Hi Guys and Girls,
I have a problem with my DC Speed controller. To give bit of background, Ive been building high current DC controllers for 24v 750w e Bike motors (60A).
I haven't had a problem with any of them up until one customer with a Bosch 750w 24v motor. Every time he connected it to the speed control, it will work fine with a small load, but as soon as he would try and ride around on his bike it would fry the controller within seconds.
So after replacing the controller 3 times, he sent the motor to me.
I played with the motor on the controller and it ran fine, but when i stalled the motor and began to turn the controller speed up, it quickly kills the diode.
And once the suppression diode is dead it literally fries the controller.
The controller uses a 10A SR1060 Schottky barrier diode because I've had no problems with these before and they are quite high current for these types of applications.
Anyway, to try and solve the problem I then ran a 40epf06pbf (40a) diode on the motor to suppress the back emf from there, and again i tested, and the sr1060 blew (though slower this time) and the bigger diode got hot to the point where it began to smoke.
Somethings wrong here, the motor should not be putting this much current back to the suppression diodes.
If i run the motor without load the diodes don't get hot at all and it runs fine, it always happens as soon as there is a load on the motor (and only this particular motor)
Is it possible the motor has shorts between the internal coils? What else could it be causing this much back current?
Hope this is understandable, and hope maybe I can get some help or advice!
Just to add to this, if i run the motor at full speed and begin to stall it from there, theres no problem, its only from when the motor is under load as it is starting up.
Cheers!
Byt
I have a problem with my DC Speed controller. To give bit of background, Ive been building high current DC controllers for 24v 750w e Bike motors (60A).
I haven't had a problem with any of them up until one customer with a Bosch 750w 24v motor. Every time he connected it to the speed control, it will work fine with a small load, but as soon as he would try and ride around on his bike it would fry the controller within seconds.
So after replacing the controller 3 times, he sent the motor to me.
I played with the motor on the controller and it ran fine, but when i stalled the motor and began to turn the controller speed up, it quickly kills the diode.
And once the suppression diode is dead it literally fries the controller.
The controller uses a 10A SR1060 Schottky barrier diode because I've had no problems with these before and they are quite high current for these types of applications.
Anyway, to try and solve the problem I then ran a 40epf06pbf (40a) diode on the motor to suppress the back emf from there, and again i tested, and the sr1060 blew (though slower this time) and the bigger diode got hot to the point where it began to smoke.
Somethings wrong here, the motor should not be putting this much current back to the suppression diodes.
If i run the motor without load the diodes don't get hot at all and it runs fine, it always happens as soon as there is a load on the motor (and only this particular motor)
Is it possible the motor has shorts between the internal coils? What else could it be causing this much back current?
Hope this is understandable, and hope maybe I can get some help or advice!
Just to add to this, if i run the motor at full speed and begin to stall it from there, theres no problem, its only from when the motor is under load as it is starting up.
Cheers!
Byt