RhinoRampage
Newbie level 2
Hi, I'm hoping someone with a bit more electronics experience can help resolve some paranoia. Here's the situation:
I have a machine which has several microcontrollers on a CAN bus. These micro's have some special power circuitry (using capacitors etc.) such that when they are powered down, the voltage ramps down in a particular manner so that values can be saved to EEPROM, etc.
A few weeks ago, there may have been a short between either CANH, CANL, or Shield, since these wires were left dangling out of the machine while it was on. After noticing the wires, the hazardous situation was removed. Fortunately there was no evidence of a short, and the CAN bus is still working perfectly.
Soon after that we started having problems with the power circuits controlling the voltage drop on power off for a couple of the microcontrollers, where the voltage is now dropping too rapidly. I'm wondering if the two events are related?
I'm guessing they aren't, since if there was a short, and if the CAN bus was not designed to protect against shorts, there would have been high current going through the micro. This would mean the micro would also be fried. I can't think of any way that the power circuitry would be affected given that the micro's are fine.
I'm thinking this is likely to be a co-incidence. Thoughts?
---------- Post added at 05:59 ---------- Previous post was at 05:58 ----------
^^ Also, I'd like to give more information about the actual components used but I can't actually get to the board for closer inspection (as it's firmly encased and the manufacturer doesn't give out that kind of info)
I have a machine which has several microcontrollers on a CAN bus. These micro's have some special power circuitry (using capacitors etc.) such that when they are powered down, the voltage ramps down in a particular manner so that values can be saved to EEPROM, etc.
A few weeks ago, there may have been a short between either CANH, CANL, or Shield, since these wires were left dangling out of the machine while it was on. After noticing the wires, the hazardous situation was removed. Fortunately there was no evidence of a short, and the CAN bus is still working perfectly.
Soon after that we started having problems with the power circuits controlling the voltage drop on power off for a couple of the microcontrollers, where the voltage is now dropping too rapidly. I'm wondering if the two events are related?
I'm guessing they aren't, since if there was a short, and if the CAN bus was not designed to protect against shorts, there would have been high current going through the micro. This would mean the micro would also be fried. I can't think of any way that the power circuitry would be affected given that the micro's are fine.
I'm thinking this is likely to be a co-incidence. Thoughts?
---------- Post added at 05:59 ---------- Previous post was at 05:58 ----------
^^ Also, I'd like to give more information about the actual components used but I can't actually get to the board for closer inspection (as it's firmly encased and the manufacturer doesn't give out that kind of info)
