Thread: 12V vs 13.8V?
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Old 10-06-2010, 02:13 PM
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MrB (Simon)
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Quote:
Originally Posted by Steffen View Post
While I agree that some protection should be offered (there are always things that can go wrong, and doubly so in the dark), you have to keep in mind that a protective (silicon) diode causes a 0.7V drop in voltage. This means your car battery powered scope mount will stop working 0.7V sooner as the car battery discharges. Depending on the minimum voltage the mount needs to operate this can be a considerable amount of battery time you're losing.

Cheers
Steffen.
True, tho many of the fast diodes these days have forward bias of only 0.2 to 0.4v.
Even so, thats why I mentioned the 50 cent(maybe a dollar worst case) P-ch MOSFET, virtualy zero voltage drop reverse polarity protection.
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