November 26, 2024, 12:03:00 AM

repairing rev C boards

Started by BJFreeman, March 01, 2013, 10:15:18 PM

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BJFreeman

I got 2 rev C boards that worked fine on USB till I hooked them up to my 12v house batteries in my RV.
they worked for about a week then died.
The power led shows but not the other leds.
so I am starting my trouble shooting.
first question the FET1 symbol shows it as a depletion p channel but datasheet says it is a enchanced P channel.  is the part number wrong or the symbol
Fulltimer since 89

LubOlimex

Hey BJ,

The FET1 you ask about should be P-channel MOS with Rds not more than 0.1 and Gate-source-threshold-voltage not more than 1.5V max.

Regards,
Lub/OLIMEX
Technical support and documentation manager at Olimex