hello, i was just wondering what are you guys using to protect servo from burning of stall currents?
i need to limit servo current to 1amp max so i doesnt burn, what do you guys think is best option
Why are you putting the servo in a situation where it stalls?
Maybe you just need a bigger servo?
As the current in the motor is controlled by the electronics inside the servo I don't know how you could have a useful external protection circuit.
...R
Its a robotic arm servo which is controlled by pwm and it sometiems get to angle where ot cant go further ( if its not set to atarting point ) and it wants but cant... So stalls
You need to measure the current the servo is pulling and implement a cutoff - or find a more sophisticated
servo that does that itself. A shunt or hall-effect current sensor module perhaps?
cr0wl:
Its a robotic arm servo which is controlled by pwm and it sometiems get to angle where ot cant go further ( if its not set to atarting point ) and it wants but cant... So stalls
The answer to that is a more sophisticated control program. Why would you write a program that can command a servo to move to an impossible angle?
...R
A servo draws the stall current every time it starts up.
I agree with Robin2. Write the program so that the servo is not driven past its limits.
It is simple to determine those limits and write the code accordingly.
So do you guys have any idea to do that?
cr0wl:
So do you guys have any idea to do that?
Not without seeing the program that is failing to do it.
...R
So do you guys have any idea to do that?
Yes. I'm surprised that you would not.
One of many possibilities:
if (servo_command > lower_limit && servo_command < upper_limit) servo.write(servo_command);
cr0wl:
So do you guys have any idea to do that?
I like to use the knob tutorial to do this. Use a potentiometer (knob) as the input. Map that to servo command and send it to the servo. Also print it to the serial monitor.
Carefully turn the knob back and forth until you hear the motor bind. Then back off. Don't leave it with the servo bound up or it can overhead and melt.
Note what values make it bind and put limits in your code to keep it within those boundaries.
Measure the temperature of the servo(s). If they get hot, turn them off.
Of course this means your device stops working but applying a current limit to a servo also stops it from working. It is like driving a car with a block of wood underneath the brake pedal to limit the brakes.