Problem With Driving a BLDC motor

Thread Starter

arman74

Joined Jul 1, 2017
37
Hi.
I have a two phase BLDC motor that the elecronic driver is not working.Im trying to make a driver for it.I used its own driver to create my own circuit.I control the driver with a stm8s mcu that is a 5 volt mcu.The problem is that the high side mosfet just burn after a few second the motor starts and the motor wont work anymore.I dont know whats the problem with my driving method.I think its my program .Because the circuit is just as the same as the old one.

The motor is 6 ohms but I dont know the inductance.
The program is just as below:
1:H2,L1 off H1,L2 ON
waiting for interrupt created by Hal sensor.
2:H1,L2 off H2,L1 ON
waiting for interrupt created by Hal sensor.
.
.
.

For making H1,H2 on I just make transitor bases High,but for the L1,L2 I use pwm to control the motor current.I mean that no pwm is used for high side mosfets.

The mosfet I use is AO4614B.
upload_2019-5-8_5-12-56.pngupload_2019-5-8_5-12-56.png
 

Attachments

Thread Starter

arman74

Joined Jul 1, 2017
37
Can you confirm the motor technology?
BLDC and only Two motor connections??
That is not two phase.
Max.
Yes.Mostly they have 3 wires and 3 phase but the one I have has only 2 wires.Thats because it rotates only in one direction.There are only 4 coils in series.The magnet has two poles and there is just one halsensor.
 

MaxHeadRoom

Joined Jul 18, 2013
19,416
Yes.Mostly they have 3 wires and 3 phase but the one I have has only 2 wires.Thats because it rotates only in one direction.There are only 4 coils in series.The magnet has two poles and there is just one hallsensor.
So all coils are energized regardless!!??
Is this a motor with internal commutation as in a fan motor?
Max.
 

Thread Starter

arman74

Joined Jul 1, 2017
37
So all coils are energized regardless!!??
Is this a motor with internal commutation as in a fan motor?
Max.
Yes all the coils are energized at the same time and make the rotor rotate 90 degrees.
What do you mean internal commutation?If you mean that the driver is inside the motor case yeah it does.
 

Thread Starter

arman74

Joined Jul 1, 2017
37
One p channel mos and one n channel mos is inside each IC and i tried just turning on one low side with its opposite high side and I found that each one that the low side is on is overheated.
I think the pmos cant tolerate this overheat and just burns.Am i true?
If yes so what should I do?
 
Top