220 pro plus waterproofing

[dmitry100]

Yea but going slower = less amps and less voltage right? I normally like to make a few rounds at a slower speed (partial throttle?) so that it cools the boat down after a speed run... Should I not be doing this? Better to let it sit still to cool off for a few seconds, rather than going partial throttle in this case to cool it down?

I figured partial throttle is like a normal thing lol.

[tlandauer]

Amp draw can go up or down when there are sudden changes in the water, speed change itself and the hull's attitude all affect the current draw. Data log will show the current draw goes higher when the boat is turning even though the driver maintained same throttle position. Partial throttle is giving command to the motor to work less and it will seek less current, but the FETS are working just as hard if not harder to govern that partial throttle command.
Note that slower speed doesn't mean the ESC is giving less voltage to the motor. Neither the ESC nor the motor see lower voltage just because the RPM is lower.
It is often a misconception: voltage does not kill the ESC, it is either the constant high amp draw or extreme spikes that produce heat that kills the ESC.
I have seen SAW racers do a bit, they coast carefully after an one-way run and time it to turn around for the other direction. They are just trying to not add extra heat during this turn around rather than cooling off. ( It may, however) Mind you when I say they coast it is very slow speed and gentle on the throttle. And the distance is short, just a U turn so to speak, if you want to chill it in slow motion, consider this: the slower speed is not going to pick up enough water flow, so it is in a way self defeating.
just my $.02....

[tlandauer]

From Wiki:
"Regardless of the type used, an ESC interprets control information not as mechanical motion as would be the case of a servo, but rather in a way that varies the switching rate of a network of field effect transistors, or FETs. The rapid switching of the transistors is what causes the motor itself to emit its characteristic high-pitched whine, especially noticeable at lower speeds. It also allows much smoother and more precise variation of motor speed in a far more efficient manner than the mechanical type with a resistive coil and moving arm once in common use.

Most modern ESCs incorporate a battery eliminator circuit (or BEC) to regulate voltage for the receiver, removing the need for separate receiver batteries. BECs are usually either linear or switched mode voltage regulators.

DC ESCs in the broader sense are PWM controllers for electric motors. The ESC generally accepts a nominal 50 Hz PWM servo input signal whose pulse width varies from 1 ms to 2 ms. When supplied with a 1 ms width pulse at 50 Hz, the ESC responds by turning off the DC motor attached to its output. A 1.5 ms pulse-width input signal drives the motor at approximately half-speed. When presented with 2.0 ms input signal, the motor runs at full speed.
Brushless ESC
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The correct phase varies with the motor rotation, which is to be taken into account by the ESC: Usually, back EMF from the motor is used to detect this rotation, but variations exist that use magnetic (Hall Effect) or optical detectors. Computer-programmable speed controls generally have user-specified options which allow setting low voltage cut-off limits, timing, acceleration, braking and direction of rotation. Reversing the motor's direction may also be accomplished by switching any two of the three leads from the ESC to the motor."


In a nut shell, the ESC is like a switch, it controls the motor's RMP by switching it on and off .