{"id":800,"date":"2012-06-12T16:30:00","date_gmt":"2012-06-12T15:30:00","guid":{"rendered":"http:\/\/www.marallo.sk\/?p=800"},"modified":"2012-06-12T16:31:50","modified_gmt":"2012-06-12T15:31:50","slug":"vypocet-predradnika-k-voltmetru","status":"publish","type":"post","link":"https:\/\/www.marallo.sk\/?p=800","title":{"rendered":"V\u00fdpo\u010det predradn\u00edka k voltmetru…"},"content":{"rendered":"

V minulom \u010dl\u00e1nku<\/a> sme si urobili amp\u00e9rmeter, ale ve\u010f ja chcem aby mi zdroj ukazoval aj nap\u00e4tie. Po\u010fme si teda vyr\u00e1ta\u0165 predradn\u00edk k voltmetru…<\/p>\n

Z\u00e1kladn\u00fd vzorec je:
\nRp = \u00a0 \u00a0 Up\u00a0\u00a0\u00a0\u00a0<\/span><\/span>
\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Iv<\/span><\/p>\n

Rp \u2013 odpor predradn\u00edka (sna\u017e\u00edme sa vypo\u010d\u00edta\u0165)<\/span>
\n Up \u2013 nap\u00e4tie na predradn\u00edku pri plnom vych\u00fdlen\u00ed ru\u010di\u010dky<\/span>
\n Iv \u2013 pr\u00fad te\u010d\u00faci meradlom pri plnej v\u00fdchylke (je nap\u00edsan\u00e9 na panelovom meradle)<\/span><\/p>\n

Ako vypo\u010d\u00edtame Up? Tak \u017ee odpo\u010d\u00edtame Uv od maxim\u00e1lneho nap\u00e4tia ktor\u00e9 chceme mera\u0165.<\/p>\n

Up = U \u2013 Uv<\/span><\/p>\n

Uv = Iv x Rv<\/span><\/p>\n

Up \u2013 nap\u00e4tie na predradn\u00edku pri plnom vych\u00fdlen\u00ed ru\u010di\u010dky<\/span>
\nU \u2013 maxim\u00e1lne meran\u00e9 nap\u00e4tie<\/span>
\n Uv – nap\u00e4tie na meradle pri plnom vych\u00fdlen\u00ed ru\u010di\u010dky<\/span>
\n Iv – pr\u00fad te\u010d\u00faci meradlom pri plnej v\u00fdchylke (je nap\u00edsan\u00e9 na panelovom meradle)<\/span>
\n Rv \u2013 vn\u00fatorn\u00fd odpor meradla (zmeriame ohmmetrom)<\/span><\/p>\n

Pr\u00edklad:
\nNa burze v Borovciach sme k\u00fapili panelov\u00e9 meradlo, na ktorom je nap\u00edsan\u00fd pr\u00fad 1mA. Ohmmetrom sme zmerali jeho vn\u00fatorn\u00fd odpor 192Ohmov. No a chceme ho da\u0165 do zdroja s maxim\u00e1lnym nap\u00e4t\u00edm 20Voltov. Po\u010fme po\u010d\u00edta\u0165:<\/p>\n

Najprv si spo\u010d\u00edtame nap\u00e4tie potrebn\u00e9 na pln\u00e9 vych\u00fdlenie ru\u010di\u010dky:<\/p>\n

Uv = Iv x Rv = 0,001 x 192 = 0,192V<\/span><\/p>\n

Up = U \u2013 Uv = 20 \u2013 0,192 = 19,808V<\/span><\/p>\n

M\u00e1me nap\u00e4tie ktor\u00e9 je na predradn\u00edku pri plnej v\u00fdchylke, po\u010fme vyr\u00e1ta\u0165 ten odpor.<\/p>\n

Rp =\u00a0\u00a0\u00a0 Up \u00a0\u00a0<\/span> =\u00a0\u00a0\u00a0 19,808 \u00a0\u00a0<\/span>\u00a0 = 19808 Ohm<\/span>
\n \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Iv \u00a0\u00a0 \u00a0 \u00a0\u00a0\u00a0\u00a0 0,001<\/span><\/p>\n

Na predradn\u00edk teda potrebujeme odpor 19,8k. Tak\u00fd nem\u00e1me, a tak zapoj\u00edme do s\u00e9rie 10k a 9k8…<\/p>\n","protected":false},"excerpt":{"rendered":"