[Dr_C2]

Edited to add this warning:

Please proceed to read this post only if you have a deep interest in brushless motors.

Three ways to drive a brushless motor (and of course there are more!):

1/ I’m familiar with Electronic Speed Controllers (ESC) as used for radio controlled aeroplanes and cars. These usually have a power lead for connection to a battery pack (typically a LiPo pack), a three wire connection to a receiver, and a three wire connection to the brushless motor. The control signal from the receiver is typically a pulse of 1-2mSec duration and a repetition rate of circa 50Hz. The pulse duration indicates throttle value (and when used also the brake value).

2/ Recent brushless motor developments and trials for analog slot cars appear to use a five terminal Electronic Commutator (Ecom). The input is two terminal and connects directly to the rails. The output is the three wire connection to the brushless motor. These typically use a simple analog track voltage as input as generated by a passive analog throttle controller or, in some cases, a PWM input that is generated within a transistorised throttle controller. And as mentioned earlier in this thread these Ecom/brushless combinations are delivering slotcar racing wins at national/international events. But so far this is only in the ‘analog’ slotcar world.

3/ What I am working on is neither. Hence I am referring to my device as a brushless motor ‘driver module’. This takes DC power from a digital decoder together with two addition digital signal lines which communicate throttle settings and brake settings. This is important for digital racing where both precise throttle control and adjustable braking are required. The output of course is the three wire connection onto the brushless motor. And, since my project uses sensored motors there is the additional requirement for interconnection of the motor’s sensor port.

I’ve already mentioned earlier my intended design point will use a two-board (or two-module) approach. These are the main decoder and the brushless motor drive module respectively. To keep the interconnection wiring harness to a minimum, the brushless motor driver module will be attached directly to the motor.

Hoping all of above is clear :)

c