PWM value for ESC for APM 2.8 Board?

ArduPlane
1

Hi i have a question, i’m currently using this ESC (https://hobbyking.com/en_us/hobbyking-80a-2-6s-esc-4a-sbec.html) and in the spec sheet it says 8000 to 16000 PWN.
I noticed that in servo parameter list the PWN limit is 800 to 2200. So the question is do i need to something with the pwn value in order to increase the ESC draw ?, Or is it ok as it is ?

Also since its a 2.8 apm board currently i can’t access the ESC calibration mode and Servo output in the mandatory hardware. Also i’am aware of the 2.x board limitation and it only being compatible with older arduplane build but is there any way to go around this problem ?

In the end i need to draw 35 amps minimum for the current build. And i worry that if my calculation are correct then it will only output 22amp draw.

2200pwn/8000pwn= 0.275

0.275*80amp=22

2

I just make a list:

  1. PWM = Pulse Width Modulation, RC
    PWM uses a signal from about 1000us to 2000us. This is what the ESC expects.

  2. 8kHz to 16kHz is the mosfet switching frequency.

  3. The ESC is probably fine without calibration. It is a plane with a single ESC, not a copter where multiple ESCs need to be close together regarding input signal and motor rpm.

  4. Old unsupported hardware uses old unsupported firmware. The only way around it, is to buy a modern flightcontroller.

3

Hi thanks for the reply. I am currently limited with time as uni is about to start soon to buy and wait another board.

When you say the ESC is fine as is it would my current set up be able to get the max power rated ?

Also what is mosfet ?

4

Yes, I never calibrated an ESC on any of my planes (with or without autopilot). If the ESC does not arm itself, lower the minimum PWM output value. If the amp draw does not increase anymore before the throttle stick reaches its maximum, you can lower the maximum PWM value.
If the amp draw was still rising when the throttle stick reaches max, increase the maximum PWM value.

A mosfet is a type of transistor used in ESCs. The ESC switches it on and off to control the voltage going to the brushless motor. The switching frequency needs to match the type of motor you are using. Brushless outrunners will most likely run on any setting. Higher kV inrunners will need higher switching frequnecies.
The switching frequency also influences the noise the motor coils make below full throttle and the efficiency. Higher > less noise, less efficient.

5

I always calibrate my ESC when using PWM. That way in manual mode you can use the full range of the throttle stick.