Re: Dead PET 2001

Re: Dead PET 2001

From: Marko Mäkelä <msmakela_at_gmail.com>
Date: Tue, 11 Aug 2009 16:43:49 +0300
Message-ID: <20090811134349.GD14449@x60s>
On Tue, Aug 11, 2009 at 09:31:20PM +0900, Philip Lord wrote:
> Update:
> With the red leads detached from the capacitor I tested the voltages  
> again this evening.
> Where as before I was getting over 8VDC, now I'm only getting 0.5VDC on 
> the cathode side of the diodes...very strange. I wish I knew what was 
> going on.
> Maybe it's time to start by removing the diodes and testing them.

It of course suffices to desolder just one end of each diode.  I don't have
much experience in analog electronics, but I can imagine that open-circuit
or short-circuit diodes in the bridge could cause all sorts of failures.

For what it is worth, a MOSFET rectifier bridge that I built for my bicycle
failed in a similar way after it apparently got some over-voltage from the
dynamo.  Luckily there was a Schottky diode between the MOSFET bridge and
the rest of the circuit, so that everything else (including the mobile phone)
was unaffected.  The circuit would only deliver some .5 or 1.5 volts instead
of the designed 5 volts.

	Marko

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Received on 2009-08-11 16:05:40

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