User Manual

RoboClaw Series

Brushed DC Motor Controllers

RoboClaw Series User Manual

BASICMICRO

Regenerative Voltage Clamping

Voltage Clamp

When using power supplies regenerative voltage spikes will need to be dissipated. This can be

done with a simple circuit shown below and using a V-Clamp pin to activate it. A solid state

switch (Q1) and large wattage resistor (R3) are required. The regenerative voltage will be

dissipated as heat. An example of a large resistor would be in the range of 10 Ohms at 50 watts

for small motors and down to 1 Ohms or lower for larger motors. 50 watts will likely cover most

situation smaller wattage resistor may work.

Voltage Clamp Circuit

Wire the circuit as shown below. Q1 should be a 3V logic level MOSFET. An example would be

BUK965R8. Which is rated to a maximum voltage of 100VDC. You may need to change the

MOSFET used based on the application. R2 (10K) will keep the MOSFET o when not in use. R3

will need to be adjusted based on the initial test results. Start with a 10 Ohms 50 Watt. If after

testing the voltage spike is still too great reduce the resistor to a 5 Ohms and so on. For model

specic pinout information please refer to the data sheet for the model being used.

Motor 1

Motor 2

M1A

M1B

M2B

M2A

ROBOCLAW

B-

B+

Battery

SW1

B- B+