motor power supply

[pizza]

hi all, im new to rc helicopters, still learning how to fly and basic concepts. eventually, i wanna build my own quadrotor, but im not good with electronics. been doing research, but cant find some answers to fundamental concepts.

the lipo supplies voltage to all the ESC, receiver and motor with the help of BEC inside the ESC, supplying a clean 5V, 1 to 2A to the receiver and system depending on the BEC voltage regulator.

however, the voltage pumped to motor is unregulated. which means a drop in battery voltage of the battery will directly affect the output to the motor.

however, i was told my a senior that it is impractical to find a voltage regulator for the motors, because one such outrunner sources up to 12A, and so far the voltage regulators in the market supplies only low current.
even if such a regulator exist, the heat generated will burn the voltage regulator, even with a heatsink. and low efficiency.

so the question is, how will battery voltage drop affect motor performance? how do you implement it in your system?

[Super-Hornet]

What u are looking for is to have a constant RPM to the motor right?
If yes, then u should look for ESC that can do "governor mode".

Most ESC that design for helicopter can do governor mode BUT not all ESC...thus u have to check. And....different brand of ESC has different quality of governor mode. Some perform better (better at controlling the RPM) and others.

What do the governor mode do is that, it send constant PWM to the motor and thus motor spin at a predefined RPM (depend on the RPM u set). When the battery voltage drop or when there is load act on the motor to slow it down, the ESC will automatically send at higher PWM (or more "ON" state in the PWM pulse) to the motor and thus making the motor to spin at constant RPM.

I not sure brushed motor ESC has governor mode or not. Governor mode ESC is normally seen in brushless motor type of ESC.

EDIT:
I doubt brushed motor ESC has governor because there is no way for the ESC to read back the "Back EMF" from the motor to indicate the motor current running RPM. For Brushless motor, there are 3 wires to the motor. When 2 wire are energized, the 3rd wire (and with either one of the wire) can be read back because there is a voltage generated by the coil moving across the magnet.

SH

[pizza]

turnigy plush 12A esc. i do not think there is governor mode. how to i do PID control this way?

[Super-Hornet]

easiest way is to change your ESC to the one that has Governor mode.

SH

[007XerT]

Turnigy kforce or hobbywing platinum should have