In the Roboclaw 2x30,
How important is the diode across the power switch?
I’m making a second robotic elephant …using pairs of American Machinery Motors from Oregon with some Roboclaw 2x30’s
(for position control with potentiometers connected)
I’ve made 1 elephant before with Vantec controllers,
AnD a cow with a couple Roboclaw 2x60’s
(It’s always tough to figure out the motor amperages but I think i’ve had a 15A fuse pop once or twice …all other fuses were 10A and never popped.)
(Batteries are 20 Amps)
The way I LIKE to wire power is with a double-pole switch cutting off +AND - completely with no diodes or resistors.
When I used the Roboclaw 2x60’s I Called to ask about the diode
…and i don’t ‘Remember’ wiring a diode
…so i’m hoping the answer is they should be fine without it.
Chris
Hello, Chris.
Keep in mind this is a public forum, so we generally do not recommend posting personal contact information (e.g. email address) like you had in your signature. I edited your post to remove that this time.
Whether or not you need a bypass diode depends on several specific aspects of your system like the supply voltage, motor characteristics, and desired acceleration/deceleration rates. However, whether you use a double-pole switch versus a more typical single-pole switch is probably an irrelevant detail since the main point of the diode is to handle voltage spikes from regenerative braking in a good way. I recommend reviewing this Motor Controller Hardware Precautions article here for more information.
In general, adding a bypass diode should be an easy modification and makes it much less likely for you to damage your controller, so I recommend it. However, you could check to see how much your system might need the diode by monitoring it with an oscilloscope so you can see what kind of voltage spikes your motor actually induces during operation. If you decide to do that, I suggest you start with a low supply voltage and low acceleration/deceleration rates to be safe.
- Patrick
