn't use any when I really began to quit smoking.
Feel free to ask questions and/or make suggestions.
Use the first schematic in this step. This update is from working with Zanderist. This was originally designed for the LM317 voltage regulator but after suggestions from Zanderist the design is now using LM338t. Other schematics are from my first design and manufacturer specs.
As far as the math goes I've done it for you so don't worry too much. I calculated the values based upon 7.5vdc but the intended use is around 6.5 to 7vdc. I left in the overhead because as the batteries get drained you can crank it up.