building your own esc
06-05-2003, 03:14 PM
#2
Senior Member
Join Date: Jun 2002
Location: MD
Posts: 256
Likes: 0
Received 0 Likes
on
0 Posts
building your own esc
Here is a good site: http://www.math.niu.edu/~behr/RC/speed-ctl.html
Brushed ESCs are pretty simple. There are one or more MOSFETs to switch the motor on and off. At full throttle they just stay on; at zero throttle they stay off. Anywhere in between and they switch on and off rapidly, usually somewhere in the 1 - 10 KHz range. If you're at 50% throttle they will be on half the time and off half the time, at 75% throttle they will be on 75% of the time and off 25% of the time, and so on.
If you know how to program microcontrollers you can use one of those to read the signal from the receiver and generate the pulse-width modulated (PWM) output to the MOSFET(s). A signal at a few KHz isn't that hard for something running at several MHz. You can also put in cool things like arming so the motor doesn't get started accidently.
If you don't have the tools and experience to do it that way there are also some circuits using timers and logic gates and things. I'm not quite sure how those work but the idea is the same; you turn the servo control signal from the receiver into PWM.
Brushed ESCs are pretty simple. There are one or more MOSFETs to switch the motor on and off. At full throttle they just stay on; at zero throttle they stay off. Anywhere in between and they switch on and off rapidly, usually somewhere in the 1 - 10 KHz range. If you're at 50% throttle they will be on half the time and off half the time, at 75% throttle they will be on 75% of the time and off 25% of the time, and so on.
If you know how to program microcontrollers you can use one of those to read the signal from the receiver and generate the pulse-width modulated (PWM) output to the MOSFET(s). A signal at a few KHz isn't that hard for something running at several MHz. You can also put in cool things like arming so the motor doesn't get started accidently.
If you don't have the tools and experience to do it that way there are also some circuits using timers and logic gates and things. I'm not quite sure how those work but the idea is the same; you turn the servo control signal from the receiver into PWM.
