User Manual

Note on using
filtered PWM
in Analog
Mode
If you are using a
filtered PWM signal from a microcontroller to generate the analog voltage, an R-C filter with
component values 10k ohms and at least .1uf is recommended as shown in Figure 4.1. This will
provide a fast response to changes in duty cycle, and is suitable for PWM rates of 20+kHz.
Using a larger value filter capacitor such as 47uf (Figure 4.2) will result in smoother motor
operation and greater efficiency. However, the transient response will be slower. This extra
capacitance is strongly recommended when using slower PWM frequencies – as low as 1kHz.
Tweaking the value of the capacitor to suit your individual needs is safe way to optimize your
robot’s performance.
Figure 4.1: Fast filtering Figure 4.2: Very smooth filtering