More than one power distribution board

[Al Skierkiewicz]

Originally Posted by zbrozek

I'm not sure what the per-unit cost targets are, but I tend to use electronic overcurrent circuits.

Have you seen something that can protect 40 amp wiring and still function at the 130 amp stall of a CIM for a short period of time?

[zbrozek]

Originally Posted by Al Skierkiewicz

Have you seen something that can protect 40 amp wiring and still function at the 130 amp stall of a CIM for a short period of time?

Yup. Infineon makes excellent FETs, and Linear Technology makes excellent surge protection control ICs that drive them. BOM cost is a little high at about $8/channel in qty 1 from Digikey (so assume 1/10th that or less at any decent scale). They have capacitors to set the allowable overcurrent time. One of the circuits I built at work hard limits at 180A and is intended for 60A continuous. Consumes a little less than a square inch.

[nuttle]

We use this set of tools from WAGO -- they seem to work much better than a screwdriver and fit all connectors of this type used in FRC.

[martin417]

This thread has wandered a good bit from the OP's question which was:

Is it legal to have more than one power distribution board?

In 2012, our vision tracking relied on a consistent light color and intensity. Whenever we shot and the motors had to work to spin up the shooter, or when we drove hard, the LEDs would dim and we lost tracking. So on Friday night, we dismantled an extra PD (removed the blue plastic case, and most of the WAGO connectors), then connected it as a load to the other PD, then used the boosted 12V power supply (normally used for the WiFi bridge) to supply the LEDs. That way, even when the voltage dropped, the LEDs remained at a constant brightness.

Since the PD was modified, and connected to a circuit breaker, it was considered a custom circuit, and therefore legal. (yes, we did get re-inspected).

[Al Skierkiewicz]

Originally Posted by zbrozek

Yup. Infineon makes excellent FETs, and Linear Technology makes excellent surge protection control ICs that drive them. BOM cost is a little high at about $8/channel in qty 1 from Digikey (so assume 1/10th that or less at any decent scale). They have capacitors to set the allowable overcurrent time. One of the circuits I built at work hard limits at 180A and is intended for 60A continuous. Consumes a little less than a square inch.

Part numbers and links please.

[apalrd]

So everyone seems to generally like the big WAGO's on the PD board.

Does anyone else totally hate the little white ones? they're used for power to the cRio breakouts and the radio power out on the PD board. My electrical student has a really really hard time doing them, so usually I do all of them for her.

[Nirvash]

Originally Posted by apalrd

So everyone seems to generally like the big WAGO's on the PD board.

Does anyone else totally hate the little white ones? they're used for power to the cRio breakouts and the radio power out on the PD board. My electrical student has a really really hard time doing them, so usually I do all of them for her.

I don't like them, after a while you get used to working with them, but I have seen a few that have broken apart from someone putting too much force on the screwdriver. Also, they are a pain if you want to attach a wire when the connector is free.

[Alan Anderson]

Originally Posted by apalrd

So everyone seems to generally like the big WAGO's on the PD board.

Does anyone else totally hate the little white ones?

If you don't have the right tool, they're certainly hard to use. On the other hand, if you do have the right tool, they're easy. We used a grinding wheel to make a "shaved" Wago tool, and another small similarly shaved screwdriver, that fit them fine.

The only Wago connection that I truly wish would go away is the one on the PDB's dedicated 5 volt output. I've never found a good tool to fit it. The best thing I've found so far is a scribe with a straight tip.

[Joe Ross]

The 2015 control system continues to use the larger Wago connectors on the PDB. Everything else uses tool-less push-in connectors from Weidmuller. These are the same connectors used on the 2CAN. They require a little practice to get the wire stripped to the correct length, and the wire must fairly straight (too many insertions and removals may require starting over).

[zbrozek]

Originally Posted by Al Skierkiewicz

Part numbers and links please.

Glad to help!

First hit shows the interesting product line from Linear

First hit shows the interesting product line from Infineon

More specifically, the LTC4364 and IPT004N03L are attractive.

EDIT:
And for the low-current channels, TI makes a pretty great device.