0
\$\begingroup\$

What are the controlling input specifications of a Hobbywing Quicrun WP-1040 Electronic Speed Controller (ESC) for brushed motors? I assume it should use the standard PWM with 1 kHz frequency as stated in its manual? Do I have to find the "pulse length to motor speed/direction translation" by myself or are there any common conventions?

I want to use the ESC directly without a radio receiver to drive a Himoto RC540 26T motor in an RC car (Himoto Short Course Corr Truck 4WD RTR 1:10).

\$\endgroup\$
1
\$\begingroup\$

Generally all RC gear uses the same old pulse-width modulation scheme: a pulse whose length varies between 1 and 2 ms, repeating every 20 ms.

RC PWM

A pulse of 1 ms means "motor off"(airplane ESCs), "full reverse"(car ESCs) or "servo to the extreme left/right", while a pulse of 2 ms means "motor to full power" or "servo to the other extreme end".

The 1 kHz specification in the manual is about the motor output. The ESC switches the H bridge MOSFETS at 1 kHz at varying duty cycles in order to precisely control the motor speed.

A period of 20 ms means a frequency of 50 Hz, not 1 kHz like you assumed. Some components like RC helicopter tail rotor servos and multicopter ESCs are designed to also accept non-standard, higher frequency signals (500 Hz or less) for tighter control loops.

\$\endgroup\$
  • \$\begingroup\$ Thanks for your quick and clear answer! I badly misread the PWM principles. So I guess the motor should be stopped with 1.5 ms pulse as that seems to be a common "neutral" position. \$\endgroup\$ – Kozuch Feb 22 '16 at 11:35

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.