Amp draw on DNA20?

[Quoiyaien]

I am a little unclear on how the dna 20 draws amperage form the battery... looking at ohms law, the higher resistance used to achieve the same wattage, the lower the amp draw... however I have heard conflicting views on how exactly this applies to the DNA20...

Lets say you have a 0.7 ohm coil at 20 watts... that has a ~5.3 amp draw
whereas a 2.5 ohm coil at 20 watts draws 2.8 amps

with the boost circuitry I am just wondering if this still applies? Im trying to figure how exactly the board draws current from the battery..

Can someone shed some light on this subject for me?

Cheers!

 

[Hoosier]

The battery just sees the power at its fixed voltage. So for both your examples the battery is outputting about 5.4 Amps. P=VI or I=P/V so I=20/3.7

What the dna is doing is converting some of those amperes to voltage.

The power out of the battery is the same as the power output of the device. (Plus some for circuit inefficiencies, but it's close enough to call it the same for this discussion.) The difference is the battery has a fixed output voltage while the dna-20 can vary voltage to maintain a constant power output.

 

[dr g]

http://www.e-cigarette-forum.com/forum/blogs/rader2146/3500-calculating-battery-drain-current.html

 

[Quoiyaien]

Thanks guys! That certainly clears that up