[CinquinoEVZ]

Looking at a Sevcon dc dc converter, what happens if you don't wire the enable pin?

 

[remy_martian]

I'm guessing it gets disabled, which is what you'd want if the enable wire breaks

 

[cricketo]

I have one of those 5-pin dc-dc converters. If enable pin isn't energized, you get no output

 

[CinquinoEVZ]

I have one of those 5-pin dc-dc converters. If enable pin isn't energized, you get no output

Now makes sense... so basically it needs a wire from the ignition or take some energy from another line that gets a live signal after the ignition goes on.

 

[cricketo]

Correct, wiring it to ignition is a good way to do it. Enable pin takes very little current, so key switch can handle it, as opposed to energizing the input of the DC-DC, which would require another relay in the 10A range for 48V.