I am looking for a bit of advice on how to use a mosfet in conjunction with a female dc charge port and dummy jack as a means to turning a motor on and off as dummy jack is inserted or removed? Any ideas if it's possible and which mosfet I require? The project is using 3.7v 120mah lipo rechargeable battery running a 2v dc hobby motor. Any help much appreciated.
So which is it? Do you want to turn the motor on or do you want to turn the motor off?
If you want the motor off when the jack is inserted, make sure you get the kind of socket which has 3 connections. One will be opened (disconnected) by the jack when it is inserted. If you want it on when inserted, just make the dummy jack have a connection between the two pins.
There has to be more to it than you've said so far or no MOSFET is needed.
Use real jack, not dummy. Wire motor to socket and wire battery to jack. Plug battery into socket, motor runs. Unplug battery, motor stops. Job done.
Or connect socket inline in positive lead to motor. Dummy jack is shorted. Plug jack in motor runs, unplug jack motor stops. Still no MOSFET needed.
Steve
No, that's not job done, that's arcing and possibly burnt out jack... Motors are inductive loads and
you need a free-wheel diode. The jack's current rating may be less than the motor's current too.
Also jacks short themselves out during the insertion so connecting a battery via a jack is a no-no.
I was rather hoping the OP would give us some real details so he could get a more reasoned answer...but no such luck.
And I was assuming that "female dc charge port" meant a barrel-type DC power connector. They don't short out when connected and some of them are good for well over 5A, plenty for anything that is running from a 120mAh single cell. I guess you are thinking of something like a 3.5mm audio jack and I'd agree they're not good for most motor connections though I've had plenty of guitar pedals that used them for low current DC connectors without problems.
Steve