Unfortunately, the wires coming out of these are ridiculously small. We had to use a knife to strip them, and even then we had no way of wiring them into the PDB. We tried to crimp them into inline connectors along with some higher gauge wires to go directly into the PDB. However, that did not work, because the small wire was too fragile to crimp. We tried twisting them to the higher gauge wire directly and they would not turn on. How have your teams wired them?
We carefully stripped them and inserted them into the PD Board. If you strip it the right length and put it it right, it should stay in like any other wire. Another idea that I just came up with is to flatten a larger stranded wire, melt some solder onto it, and place the small wire into it, then cover with electrical tape.
Melt the solder holding the small wires to the ring light with a soldering iron, take them out then use the existing solder to attach larger wires. It worked for us.
That’s not a bad idea… Might have to try it myself… For now though, we used some of those terminal blocks that we seem to have ever so many of to connect the light to some heavier wire. (which then connected to the PD board)
I don’t know if this has happened to any other team, but our ring light shorted somewhere along the skinny wires they shipped with and there was a small electrical fire (while it was on our robot). Although we had it soldered to a thicker cable (was heavily covered up by electrical tape ) that went to the PD board, we’re sure it happened somewhere along the skinny cable because the shorting happened somewhere along the upper half of the wire (which literally melted away).
We got rid of all the wires and soldered 12 gauge wire directly the ring itself and power comes from the PD board. The light glitched a bit at first (one of the LED’s stopped working) but came back to life the following day. :ahh:
Whatever you do, make sure the wires that connect to the ring light don’t touch each other!
-btw one of our mentors thought this was weird because a breaker should trip when something shorts, but that didn’t happen. maybe because our shorting issue went away after the wire melted? any answers to this o.O?-
The wire on the ring lights is much too small to be adequately protected by a 20A breaker. It likely burned through and eliminated the short before the breaker could trip.
You should never need a knife to strip wires. The link you give doesn’t take specs for the wire gauge, but I doubt it’s any more than 30AWG. You should look into getting some appropriately sized wire strippers. I personally prefer these, but there are plenty of good strippers out there. The only advice I’ll offer on that point is to not get an automatic stripper.
With regards to CRL’s post, it is very easy for thin wires to catch fire without tripping the breaker, simply because the current draw won’t trip it (as has already been pointed out). It’s hard to believe that the manufacturer would make such a mistake, but nonetheless, if you do resolder the wires (which is generally simpler and neater than soldering the existing wires to thicker ones), check for shorts before you power it, or power it away from the robot to make sure there are no shorts.
A resistor would limit current and be more likely to prevent a fire than induce one. Just because the fuse on the circuit is for 20A doesn’t mean the circuit will draw 20A.
The insulation on the ring lights is so soft we stripped them with a fingernail!! I would NOT solder them as that insulation will melt quickly. We stripped them, folded the bare wire over itself so it is thicker, crimped it in a butt splice, crimped the other end to some 22AWG cable and ran it to the M+ and M- terminals of a spike so we can turn it on and off. The GND and 12V terminals of the spike go to the PD board.
For testing, I connected the ring light’s thin wires to 20 gauge conductors from a Spike using a short section of the green terminal strip from the Kit of Parts.
Today, as the final wire routing is set on the robot, I plan to replace the existing wires entirely and use a four-conductor cable to bring power to both the LEDs and the camera itself.
What I’d really like to do is to get my hands on a supply of Ethernet jacks and mess around with tunneling power through a single patch cable from the electronics box to the camera, but that’s not going to happen this year.
No, that’s not what I mean. I don’t want to do anything so expensive and heavy and intrinsically safe as POE. I just want to employ the unused four wires in an 8-wire ethernet patch cable to carry 5 volts to power the camera and a switched 12 volt circuit to power the ring of LEDs.
Right, but there are two problems to deal with for the application I was considering. First, I want to be able to turn the 12 volt circuit on and off under program control. Second, and rather more important at this time, is that every POE injector I’ve ever seen uses AC power from a wall outlet. Those are understandably rare on an FRC robot. :rolleyes:
. Works much better in the P…