<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div><span></span></div><div><meta http-equiv="content-type" content="text/html; charset=utf-8"><div></div><div>Roman --</div><div><br></div><div> I do not understand why the series resistor would not work well. We must be calculating differently?</div><div><a href="http://ijfritz.byethost4.com/sy_cir7.htm">http://ijfritz.byethost4.com/sy_cir7.htm</a></div><div>Isn't the resistance PTAT plus a constant?</div><div><br></div><div>Ian</div><div><br></div><div><br>On Apr 5, 2019, at 3:23 AM, Roman Sowa <<a href="mailto:modular@go2.pl">modular@go2.pl</a>> wrote:<br><br></div><blockquote type="cite"><div><span>I have used PT1000 once, mostly because I could, and out of curiosity, and because it's the only tempco available in SMD with well defined TCR. Nice thing about it is precise tempco, 3850 every time, while typical cheap tempsos have +/-400ppm tolerance.</span><br><span></span><br><span>But whatever math I tried, could not find nice and clean way to make the overal circuit down to 3300ppm from those 3850 in reasonable temp range. You can trim to whatever TCR by adding resistor, but it works only at given temperature. I guess it's still better than random TCR of regular cheap 3300ppm PTC in a small range of temperatures.</span><br><span></span><br><span>Roman</span><br><span></span><br><span>W dniu 2019-04-04 o 21:55, Mike Beauchamp pisze:</span><br><blockquote type="cite"><span>Has anyone used the Platinum RTD mentioned in the PDF? I see Digikey has quite a few in stock of different values, ±3850ppm/°C.</span><br></blockquote><blockquote type="cite"><span>Mike</span><br></blockquote><blockquote type="cite"><span>On 3/27/19 1:31 AM, Michael E Caloroso wrote:</span><br></blockquote><blockquote type="cite"><blockquote type="cite"><span>I wish he wasn't anonymous. He does very good work.</span><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><span></span><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><span>MC</span><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><span></span><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><span>On 3/27/19, Ian Fritz <<a href="mailto:ijfritz@comcast.net">ijfritz@comcast.net</a>> wrote:</span><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><span>“Guest” has been reporting his results regularly over at Muff’s for the past</span><br></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><span>few years. Very careful and thorough work, IMO.</span><br></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><span></span><br></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><span>Ian</span><br></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><span></span><br></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><span>On Mar 26, 2019, at 10:17 PM, Michael E Caloroso</span><br></blockquote></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><span><<a href="mailto:mec.forumreader@gmail.com">mec.forumreader@gmail.com</a>> wrote:</span><br></blockquote></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><span></span><br></blockquote></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><span>Not sure this was already posted, but this is an excellent article</span><br></blockquote></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><span>(technical descriptions including the math) on temperature</span><br></blockquote></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><span>compensation techniques used in exponential converters for VCO.</span><br></blockquote></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><span></span><br></blockquote></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><span><a href="http://www.openmusiclabs.com/2015/03/temperature-compensation-of-analog-exponential-converters/trackback/index.html">http://www.openmusiclabs.com/2015/03/temperature-compensation-of-analog-exponential-converters/trackback/index.html</a> </span><br></blockquote></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><span></span><br></blockquote></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><span>MC</span><br></blockquote></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><span>_______________________________________________</span><br></blockquote></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><span>Synth-diy mailing list</span><br></blockquote></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><span><a href="mailto:Synth-diy@synth-diy.org">Synth-diy@synth-diy.org</a></span><br></blockquote></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><span><a href="http://synth-diy.org/mailman/listinfo/synth-diy">http://synth-diy.org/mailman/listinfo/synth-diy</a></span><br></blockquote></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><span></span><br></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><span></span><br></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><span></span><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><span>_______________________________________________</span><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><span>Synth-diy mailing list</span><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><span><a href="mailto:Synth-diy@synth-diy.org">Synth-diy@synth-diy.org</a></span><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><span><a href="http://synth-diy.org/mailman/listinfo/synth-diy">http://synth-diy.org/mailman/listinfo/synth-diy</a></span><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><span></span><br></blockquote></blockquote><blockquote type="cite"><span>_______________________________________________</span><br></blockquote><blockquote type="cite"><span>Synth-diy mailing list</span><br></blockquote><blockquote type="cite"><span><a href="mailto:Synth-diy@synth-diy.org">Synth-diy@synth-diy.org</a></span><br></blockquote><blockquote type="cite"><span><a href="http://synth-diy.org/mailman/listinfo/synth-diy">http://synth-diy.org/mailman/listinfo/synth-diy</a></span><br></blockquote><span>_______________________________________________</span><br><span>Synth-diy mailing list</span><br><span><a href="mailto:Synth-diy@synth-diy.org">Synth-diy@synth-diy.org</a></span><br><span><a href="http://synth-diy.org/mailman/listinfo/synth-diy">http://synth-diy.org/mailman/listinfo/synth-diy</a></span><br></div></blockquote></div></body></html>