Uninterrupted hot swap Lipo battery with other DC source.

[kamondelious]

I've heard that you can reset the AX-12's in software when they stop working, by disabling and then re-enabling torque. I haven't tried this myself yet, so I can't say for certain that it works.

- Jon

I tested this out tonight. The max torque gets set to 0, which is why you "lose" movement. All you need to do is set the max torque on the AX-12 in order to regain control of it. You probably want to check the current position, load & temp before doing so, maybe even set a new goal position, as the AX-12 will go straight to it's goal position once max torque is reset.

Cheers!

[billyzelsnack]

Oh excellent. I was just fiddling with torque enable.

[Robert]

Is there some big problem with just using a pair of diodes? Just size the diodes appropriately to handle the current demand, while still having an acceptable voltage drop.

[billyzelsnack]

The diodes prevent the power sources from attempting to "charge" each other?

[JonHylands]

Yes, there is a problem with using Diodes. The voltage drop can be a significant problem in some circumstances. In our Brainbot robot, using a Diode pair (with 0.4 volt drop) has a noticable effect on available battery capacity. It also wastes power through heat.

The most annoying problem, though, is you can't use a wall power supply properly. Most 12 volt battery packs have a fully charged voltage somewhat higher than 12.0 volts. I have a 17 amp 12 volt wall power supply that I use to power Brainbot while it is on the bench. When I use that, I have to unplug all the batteries, because the diode pair chooses the source that is a higher voltage rather than the source I "want" it to choose.

My aux. power board (which is now available) solves all of these issues...

- Jon

[abachrac]

Jon, did you complete the power board that you were talking about?

I would be interested in purchasing one, but have not been able to find a link.

thanks!

[msprague]

I haven't been able to find a link to Jon's board either, but I did run across this when looks interesting:
http://www.mini-box.com/Y-PWR-Hot-Sw...ing-Controller

michael

[billyzelsnack]

That looks very interesting.

[tician]

Not sure if I'd buy one, but here is Jon's board.

[abachrac]

I haven't been able to find a link to Jon's board either, but I did run across this when looks interesting:
http://www.mini-box.com/Y-PWR-Hot-Sw...ing-Controller

michael

thanks for the info! That looks very useful!!