I'm trying to make h bridge and have some question.
The picture of two is circuit that just R3 resistor's location is different.
And NMOSFET is irfz44n. not a 2n6755. and I useing arduino pwm signal
Left circuit is just make 5v signal to 12v.
And make reverse amplification
My question is when I operate those two, I get a different result.
The picture that is close to V2,when I flow full current to mosfet gate, V2 is 11.5V.
However, the other circuit that R3 is under the mosfet is 8.5V.
It is difficult to think the effect of transistor. Maybe.
irfz44n is not spec'ed for logic level voltage on the gate - you need to put 10v on the gate to turn it on fully. When driving MOSFETs with the Arduino, you need to use a logic level gate MOSFET or a gate driver that supplies the required gate voltage.
I can't tell from those diagrams how you're driving it? Where is the Arduino?
Replace the 1st MOSFET with a switching BJT such as a 2N2222, give it a 1k base resistor, then the
second MOSFET will get full 12V drive.
A non-logic level MOSFET like these needs 10V minimum drive to give the performance quoted in the
datasheet.
If you want to drive a power MOSFET at high frequencies of PWM, a gate driver chip is needed as
the gate is very current-thirsty then, being highly capacitive.
And yes 122.jpg is not workable, you never use source-follower for switching a power MOSFET,
but both circuits are broken anyway as two pieces of the circuit have only one wire between
them - so each is an antenna for the other. You didn't common the grounds, but we all assumed it!
