Vex Bench Power Supply

Something I made over the summer :slight_smile:

Outputs 8.5V @ 18A max, easily supports 2 fully loaded robots and 4 remotes. Only 2 output connectors are shown here but there should be 6.

I need to add 9.1v zener clamps and fuses to guard against overvoltage and overcurrent soon… and perhaps a cooling fan too.

So we had a couple of groups of students working on robots for almost 9 hours a day, programming and testing, practicing tecnhiques and trying out new methods. Each group could use up to sets of batteries a day, and 3 teams would use 9. At the end we have a box containing all the old, weak batteries (after a hundered or so cycles?) and a couple of blown chargers. Wall warts wouldn’t work, they had to provide at least 4A for each robot to cater for maximum loading and overheads. Hopefully this power box would last much longer.

Nice job, you should produce those and sell them.

I agree. We are constantally looking for fresh batteries.

I’m located in Asia, shipping costs to the states probably won’t justify for it (actually I’m having problems helping the schools I’m mentoring obtain Vex parts too :frowning: )

This can be relatively easily made by most experienced engineers. It is essentially an 8.5V switched power supply with a sufficiently high current rating (does RadioShack or some local electronics store sell similar ones?)

Get a bag of plugs, wires, fuses, an LED of your favorite color and a plastic (for safety) box, and you’re all set. Perhaps even throw in a digital voltage and current draw LED display if you’re keen.

How risky is it? Depends how much safety enhancements are added, such as fuses, voltage caps, etc.

A neater idea would be to integrate support fast-charging of Vex batteries, draining of batteries, battery load testing and also battery conditioning - though it would be more of a nice-to-have rather than a practical idea :stuck_out_tongue: