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Hello Henry,<br>
<br>
Thank you for your input to the Demeter project. Thank you for the
input you provided to my personal address as well. I will compile all
the new input, form all the contributers, to a new document. Hope to
post it soon.<br>
<br>
Mr. Bakker, thank you for the interesting link to the LT application
note. The appendices might be even more interesting than the real
article... ;-)<br>
<br>
73 Jeroen<br>
<br>
Henry Vredegoor wrote:<br>
<blockquote cite="mid020801c7bcb3$546b6240$6402a8c0@Blues" type="cite">
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<div><font face="Arial" size="2"><span class="453194115-29062007">Hello
Jeroen, All,</span></font></div>
<div><font face="Arial" size="2"><span class="453194115-29062007"></span></font> </div>
<div><font face="Arial" size="2"><span class="453194115-29062007">As
to the question of if there should be a number of smaller boards or one
(or two) bigger boards, </span></font><font face="Arial" size="2"><span
class="453194115-29062007">I think it would be the best option if we
want optimal flexibility and scalability.</span></font></div>
<div><font face="Arial" size="2"><span class="453194115-29062007">On
the other hand a single board with all the different regulators and
control processor on it has the advantages of being compact and
the easier interconnections between them.</span></font></div>
<div><font face="Arial" size="2"><span class="453194115-29062007"></span></font> </div>
<div><font face="Arial" size="2"><span class="453194115-29062007">I
don't know what the aim is for the upper limit of the
currents/voltages/power for the different regulators planned for
Demeter and the resulting total dissipation that goes with these.</span></font></div>
<div><font face="Arial" size="2"><span class="453194115-29062007">I
could imagine that you would like to dissipate the heat to the outside
of the HPSDR enclosure using external heatsinks (avoiding noisy
ventilators)</span></font></div>
<div><font face="Arial" size="2"><span class="453194115-29062007"></span></font> </div>
<div><font face="Arial" size="2"><span class="453194115-29062007">All
that said. a number of questions/remarks that come to mind:</span></font></div>
<div><font face="Arial" size="2"><span class="453194115-29062007"></span></font> </div>
<div><font face="Arial" size="2"><span class="453194115-29062007"> -
Will these boards have external power devices that need to be mounted
off-board (e.g. the linear regulators)?</span></font></div>
<div><font face="Arial" size="2"><span class="453194115-29062007"><span
class="453194115-29062007"> - Could one scale up for more current?
(more power devices etc.), What about r<span class="453194115-29062007">egulators in
parallel for higher current?</span></span></span></font></div>
<font face="Arial"><span class="453194115-29062007"><span
class="453194115-29062007">
<div>
<div><font face="Arial" size="2"><span class="453194115-29062007"> - Could one
add more voltages (regulators)? </span></font></div>
<div><font face="Arial" size="2"><span class="453194115-29062007"> </span></font><font
face="Arial" size="2"><span class="453194115-29062007">-
Would separate boards give more options for EMI suppression (earthing,
shielding, mechanical) ?</span></font></div>
<div><font face="Arial" size="2"><span class="453194115-29062007"> -
Mechanical mounting </span></font></div>
<div><font face="Arial" size="2"><span class="453194115-29062007">
- Attached with their power devices directly to an (external)
heatsink? </span></font></div>
<div><font face="Arial" size="2"><span class="453194115-29062007">
Running<font face="Arial"><span class="453194115-29062007"><font
size="2"><span class="453194115-29062007"> longer wires to an external
power device on a heatsink is not a good idea</span>,<span
class="453194115-29062007"> especially not for a switcher... ;-)</span></font></span></font><font
face="Arial"><span class="453194115-29062007"><span
class="453194115-29062007"></span></span></font></span></font></div>
<div><font face="Arial" size="2"><span class="453194115-29062007"> -
Have a particular regulator as close as possible to the attached user
(e.g. a power amp)?</span></font></div>
<div><font face="Arial" size="2"><span class="453194115-29062007"> -
Scalability:</span></font></div>
<div><font face="Arial" size="2"><span class="453194115-29062007">
- With a linear regulator it is relatively easy to increase the output
current; you could have a low power board for a limited current and
scale up by adding </span></font><font face="Arial" size="2"><span
class="453194115-29062007">external power devices</span></font></div>
<div><font face="Arial" size="2"><span class="453194115-29062007">
- This is not the case with a switching regulator as far as I know.</span></font></div>
<div><font face="Arial" size="2"><span class="453194115-29062007">
This would require besides adding a more high power switcher device
also at least exchanging inductors and capacitors with higher power
versions and other C and L values?</span></font></div>
<div><font face="Arial" size="2"><span class="453194115-29062007"></span></font> </div>
<div><font face="Arial" size="2"><span class="453194115-29062007"><span
class="453194115-29062007">I think some of these aspects are good
reasons to have regulator board(s) to be separate ones?</span></span></font></div>
<div><font face="Arial" size="2"><span class="453194115-29062007"><span
class="453194115-29062007"></span></span></font> </div>
<div><font face="Arial" size="2"><span class="453194115-29062007"><span
class="453194115-29062007">I am aware of the fact that this makes the
internal wiring more difficult though..</span></span></font></div>
<div><font face="Arial" size="2"><span class="453194115-29062007"><span
class="453194115-29062007"></span></span></font><font face="Arial"
size="2"><span class="453194115-29062007"><span
class="453194115-29062007"></span></span></font> </div>
</div>
<div><font face="Arial" size="2"><span class="453194115-29062007"><span
class="453194115-29062007">The PSU controller board containing the
microcontroller I think should be a separate board anyway.</span></span></font></div>
<div><font face="Arial" size="2"><span class="453194115-29062007"><span
class="453194115-29062007">That could even be on ATLAS for easy
connection to backplane signals for e.g. voltage monitoring, Power Good
signal etc.?</span></span></font></div>
<div><font face="Arial" size="2"><span class="453194115-29062007"><span
class="453194115-29062007"></span></span></font> </div>
<div><font face="Arial" size="2"><span class="453194115-29062007"><span
class="453194115-29062007">So I think the answer for me in general
would be "YES!!"</span></span></font></div>
<div><font face="Arial" size="2"><span class="453194115-29062007"><span
class="453194115-29062007"></span></span></font> </div>
<div><font face="Arial" size="2"><span class="453194115-29062007"><span
class="453194115-29062007"></span></span></font> </div>
<div><font face="Arial" size="2"><span class="453194115-29062007"><span
class="453194115-29062007">73's,</span></span></font></div>
<div><font face="Arial" size="2"><span class="453194115-29062007"><span
class="453194115-29062007"></span></span></font> </div>
<div><font face="Arial" size="2"><span class="453194115-29062007"><span
class="453194115-29062007">Henry.</span></span></font></div>
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<pre class="moz-signature" cols="72">--
Ing. Jeroen Bastemeijer
Delft University of Technology
Department of Electrical Engineering
Electronic Instrumentation Laboratory
Mekelweg 4, Room 13.090
2628 CD Delft
The Netherlands
Phone: +31.15.27.86542
Fax: +31.15.27.85755
E-mail: <a class="moz-txt-link-abbreviated" href="mailto:J.Bastemeijer@TUDelft.nl">J.Bastemeijer@TUDelft.nl</a>
GPS: Lat N52.00002 Lon E4.37157 Alt 46.2m</pre>
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