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Tak uz vieme ako to dopadlo po spajkovani. Hodnota vsetkych sa
mierne posunula, vid tabulka dole. Rezistory su tieto <a
class="moz-txt-link-freetext"
href="https://foilresistors.com/docs/63209/frsm.pdf"
moz-do-not-send="true">https://foilresistors.com/docs/63209/frsm.pdf</a>
radovo to sedi s obrazkom 6.
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<div class="moz-cite-prefix"><br>
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<div class="moz-cite-prefix">Ale zistil som, ze mame na hovno pec.
Treba to pretavovat v parach, nie infracervenou. Po prvom merani
bola na kazdom kuse obrovska chyba (10.001xxx namiesto
10.000xxx). Bolo to divne, preto som zobral tri nezaspajkovane
kusy a nechal ich prejst teplotnym cyklom v peci bez
spajkovania. Hodnoty sa zmenili len malo:<br>
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<div class="moz-cite-prefix">Hodnota z pasky Hodnota po tepelnom
cykle (kOhm)<br>
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<div class="moz-cite-prefix">10.000128 10.000017<br>
10.000761 10.000552<br>
10.000635 10.000468<br>
<br>
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<div class="moz-cite-prefix">Tak som rucne pretavil vsetky
rezistory, to je presne co by sa nemalo robit koli mechanickemu
napatiu. A hodnoty sa zrovnali na podobnu uroven ako tie tri
kusy, ktore presli len teplotnym cyklom. <br>
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<div class="moz-cite-prefix"><br>
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<div class="moz-cite-prefix">Takze vysledok optimalizacie je
nasledovny. Snaha dobra, ale tym ze 4 kusy usli velmi jemne inak
tak koniec tabulky je skaredy. Na univerzitu dobre, ale na
seriozne ppm treba lepsie vysledky. Som zvedavy ako ujdu 100k
rezistory, ktore maju este tensiu kovovu foliu a ako ujdu 20
Ohmove, ktore su vyrobene s velmi hrubej. Ocakavam velky
rozdiel. <br>
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<table width="905" cellspacing="0" cellpadding="0" border="0">
<colgroup><col
style="mso-width-source:userset;mso-width-alt:3291;width:68pt"
width="90"> <col
style="mso-width-source:userset;mso-width-alt:3035;width:62pt"
width="83"> <col
style="mso-width-source:userset;mso-width-alt:4864;
width:100pt" width="133" span="2"> <col
style="mso-width-source:userset;mso-width-alt:4900;width:101pt"
width="134"> <col
style="mso-width-source:userset;mso-width-alt:4022;width:83pt"
width="110"> <col
style="mso-width-source:userset;mso-width-alt:3766;width:77pt"
width="103"> <col
style="mso-width-source:userset;mso-width-alt:4352;width:89pt"
width="119"> </colgroup><tbody>
<tr style="height:63.0pt" height="84">
<td class="xl76" style="height:63.0pt;width:68pt"
width="90" height="84" align="center"><b><br>
</b></td>
<td class="xl76" style="width:62pt" width="83"
align="center"><b>Rezistor cislo</b></td>
<td class="xl76" style="width:100pt" width="133"
align="center"><b>Hodnoty kOhm pred spajkovanim</b></td>
<td class="xl76" style="width:100pt" width="133"
align="center"><b>Hodnoty kOhm po spajkovani</b></td>
<td class="xl76" style="width:101pt" width="134"
align="center"><b>Deliaci pomer pred spajkovanim</b></td>
<td class="xl76" style="width:83pt" width="110"
align="center"><b>Chyba pomeru pred spajkovanim ppm</b></td>
<td class="xl76" style="width:77pt" width="103"
align="center"><b>Deliaci pomer po spajkovani</b></td>
<td class="xl76" style="width:89pt" width="119"
align="center"><b>Chyba pomeru po spajkovani ppm</b></td>
</tr>
<tr style="height:15.0pt" height="20">
<td class="xl69" style="height:15.0pt" height="20"
align="center">R1</td>
<td class="xl73" align="center">1</td>
<td class="xl74" align="center">10.000362</td>
<td class="xl74" align="center">10.000254</td>
<td class="xl69" align="center">1</td>
<td class="xl71" align="center">0.00</td>
<td class="xl69" align="center">1</td>
<td class="xl71" align="center">0.00</td>
</tr>
<tr style="height:15.0pt" height="20">
<td class="xl69" style="height:15.0pt" height="20"
align="center">R2</td>
<td class="xl73" align="center">12</td>
<td class="xl74" align="center">10.000749</td>
<td class="xl74" align="center">10.000497</td>
<td class="xl69" align="center">0.916668242</td>
<td class="xl71" align="center">1.72</td>
<td class="xl69" align="center">0.91666725</td>
<td class="xl71" align="center">0.64</td>
</tr>
<tr style="height:15.0pt" height="20">
<td class="xl69" style="height:15.0pt" height="20"
align="center">R3</td>
<td class="xl73" align="center">6</td>
<td class="xl74" align="center">10.000424</td>
<td class="xl74" align="center">10.000146</td>
<td class="xl69" align="center">0.833333258</td>
<td class="xl71" align="center">-0.09</td>
<td class="xl69" align="center">0.83333248</td>
<td class="xl71" align="center">-1.02</td>
</tr>
<tr style="height:15.0pt" height="20">
<td class="xl69" style="height:15.0pt" height="20"
align="center">R4</td>
<td class="xl73" align="center">14</td>
<td class="xl74" align="center">10.000715</td>
<td class="xl74" align="center">10.000341</td>
<td class="xl69" align="center">0.750000983</td>
<td class="xl71" align="center">1.31</td>
<td class="xl69" align="center">0.75000063</td>
<td class="xl71" align="center">0.84</td>
</tr>
<tr style="height:15.0pt" height="20">
<td class="xl69" style="height:15.0pt" height="20"
align="center">R5</td>
<td class="xl73" align="center">4</td>
<td class="xl74" align="center">10.000433</td>
<td class="xl74" align="center">10.000101</td>
<td class="xl69" align="center">0.666666283</td>
<td class="xl71" align="center">-0.57</td>
<td class="xl69" align="center">0.66666716</td>
<td class="xl71" align="center">0.74</td>
</tr>
<tr style="height:15.0pt" height="20">
<td class="xl69" style="height:15.0pt" height="20"
align="center">R6</td>
<td class="xl73" align="center">3</td>
<td class="xl74" align="center">10.000660</td>
<td class="xl74" align="center">10.000235</td>
<td class="xl69" align="center">0.583333933</td>
<td class="xl71" align="center">1.03</td>
<td class="xl69" align="center">0.58333569</td>
<td class="xl71" align="center">4.03</td>
</tr>
<tr style="height:15.0pt" height="20">
<td class="xl69" style="height:15.0pt" height="20"
align="center">R7</td>
<td class="xl73" align="center">5</td>
<td class="xl74" align="center">10.000451</td>
<td class="xl74" align="center">9.999981</td>
<td class="xl69" align="center">0.499999692</td>
<td class="xl71" align="center">-0.62</td>
<td class="xl69" align="center">0.5000031</td>
<td class="xl71" align="center">6.19</td>
</tr>
<tr style="height:15.0pt" height="20">
<td class="xl69" style="height:15.0pt" height="20"
align="center">R8</td>
<td class="xl73" align="center">11</td>
<td class="xl74" align="center">10.000630</td>
<td class="xl74" align="center">10.000212</td>
<td class="xl69" align="center">0.416667192</td>
<td class="xl71" align="center">1.26</td>
<td class="xl69" align="center">0.41667262</td>
<td class="xl71" align="center">14.29</td>
</tr>
<tr style="height:15.0pt" height="20">
<td class="xl69" style="height:15.0pt" height="20"
align="center">R9</td>
<td class="xl73" align="center">10</td>
<td class="xl74" align="center">10.000473</td>
<td class="xl74" align="center">10.000548</td>
<td class="xl69" align="center">0.3333332</td>
<td class="xl71" align="center">-0.40</td>
<td class="xl69" align="center">0.33334022</td>
<td class="xl71" align="center">20.67</td>
</tr>
<tr style="height:15.0pt" height="20">
<td class="xl69" style="height:15.0pt" height="20"
align="center">R10</td>
<td class="xl73" align="center">2</td>
<td class="xl74" align="center">10.000620</td>
<td class="xl74" align="center">10.000751</td>
<td class="xl69" align="center">0.250000517</td>
<td class="xl71" align="center">2.07</td>
<td class="xl69" align="center">0.25000503</td>
<td class="xl71" align="center">20.11</td>
</tr>
<tr style="height:15.0pt" height="20">
<td class="xl69" style="height:15.0pt" height="20"
align="center">R11</td>
<td class="xl73" align="center">15</td>
<td class="xl74" align="center">10.000503</td>
<td class="xl74" align="center">10.000533</td>
<td class="xl69" align="center">0.166666608</td>
<td class="xl71" align="center">-0.35</td>
<td class="xl69" align="center">0.16666814</td>
<td class="xl71" align="center">8.82</td>
</tr>
<tr style="height:15.0pt" height="20">
<td class="xl69" style="height:15.0pt" height="20"
align="center">R12</td>
<td class="xl73" align="center">7</td>
<td class="xl74" align="center">10.000592</td>
<td class="xl74" align="center">10.000292</td>
<td class="xl69" align="center">0.083333675</td>
<td class="xl71" align="center">4.10</td>
<td class="xl69" align="center">0.08333306</td>
<td class="xl71" align="center">-3.22</td>
</tr>
<tr style="height:15.0pt" height="20">
<td class="xl68" style="height:15.0pt" height="20"
align="center"><br>
</td>
<td class="xl67" align="center"><br>
</td>
<td class="xl67" align="center"><br>
</td>
<td class="xl67" align="center"><br>
</td>
<td class="xl65" align="center"><br>
</td>
<td class="xl72" align="center"><br>
</td>
<td class="xl65" align="center"><br>
</td>
<td class="xl65" align="center"><br>
</td>
</tr>
<tr style="height:15.0pt" height="20">
<td class="xl68" style="height:15.0pt" height="20"
align="center"><br>
</td>
<td class="xl65" align="center"><br>
</td>
<td class="xl65" align="center"><br>
</td>
<td class="xl65" align="center"><br>
</td>
<td class="xl65" align="center">suma chyby</td>
<td class="xl75" align="center">13.52 ppm<br>
</td>
<td class="xl66" align="center"><br>
</td>
<td class="xl75" align="center">80.59 ppm<br>
</td>
</tr>
</tbody>
</table>
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<div class="moz-cite-prefix"><br>
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<div class="moz-cite-prefix">On 15/11/2023 10:42, Jan Waclawek
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:PC1952023111510422404163b5ba0f8@wekPC">
<pre class="moz-quote-pre" wrap="">Oznacme R0 aritmeticky priemer odporov. Predpokladajme, ze ich odpory su
rozlozene rovnomerne, t.j. je jeden par R0*(1+-d), jeden par R0*(1+-2d),
atd. az po R0*(1+-6d) (d je v % alebo ppm alebo co len chces; a ano,
presnejsie by to malo byt R0*(1+-1/2d), R0*(1+-3/2d) atd. ale ide o
princip a ten je rovnaky).
Delic ma celkovy odpor 12*R0 a spodna strana ma odpor ktory je suctom N
odporov, t.j. R0*(N + d1 + d2 + ... + dN), kde d1 atd. su relativne chyby
jednotlivych odporov, t.j. kazdy z nich moze byt nejaky kladny alebo
zaporny celociselny nasobok d. Vystupne napatie Nteho vystupu je V0*(N +
d1 + d2 + ... + dN)/12, idealne by bolo V0*N/12, cize absolutna chyba
vystupneho napatia je rozdiel tychto dvoch cize V0*(d1 + d2 + ... + dN)/12.
Teraz je otazne, co chces dosiahnut. Povodne si pisal nieco o monotonnosti;
ten delic bude monotonny, takze si mozno myslel monotonnost prebehu chyby
od N, ale kedze jednotlive chyby su kladne aj zaporne, monotonne to nemoze
byt. Mozno si predstavujes nejaky velky skok na zaciatku a potom
monotonne, ale ani to sa neda dosiahnut. Da sa dosiahnut monotonny priebeh
v jednej polovici a potom opacny monotonny v druhej (nieco ako dva kusy
paraboly v strede spojene), ale to asi nechces.
Asi chces aby najvacsia chyba zo vsetkych bola co najmensia, t.j. aby sa
dala "krivka" (lomena ciara) chyby obmedzit zhora aj zdola co najviac. K
tomu prirodzene vedie to striedanie kladnych a zapornych chyb. Medzi
susednymi hodnotami najvacsi rozdiel je +-6d, takze chces, aby ten rozdiel
bol symetricky rozdeleny okolo nuly, takze ten optimalny vyber je nejaky
takyto:
N odpor vystupna chyba (t.j. suma chyb 1..N) * 12
1 R0+3d +3d
2 R0-6d -3d
3 R0+6d +3d
4 R0-5d -2d
5 R0+5d +3d
6 R0-4d -1d
7 R0+4d +3d
8 R0-3d 0
9 R0-2d -2d
10 R0+2d 0
11 R0-1d -1d
12 R0+1d 0
Samozrejme moznosi je vela, pointa je, odchylku vystupu menej ako +-3d/12
nedosiahnes takze to je pri takejto definicii ulohy optimalne riesenie.
Tu je napriklad taka "symetricka" verzia:
odpor suma
+3 +3
-6 -3
+5 +2
-4 -2
+2 0
-1 -1
+1 0
-2 -2
+4 +2
-5 -3
+6 +3
-3 0
Ale mohol by si napriklad chciet aj najmensiu relativnu chybu vystupneho
napatia (t.j. (d1+d2+...+dN) / N ), co je uplne ina uloha a nechce sa mi
nad nou rozmyslat.
wek
<span style="white-space: normal">
</span></pre>
</blockquote>
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