Mosfet question

[Oldgrandpainmi]

Hello all!
Newbie here, to both this site and to mod box's. Please excuse me if this post is done incorrectly.

I have been studying online schematics to mod box's for a while. I have a question regarding the mosfet in the circuit below. (It is a common schematic all over Google, not the one I'm developing.) In the circuit, what is the minimum gate voltage required to trigger the MOSFET?

Thanks all!!

 

[Rabbit Slayer]

MOSFET turns ON when gate-to-source
is more than about 2v (2v to 5v)

 

[suprtrkr]

According to the Data Sheet for that MOSFET, the Gate-Source Threshold voltage is a minimum of 1V and a maximum of 2.5V

 

[Mooch]

Hello all!
Newbie here, to both this site and to mod box's. Please excuse me if this post is done incorrectly.

I have been studying online schematics to mod box's for a while. I have a question regarding the mosfet in the circuit below. (It is a common schematic all over Google, not the one I'm developing.) In the circuit, what is the minimum gate voltage required to trigger the MOSFET?

Thanks all!!

Welcome to ECF!

That MOSFET will start to turn on at, worst case, 2.50V. But that is only for 0.00025 amps. To turn it on hard enough for vaping you'll need more voltage than that, 2.7V at least. Preferably 3.0V if you are drawing a lot of current.

These are all worst case scenarios though. You might be able to turn it on as low as 2.0V but this voltage changes slightly with each MOSFET. In my opinion, it's best to plan for the worst.

 

[Oldgrandpainmi]

Thanks for all of the reply's. I appreciate it. As I get further into this new hobby, I'll probably have more questions!

 

[Bunnykiller]

look into IGBTs ....

 

[Mooch]

look into IGBTs ....

I've always wondered if anyone had done this before! Do you have any links to igbt mods? A google search turned up empty.

 

[Bunnykiller]

no links to mods but they behave the same but with better turn on characteristics, better current ratings....

 

[Mooch]

no links to mods but they behave the same but with better turn on characteristics, better current ratings....

Thanks!
I've only done a bit of playing around with them as I have always stayed with MOSFETs for my designs. I associate IGBT's with much higher power levels (their higher current ratings as you mentioned) as I thought their characteristics at lower current levels (forward voltage drop, etc.) typically weren't as good as what can be achieved with MOSFETs at the lower power levels we vape at. But you've peaked my curiosity! Thanks again!

 

[mauricem00]

with an igbt the minimum voltage drop across the device will be equal to the base emitter voltage of a high power transistor plus the drain source drop across the mosfet used to drive the transistor. or about 0.8 volt at high current.mosfets on the other hand are variable resistance devices and voltage drops as low as 0.06 volts at 20 amps. the igbt is a darlington configuration that uses a low power mosfet to drive a high power bi-polar transistor and has been replaced in most high power switch mode structures with more modern high power mosfets.igbt are 30 year old technology.