I have a question about E-cig. circuits. I just recently opened one. what im not understanding is why does it even have a controller? seems what the board wants to output is low voltage high current. that could be done with a direct connection from the battery to the coil. adjustment could be thru a simple potentiometer? least that's what I'm thinking the controller on the circuit board seems to be controlled by a pot. anywayz? so ya I'm wondering whats the deal with the board? thanks so much in advance.

 

The board will be controlling the current to a safe level, possibly temperature control and monitoring the battery voltage before it gets to a minimum working voltage.

 

that all makes since. i could see someone burning a coil if left with only a pot. to adjust the flow or damaging it by running it to low?? ummm not real sure on that aspect. well no i could see use in that as well. even manually adjusted you only want your battery to run but so low.... ok its all coming clear i think. awsome. thanks for the input!

 

that all makes since. i could see someone burning a coil if left with only a pot. to adjust the flow or damaging it by running it to low?? ummm not real sure on that aspect. well no i could see use in that as well. even manually adjusted you only want your battery to run but so low.... ok its all coming clear i think. awsome. thanks for the input!

Also, these devices use a oscillating on/off to control the temp (turning up power means more fraction at full power than off, turning down means increasing time in off state vs on state). This change of duty cycle is known as pulse width modulation.

If you try to control with a potentiometer, the potentiometer will get hot as it limits current flow to your device and heat/energy is wasted (battery life is wasted).

 

again a point i can relate to. its real nice to get some solid answers. thanks again!

 

Ok but what about all this for a disposable e-cig. 1 time use, no adjusting heat nor need to?? Then why so much put into something that's self sufficiently maintained until thrown away!?

 

Ok but what about all this for a disposable e-cig. 1 time use, no adjusting heat nor need to?? Then why so much put into something that's self sufficiently maintained until thrown away!?

Simple. Electronics are relatively cheap. Keeping material and assembly costs below certain threshold (say 30%) will generate sufficient profits at high volume.