PWM does not rotate motor

[leonepedro]

Hello, I am an electronics technician and made a circuit to drive a 5A 12V motor. I need it to rotate only for one sense, but I need to control the speed. I'm using PWM for this.
I've done a circuit for that. When the engine is without load, works normaly at high, medium and low speed rotation, but when I place load, the engine at high speed rotates normal, but at medium speed and low the engine stop after 1 second turning.

I am using the IRF3205 Mosfet with a 4427 drive CI.

What may be happening? The engine with load for the medium and low speed.

I am sharing the circuit for you to help me identify the error.

I'm using 150 (high), 65 (medium) and 45 (low) pwm. Is it little for the motor?

[kmin]

@leonepedro

When the engine is without load, works normaly at high, medium and low speed rotation

My motors don't even start with circuit like that...

[jremington]

Better to use a logic level MOSFET in a circuit like this:

[leonepedro]

I'm new to Mosfet, does this Logic Level Mosfet work with PWM?

Which model do you indicate to drive a 5A 12V motor?

[jremington]

Yes, most MOSFETs can be used as switches.

Select a logic level MOSFET with rated drain current at least 2X the motor start/stall current.

For a "5A" motor, the start/stall current can be 25A or more, so check or post a link to the motor data sheet.