Hi, I'm trying to make a switch with a MOSFET.

I connected battery(11v) on drain side with motor connected,

gate is connected to ARTIK which is a control voltage 0v to 5v

and source is connected to ground.

I used 2n7000 MOSFET.

when I don't connect anything on the gate, motor doesn't work but

whenever I connect something(0v or 5v or ground) motor works. it supposed to only work when the gate voltage is 5v..

I have no idea what is going on.

I also connected 10K resistor gate to source to make pull down.

Please help..

 

Welcome to AAC!

Post a clearly focused closeup picture of how you have things connected with ground connected to the gate. Label drain, source, and gate.

 

Thank you for the reply!
I connected one of the ground pin in the ARTIK board.
I also tested it with a voltage supplier but it acted same.
I cannot take a picture since it is in lab right now.
I will take a picture and post it here tomorrow!

 

Be sure all component voltages are referenced to the same common ground, and that you have the pinout correct for the MOSFET. These are very simple things but also very easy to get wrong. Check and double check.

 

Here is my connection picture.
One more thing that I notice that when I connect ground on the gate,
Motor turns faster than when I connect voltage on the gate..

 

I just tested with a voltage supplier as a gate voltage (set it as 5v)

whenever I connect to the gate, the voltage supplier reads 11v (which is battery voltage) and motor doesn't turn on

when I connect ground from voltage supplier to the gate, it doesn't work.

but ARTIK board ground as a gate turns motor on.

 

Here is my connection picture.

Do you have a common ground for all circuits?

Do you have a snubber diode on the motor? Have you tested the MOSFET to see if it has been damaged back EMF or static?

I know to be mindful of ESD, but I've still damaged several 2N7000 in the past year. The only cause I can think of is improper handling. IIRC, a couple of them sort of worked, but were leaky.

 

Make sure the battery is connected the right way round.
Make sure it a 2N7000.