Complimentary Pair Mosfet or Best Practice.

Thread Starter

paultyrer

Joined Jul 29, 2009
6
Source voltage 12v (car battery - Vehicle is negative ground.)
Control with Arduino mega - Logic 5v
Driving Hydraulic solenoids x 16 Amperage of each individual 1.4amps


I have designed 3 or 4 circuits so far using Mosfets.

N channel mosfets work well, but switching low side and in practice could be a problem for -ve ground
P channel works well but logic levels are problematic.
I have completed the circuit also with 2n2222 instead of the N channel, and driven the P channel with this and this works great too.

I am currently driving a P channel mosfet with a N channel and this works great, Does anyone know of a replacement for this circuit, instead of 2 separate mosfets would a complimentary pair work in this setup and if so recommendation of a part number ?

Or am I over thinking the entire thing. Sometimes its great to take a back step, hence why I am reaching out.
 

BobTPH

Joined Jun 5, 2013
2,538
You are overthinking the problem. The KISS principle calls for a single N-channel MOSFET.

Why do you say switching the low side is a problem? What problem are you experiencing?

Bob
 

Thread Starter

paultyrer

Joined Jul 29, 2009
6
Currently the solenoids on the vehicle have a shared ground, if I remove the shared ground and supply a 12v and ground to each solenoid this would work well. I worry however should anything touch the ground or chassis of the vehicle I now have a dead short.

If I provided a shared 12v and switched the ground this would work also but would be a problem for the rest of the vehicle.

Everything works on the bench perfectly and KISS with the N was my first choice, This is an existing running and driving vehicle I am adding hydraulics to, the solenoids are simple, ground and 12v. - I ideally need to switch the 12v high side and not the ground.
Hopefully this makes sense.
Thanks again
 

Papabravo

Joined Feb 24, 2006
14,398
Currently the solenoids on the vehicle have a shared ground, if I remove the shared ground and supply a 12v and ground to each solenoid this would work well. I worry however should anything touch the ground or chassis of the vehicle I now have a dead short.

If I provided a shared 12v and switched the ground this would work also but would be a problem for the rest of the vehicle.

Everything works on the bench perfectly and KISS with the N was my first choice, This is an existing running and driving vehicle I am adding hydraulics to, the solenoids are simple, ground and 12v. - I ideally need to switch the 12v high side and not the ground.
Hopefully this makes sense.
Thanks again
What exactly is the difference between the "shared ground" and the +12V ground which should be the same as battery minus and the the vehicle metal? Can you verify that they are isolated?
 

Thread Starter

paultyrer

Joined Jul 29, 2009
6

Thread Starter

paultyrer

Joined Jul 29, 2009
6
What exactly is the difference between the "shared ground" and the +12V ground which should be the same as battery minus and the the vehicle metal? Can you verify that they are isolated?
My apologies, by shared ground I meant -ve lead off the battery.
 

Papabravo

Joined Feb 24, 2006
14,398
I think the KISS just went out the window. This being a 8v chip, The 20v Version has too low an amp limit.
What is the penalty for continuing the search a bit? Are you in a great big hurry to come up with a solution?

Get yourself a Dual-N and a Dual-P from NTJD family and you have a simple solution
 
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