+ User Manual
For the original BeBoPr boards it was recommended to mount some extra bulk capacitance
over the input pins of J18, as shown in illustration 10.
Use a good quality capacitor to handle these recurring current peaks (470 µF/35V, Nichicon nr.
UPW1V471MPD) has proven to work at stepper voltages up to 24 Volts. A smaller capacity will
do, but don't lower the working voltage!
The + has a single 220uF electrolytic and two 10uF ceramic capacitors on board. So no
external capacitor should be needed.
version 1.4.9 (09/04/14)
page 29
Warning:
This carrier board uses low-ESR ceramic capacitors, which makes it susceptible to
, especially when using power leads longer than a few inches.
Under the right conditions, these spikes can exceed the 45 V maximum voltage rating for the
DRV8825 and permanently damage the board, even when the motor supply voltage is as low
as 12 V. One way to protect the driver from such spikes is to put a large (at least 47 µF)
electrolytic capacitor across motor power (VMOT) and ground somewhere close to the board.
Illustration 10 - Extra capacitor to protect Pololu modules