I have a fairly simple pcb board I designed.
12v power goes thru a diode for reverse polarity protection.
Then the ground and 12v go into a buck converter to drop down to the second voltage or 5.0v.
From here goes to a 470 microfarid capacitor
Then to a microprocessor,lcd and a small hobby style servo.
Today on some units the microprocessor is damaged if they hook up 12v to the 5v wire and some I believe might be getting higher voltage as a guess by moving the servo when off. Either way I need to at least blow the fuse or protect the microprocessor/lcd from a over voltage.
This condition doesn’t happen often so want to keep the design minimal as my project has a small footprint. Can a simple zener diode be put across the same spot as the capacitor with 5.1v so if it exceeds would dump to ground. Would I need a additional resistor or sizing calculation to ensure the fuse blows when the condition is met.
should I redesign the board with something better. Trying to keep cost down and size down but want it to avoid hitting the upper side of 5.5v to keep microprocessor from cooking.
Thanks. I’ll see how to get a schematic uploaded as well.
12v power goes thru a diode for reverse polarity protection.
Then the ground and 12v go into a buck converter to drop down to the second voltage or 5.0v.
From here goes to a 470 microfarid capacitor
Then to a microprocessor,lcd and a small hobby style servo.
Today on some units the microprocessor is damaged if they hook up 12v to the 5v wire and some I believe might be getting higher voltage as a guess by moving the servo when off. Either way I need to at least blow the fuse or protect the microprocessor/lcd from a over voltage.
This condition doesn’t happen often so want to keep the design minimal as my project has a small footprint. Can a simple zener diode be put across the same spot as the capacitor with 5.1v so if it exceeds would dump to ground. Would I need a additional resistor or sizing calculation to ensure the fuse blows when the condition is met.
should I redesign the board with something better. Trying to keep cost down and size down but want it to avoid hitting the upper side of 5.5v to keep microprocessor from cooking.
Thanks. I’ll see how to get a schematic uploaded as well.