Yea, I didn't understand the comment about a crowbar damaging components, crowbars are designed to protect the downstream components, and a fuse before the crowbar should protect the upstream components.

Maybe Ian0 could expand on this concern, I'm willing to learn something.

 

Yea, I didn't understand the comment about a crowbar damaging components, crowbars are designed to protect the downstream components, and a fuse before the crowbar should protect the upstream components.

Maybe Ian0 could expand on this concern, I'm willing to learn something.

Upstream was a buck regulator. Some deal with short circuits better than others. . . .

 

Upstream was a buck regulator. Some deal with short circuits better than others. . . .

Good point. I’ll need to play around with a resettable fuse or something to limit it.

Maybe I just move the buck converter and circuit protection to where they hook up power. Then only allow 5v everywhere else. Old design I did that. Keeps 12v out of the cables. Thanks for all the help. KISS engineering is my preferred method. Keep it simple….

 

Can you share what exactly is getting toasted? The NANO has a similar scheme as other Arduino boards.


Like the other boards the only way to cook anything is to apply a voltage in excess of 5 Volts to the 5 Volt pin. Each method of trying to make it foolproof will have good and bad points.

Ron

 

Good point. I’ll need to play around with a resettable fuse or something to limit it.

Maybe I just move the buck converter and circuit protection to where they hook up power. Then only allow 5v everywhere else. Old design I did that. Keeps 12v out of the cables. Thanks for all the help. KISS engineering is my preferred method. Keep it simple….

If you put any sort of fuse on the output of the buck regulator, then the regulator must be able to output enough current to trip/blow the fuse. Otherwise, when the crowbar is triggered, it will just go into current limit and stay there indefinitely at maximum output current warming up the crowbar thyristor.