Science Buddies: "Ask an Expert"

Dear Sir/Mam
I tried the experiment of making an electric field detector however it did not detect anything
I have a few doubts
Why is it that we have to specifically use mpf102 transistor ?
Can't we use any MOSFET transistor?
Thank you

Hi Vivid16,
I am sorry to hear that you experiment isn't performing.
In regards to the reason for that particular model of transistor, the short answer is that it is because of the circuit voltage (9V). You can probably use other JFETs once you adapt the circuit to it. Here's a link that would hopefully give you some more insights in this regards:

http://www.hawestv.com/amp_projects/fet ... 2-sub1.htm

Good Luck and please let us know if there's anything else we can do to help!
Willey

I have tried this project but the LED kept burning out because the nine V battery . One of my suggestions would be to use a snap circuit with 2 AA batteries so the power would not be too high and not too low also it is much safer.Sorry for the disruptions .
Sincerely,
Louis.