Ayne

I found this circuit on NET, and want to ask some things about this circuit.

Can i use MAX5056 4A, 20ns, Dual MOSFET Drivers,
http://datasheets.maxim-ic.com/en/ds...54-MAX5057.pdf

Which Schottk to use???

and need help how it controll motor speed?? I mean how PWM control the speed of DC motor any tutorial or web that can help me.

Thanks.

Attached Images

HBridgeSchematic.gif (10.9 KB, 37 views)

dknguyen

Since motors are inductive, the current in them cannot change instantly. What PWM does is jump the voltage between +V and GND at a certain duty cycle so fast that the current in the motor cannot change very much THe result is the current flowing through the motor under it's current speed and torque is the same as if you just applied a battery with a constant voltage of[Duty Cycle %] x [+V]. That's how speed is controlled by PWM.

OutToLunch

you can't use a mosfet driver to drive a motor. when they say it is a 4A driver, that means that it can supply that current to the gate of the FET. it is not a continuous rating - fets only need a high spike of current to charge the gate up - once it is charged, the current to keep it on is negligible.

you need to use mosfets to drive the motor. to drive the mosfets you are going to need a driver that will drive the low side fet and the high side fet.

Ayne

I got the motors from a toy car and it taking 250mA at full load at supply 11 volts, i tested with Multimeter.
a capacitor of 100nF is attached with motor terminals, now i want to use this motor with the above circuit which i have posted before.
Which is the right way to connecting this motor to above circuit... remove this capacitor from motor or not???

May be some one say ur motor current is low, then why u r using high current MOSFET drivers the answer is, i am planing to use better motors with this circuit later.
Thanks

Ayne

I make this circuit, but i never make any H Bridge before, i mean this is first time i am making a circuit to control DC motor.

I need ur guidence.
Plz check this circuit, It will work OR Not???

Well known "mosfet complementary pair" for 50 Volt 3 Ampere ???

Need some improvements or not in the circuit??

Attached Images

H Bridge.GIF (15.1 KB, 29 views)

cadstarsucks

In theory, yes. In practice you need to split the timing of the top and bottom FET so component tolerances do not turn them on at the same time.

D.