bring pin at ground?!

Projects Programming
1

Good evening (I hope not to have been wrong in the creation of the topic but it is the first message on a forum of my life .... in which case I apologize)

I'm using an elementary schetch on the false line of the example "blink", to control 6 power MOSFETs in parallel to feed a stepper having three cables

however mosfets that I am using (3,5 € each) do not close the gate if not feel exactly 0V ... (in practice give a variable resistance according to the gate potential), and for the structuring of the circuit (only possible) the engine does not reach a significant current if the gate that should be closed are not.

therefore at the time when I put the pin LOW command .... the gate of the mosfet junction N closes that half, and that does not open for half the gate of the mosfet junction P ......

apart enormously complicate the circuit by inserting 12 transistors that work well between HGH and LOW to control the gate of my mosfet .....

there is a solution in the Arduino programming to bring to the ground pin or at least really close?

many thanks in advance!!! I hope for a positive response

2

I am sorry but your English is difficult for me to decipher.

It would help to have a schematic or wiring diagram and the part number of your MOSFETs.

3

Your question is very hard to read - is that from Google translate? It is not a good translation.

MOSFETs don't need exactly 0 volts on gate to turn off. It just needs to be less than the threshold voltage (Vgs(th) on the datasheet). When off, there is a small amount of leakage, though - this is also specified in the datasheet.

That's the only part of your post I could understand.

Maybe related - MOSFET gate connected to nothing will float, like an input pin on the arduino. So the MOSFET can turn on in response to electric fields if whatever is connected to the gate isn't running. It is common to put a resistor 10k to 100k between gate and source, to keep the MOSFET off when nothing is driving the gate.

4

faller:
Is there is a solution in the Arduino programming to bring to the ground pin or at least really close?

It sounds to me as if you are going to have to put some electronics between the Arduino pin and the mosfet gate.

In the worst case a tiny relay maybe? Not sure if Arduino can directly drive mechanical relays...

http://forum.arduino.cc/index.php?topic=22083.0

The above says: "Maybe a Solid State Relay? The SSR needs 3 -32 vdc and not much current 3.4ma at 5vdc so the Arduino will do fine."

5

Really, you should post in the universal language... schematics! :slight_smile:

6

Hi,
Welcome to the forum.

Please read the first post in any forum entitled how to use this forum.
http://forum.arduino.cc/index.php/topic,148850.0.html
then look down to item #7 about how to post your code.
It will be formatted in a scrolling window that makes it easier to read.

Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?

Thanks.... Tom... :slight_smile:
OP has also posted this in Spanish Section of forum.