Hello all,

 For those of you who knew about my little I2C problem that I had, I have
officially given up on it until I receive my new sensors from Microchip - in
which case I will try again :-) Anyway, working on the other parts of my
project, I started on getting my MAX787 5V SMPS regulator working. It's a very
simple connection, so it seems, according to the data sheet on maxim's web
site (http://www.maxim-ic.com/quick_view2.cfm?qv_pk=1271). I am using their
EXACT circuit, and getting a nice solid +5V output. The problem is at the
input from the rectifier. Basically, I have a transformer that goes to a full
wave rectifier, and then the positive part of the rectifier is fed into the
input of the regulator. As soon as I connect the input of the regulator to the
output of the rectifier, the voltage at the input jumps up to ~45V. Without
the regulator connected, the voltage at the output of the rectifier holds at
~25V. Checking the negative side, with no regulator connected, it gives a -
25V - so it's symmetric, which it seems fine. But as soon as I connect the
regulator, when the positive swings up to 45, the negative becomes about -5.
How come the voltage swings like that? Is this normal? Is there anyway I can
control it?

Thank you,

Jai



----------------------------------------
This mail sent through www.mywaterloo.ca

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.