- Sun Nov 24, 2013 11:14 am
#165920
Hi,
I have various PCBs on my robot each doing a function (I'm planning to design 1, as a mother board but still couldn't find time). When I connect them to the battery, I always see sparkles. Some questions:
1. Why we have sparkles there? (one PCB is my DIY Arduino, has a 7805 to step-down to +5, and the battery is 12v @ 7amp (acid) and I see those sparkles when connecting it, wondering about over-current in first second?)
2. What if we have this scenario:
a. suppose I have PCB-A and PCB-B which must have a ground connection
b. the A consumes +3v but B consumes +5v, and GND already is connected between them
c. I use alligators to connect both of them to the batter
d. once, starting to connect them to the battery I first connect + from the B and (say, by mistake) - from A
result: will 5v pass via A and is there possibility to hurt A? If so, what to do to avoid possibility of such a scenario please?
Thank you.
I have various PCBs on my robot each doing a function (I'm planning to design 1, as a mother board but still couldn't find time). When I connect them to the battery, I always see sparkles. Some questions:
1. Why we have sparkles there? (one PCB is my DIY Arduino, has a 7805 to step-down to +5, and the battery is 12v @ 7amp (acid) and I see those sparkles when connecting it, wondering about over-current in first second?)
2. What if we have this scenario:
a. suppose I have PCB-A and PCB-B which must have a ground connection
b. the A consumes +3v but B consumes +5v, and GND already is connected between them
c. I use alligators to connect both of them to the batter
d. once, starting to connect them to the battery I first connect + from the B and (say, by mistake) - from A
result: will 5v pass via A and is there possibility to hurt A? If so, what to do to avoid possibility of such a scenario please?
Thank you.