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View Full Version : How to bypass/replace the VRM


HolyRedPenguin
18-05-2016, 15:41
Our team is trying to restore one of our old robots with the new electronics, but we do not have a VRM. Are there any ways to bypass or replace this?

Knufire
18-05-2016, 15:43
Our team is trying to restore one of our old robots with the new electronics, but we do not have a VRM. Are there any ways to bypass or replace this?

You might have one of the old 12V to 5V buck converters from the old control system. If all you needed the VRM for was to power the radio, this should be fine.

Look at the 12V to 5V converter on this page: https://wpilib.screenstepslive.com/s/3120/m/8559/l/90113-2014-frc-control-system-hardware-overview#!prettyPhoto

If you don't have one lying around, there are similar ones on AndyMark and Amazon.

Greg Needel
18-05-2016, 15:49
You might have one of the old 12V to 5V buck converters from the old control system. If all you needed the VRM for was to power the radio, this should be fine.

Look at the 12V to 5V converter on this page: https://wpilib.screenstepslive.com/s/3120/m/8559/l/90113-2014-frc-control-system-hardware-overview#!prettyPhoto

If you don't have one lying around, there are similar ones on AndyMark and Amazon.


If you are using the old D-link radio this is fine, but the new open mesh radio is 12v source.

You could use the old radio with no issues if just for practice.

If you wanted to use the new radio, you could buy a boost converter that will give you a constant 12volts once adjusted.
like this one. http://www.amazon.com/DROK-Converter-Adjustable-Regulator-Transformer/dp/B00J03PBW0

timytamy
19-05-2016, 02:26
As others have said, try to use the older regulators if you can.

If it's a cRIO era robot with a PDB, AND you're not planning on working it too hard then you can potentially use the regulated outputs on the bottom of the PDB. This should work absolutely fine until you start moving. However if you've got a lot of heavy current draw motors, then you can potentially brown-out and lose power to these outputs. Use at your own risk.

Anecdotally, for a reasonably geared tank drive with 2-4 CIMs, I haven't had a problem with this "hack".