Schematic

Brushless Motor Connections and Operation

98 Advanced Digital Motor Controller User Manual V1.8, August 28, 2017

Sensorless Conﬁguration and Calibration

The controller’s default conﬁguration will typically work with any motor. However, faster and

more consistent motor startup will be achieved by performing these setup and calibration steps:

1. Make sure the battery volts and if possible the maximum load on the motor is set. If

either changes the procedure will need to be repeated.

2. Conﬁgure motor channels as sensorless.

3. Set motor command 10 or -10 and check if the motor starts and rotates smoothly

when using the default setting. If not modify Sensorless Start-Up Power (SSP) accord-

ingly. Higher the motor friction, the higher the value of SSP should be.

4. Type on console %clmod 4 (for channels 1). This will cause the controller to enter the

sensorless calibration mode.

5. Set Motor Command 10 or -10 and wait until the rotation of the motor becomes

smooth and stable.

6. Wait for a couple of seconds and stop the motor.

7. Monitor the Hall Speed with motor command 10 and -10. Make sure the speed is the

same in both directions symmetrical. If not then choose as last the motor command

which gives the smallest speed.

8. Type on console %clmod 0 to exit the calibration mode

9. Type on console %eesav, in order to save the value on ﬂash.

Startup should be quicker and more efﬁcient after these steps. Calibration values can be

viewed, and manually adjusted if needed, using the SST conﬁguration.

Sensorless brushless motors only require their 3 wires to be connected to the controller’s

U, V and W terminals. The wires can be connected in any order. If the motor spins in the

opposite direction than the desired one, simply invert any two motor wires. It is also pos-

sible to use the MDIR Motor Direction conﬁguration parameter.

Verifying Commutation Timing

In trapezoidal modes, with an oscilloscope it is possible to verify that the commutation,

either in Hall sensors or sensorless mode, is happening at the optimal time. On a mo-

tor driven by the motor controller, place a probe between ground and any of the motor

phases. Verify that the voltage looks like the shape on the ﬁgure 8-6. Look for symmetrical

ramps on the left and right.

T TT/2 T/2T/2 T/2T

Figure 8-6. Ground to Phase voltage waveform on motor with correct commutation

An alternate method is to run the motor in the forward and then in the reverse direction.

Verify that for a give command level in open loop, the motor reaches the identical speed

and consumes the same amount of current.