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<DIV><FONT color=#000000 size=2>Hello!</FONT></DIV>
<DIV><FONT color=#000000 size=2></FONT> </DIV>
<DIV><FONT size=2>After two nights of bugging with this rounded top of the
triangle waveform I solved the problem! Yes way!</FONT></DIV>
<DIV><FONT size=2>Finally diodes got the boot, because of their knee. Away with
them. New design uses two opamps (they are cheap anyway) and a transistor
(ordinary NPN) and a bunch of resistors. The schematic is available
at:</FONT> </DIV>
<DIV><FONT size=2><A
href="http://imola.uni-mb.si/~bozicko/saw2tri_v2.gif">http://imola.uni-mb.si/~bozicko/saw2tri_v2.gif</A></FONT></DIV>
<DIV><FONT size=2></FONT><FONT color=#000000 size=2>I am very proud on this
converter since both peaks of triangle are razor sharp (as it should be in
theory). The only thing to watch out is, that you use high slew rate/bandwidth
opamps (TL082 roughly does it), otherwise there could be some spikes, when
sawtooth changes from higher to lower peak. It think Burr-Brown's OPA604 would
be ideal, since its is low cost and has 25V/us slew rate and 20 MHz of
bandwidth. You can remove spikes, if you use low amplitude sawtooth (lower than
the slew rate). The triangle remains perfect... I am impressed!</FONT></DIV>
<DIV> </DIV>
<DIV><FONT color=#000000 size=2>The old schematic is available at</FONT></DIV>
<DIV>
<DIV><FONT size=2><A
href="http://imola.uni-mb.si/~bozicko/saw2tri_v2.gif">http://imola.uni-mb.si/~bozicko/saw2tri.gif</A></FONT></DIV></DIV>
<DIV> </DIV>
<DIV><FONT color=#000000 size=2>Tadej Bozicko<BR>E-Mail : <A
href="mailto:tadej.bozicko@uni-mb.si">tadej.bozicko@uni-mb.si</A><BR>WWW :
<A
href="http://imola.uni-mb.si/~bozicko">http://imola.uni-mb.si/~bozicko</A><BR>WWW2:
<A
href="http://www.uni-mb.si/~uelelt68b">http://www.uni-mb.si/~uelelt68b</A><BR></FONT> </DIV></BODY></HTML>