ESC Connenction

[SSR]

Hi all.

This is a type of silly question, but any ways i want to clear my self.

In an ESC there are 3 wires on the o/p side for motor connection. On the i/p side there are 2 wires that goes to the battery and 1 wire that is the BEC.

If that is all than what makes the connection b/w the controller and ESC for throttle control?

 

[thepelell]

the 1 wire you say is the bec, is actually 3 small wires, a red, a black and a white one. Red and black are +5v and ground. White wire is the signal that controls throttle.

 

[SSR]

So if we want to run the motor on 50% throttle, then we would apply a sq. wave of 50% duty cycle?

 

[691175002]

So if we want to run the motor on 50% throttle, then we would apply a sq. wave of 50% duty cycle?

50% throttle would be 50hz square wave with a 7.5% duty cycle. The control signals are not PWM. Look up servo/PPM control instead.

The maximum update rate for an ESC/Servo varies greatly from 50-400hz based on firmware etc.

 

[SSR]

But as per my knowledge servo works on PWM not PPM.

And from 50% throttle i want to mean if the frequency is 1Hz then the on time of the pulse would be 0.5sec.

This is what i have picturized in my mind.

 

[691175002]

RC Servos function based on pulse width not duty cycle, it is not PWM:
http://www.luolamies.org/misc/servo.html
Analog servos only power the motor once per pulse which means that driving them too slow causes the motion to be very jerky and driving too fast can burn out the electronics/motor.

Digital servos can use basically any frequency but some of them are capped at 333hz because they expect at least 1ms between pulses.
Naturally, you cannot drive anything faster than about 490Hz because your pulses must be at least 2ms long. Only certain products work at that speed though.

 

[SSR]

Hi. I have bought a hobbyking 20 amp ESC (http://www.hobbyking.com/hobbyking/...0A_Fixed_Wing_Brushless_Speed_Controller.html). The red of battery is conncted to red of ESC and black to black.The throttle signal comes from the controller to white wire of ESC a 50 hz sq. wave with a 10% duty cycle(18 ms low,2ms high). The three output wires of ESC drives the motor. But the motor does not show any movement. What's wrong i am doing?