After finishing the basic wiring, we thought we should test if everything lights up correctly. Turn on the robot and BOOM! A muffled explosion and a smell of peanut butter. Turns out one of our Talon SRs blew up. We thought it was the internal capacitor and after searching a bit, we found that more people recognized the same peanut butter smell, which confirms our theory.
Peanut butter? People think it strange that I associate the smell of burning resin flux with home (my dad was an avid ham radio builder and operator), but I have never associated the smell of a shorted electrolyte with anything I would even remotely want to eat.
Was that one of the Talons that came in the KoP? If not, what year did you buy them? Were they connected correctly when you turned the robot on?
We had one of our KOP Talon’s from this year, that blew about 10 seconds after we turned power on for the first time. We check wiring, all 3 inches of it back to the PDP, was fine. So I decide to look into it, and found that the capacitor was installed backwards.
Capacitors this size have cut marks on the top to open to allow venting in case of over voltage, or reverse voltage. With this capacitor’s top up againts the heatsink, these vent couldn’t pop up and open, so the cap blew out the side wall.
Those remind me of Igor Pravagada, who spent many years experimenting with ways to filter High Voltage AC with polarized electrolytic capacitors. He is credited as the inventor of the electronic confetti generator.
Found a capacitor to replaced the one in our blown Talon.
UHE1V102MHD6 - Digikey has stock (FIRST Supplier!!!) Their stock # 493-1589-ND
I have been running this repaired Talon all morning and have had no problems.
Is that repair first legal?
Yes, per R55-M.
R55:
The Driver Station software, roboRIO, Power Distribution Panel, Pneumatics Control Modules, Voltage Regulator Modules, RSL, 120A breaker, motor controllers, relay modules, Wireless Bridge, and batteries shall not be tampered with, modified, or adjusted
in any way (tampering includes drilling, cutting, machining, rewiring, disassembling, etc.), with the following exceptions:
…]
M. Devices may be repaired, provided the performance and specifications of the device after the repair are identical to those before the repair.
That said, I don’t think I would personally use it on a competition robot… Maybe a Practice or parade bot, though.