John Weston wrote:
Dennis Pogson, in article HmLYf.12303$NN4.1853@newsfe7-
win.ntli.net, says...


The laptop's power brick plus an inverter is far better at dealing
with the voltage "spikes" that an alternator can put out, as I found
to my cost a couple of years ago, blowing the system board using one
of these DC-DC converters.

Interesting observation, Dennis. I haven't had this
experience in either boat or car so I'll have to "look into
it". It suggests bad design because why didn't a similar
spike kill or ride-through the Inverter? The "buck
converter" design should have a similar transformer isolating
input and output as that in the inverter - unless it is a
cheap transformerless design... Perhaps the solution is to
get rid of the spike before it enters the electronics with an
additional filter before the input?? At least that would be
less power wasting.

There are probably cheap DC-DC converters which can't handle spikes, and
more expensive ones that can. The ones sold here in the UK for around £12
look altogether too simple to me. The one referenced by Hanz looks a
different matter altogether. I don't think the one bad experience I had is
sufficient to condemn all such devices, but a new system board these days is
as expensive as a new laptop, so my caution is understandable.

Running the laptop without the engine/alternator would probably be the
safest bet, but we all know crew members who will, as soon as the speed
drops below 2 knots, press the starter button!

Dennis.