{"id":17517,"date":"2023-07-31T16:02:26","date_gmt":"2023-07-31T15:02:26","guid":{"rendered":"http:\/\/www.crowave.com\/blog\/?p=17517"},"modified":"2023-07-31T16:02:26","modified_gmt":"2023-07-31T15:02:26","slug":"brojilo-iskra-f122-e3","status":"publish","type":"post","link":"https:\/\/www.crowave.com\/blog\/2023\/07\/31\/brojilo-iskra-f122-e3\/","title":{"rendered":"Jednofazno brojilo Iskra F-122 \/ E3"},"content":{"rendered":"<p>Danas je nabavljeno jednofazno indukcijsko izmjeni\u010dno brojilo potro\u0161nje djelatne energije oznake F-122\/E3, slovenskog proizvo\u0111a\u010da Iskra iz 1960. godine. Tvrtka Iskra vu\u010de korijene iz 1946. godine te je i danas prisutna na tr\u017ei\u0161tu. Kroz \u010ditavo razdoblje postojanja nudi \u0161irok spektar proizvoda iz podru\u010dja elektronike, elektrotehnike, telekomunikacija, energetike, automatizacije i tome srodnih proizvodnih grana.<\/p>\n<p>&nbsp;<\/p>\n<p><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_01.jpg\" rel=\"lightbox[17517]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-17518\" src=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_01.jpg\" alt=\"\" width=\"1000\" height=\"1340\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_01.jpg 1000w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_01-768x1029.jpg 768w\" sizes=\"auto, (max-width: 1000px) 100vw, 1000px\" \/><\/a><\/p>\n<p><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_02.jpg\" rel=\"lightbox[17517]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-17519\" src=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_02.jpg\" alt=\"\" width=\"1300\" height=\"498\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_02.jpg 1300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_02-768x294.jpg 768w\" sizes=\"auto, (max-width: 1300px) 100vw, 1300px\" \/><\/a><\/p>\n<p style=\"text-align: center;\"><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_03.jpg\" rel=\"lightbox[17517]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-17520\" src=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_03.jpg\" alt=\"\" width=\"1300\" height=\"465\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_03.jpg 1300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_03-768x275.jpg 768w\" sizes=\"auto, (max-width: 1300px) 100vw, 1300px\" \/><\/a><span style=\"color: #00ffff;\"><em>Na olovnim plombama je otisnut tada\u0161nji naziv dr\u017eave FNRJ (1945-1963) i godina pe\u010da\u0107enja (stavljanja u pogon) 1961.<\/em><\/span><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_04.jpg\" rel=\"lightbox[17517]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-17521\" src=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_04.jpg\" alt=\"\" width=\"1300\" height=\"666\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_04.jpg 1300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_04-768x393.jpg 768w\" sizes=\"auto, (max-width: 1300px) 100vw, 1300px\" \/><\/a><\/p>\n<p style=\"text-align: center;\"><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_05.jpg\" rel=\"lightbox[17517]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-17522\" src=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_05.jpg\" alt=\"\" width=\"600\" height=\"499\" \/><\/a><em><span style=\"color: #00ffff;\">Strujni elektromagnet spaja se u seriju na fazni vodi\u010d, a naponski elektromagnet se spaja paralelno na fazni i nulti vodi\u010d. Izvodi oba elektromagneta su zasebno dostupni na priklju\u010dnim stezaljkama, tako da se zajedni\u010dki spoj strujnog i naponskog elektromagneta na fazni vodi\u010d obi\u010dno ostvaruje preko kratkospojnog mosti\u0107a.<\/span><\/em><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>Op\u0107enito o konstrukciji i na\u010dinu rada jednofaznih indukcijskih brojila pisali smo u objavi <a href=\"http:\/\/www.crowave.com\/blog\/2023\/07\/30\/siemens-schuckert-werke-w9\/\" target=\"_blank\" rel=\"noopener noreferrer\">Kilovatsatno brojilo izmjeni\u010dne struje Siemens Schuckert Werke W9<\/a> pa ovdje ne\u0107emo ponavljati \u010ditav tekst. Prisjetiti \u0107emo se samo koje komponente moramo potra\u017eiti unutar jednog takvog brojila:<\/p>\n<ul>\n<li>strujni elektromagnet<\/li>\n<li>naponski elektromagnet<\/li>\n<li>rotiraju\u0107i aluminijski disk na finim le\u017eajevima spregnut sa broj\u010danikom<\/li>\n<li>sistem za kompenzaciju (pode\u0161avanje) faznog pomaka unutra\u0161njeg pogonskog sistema (90\u00b0)<\/li>\n<li>sistem za zaustavljanje vrtnje kada nema potro\u0161nje struje<\/li>\n<li>sistem za pokretanje vrtnje ve\u0107 kod vrlo male potro\u0161nje struje (kompenzacija trenja rotiraju\u0107eg diska i momenta potrebnog za pokretanje broj\u010danika)<\/li>\n<li>permanentni magnet za regulaciju brzine vrtnje rotiraju\u0107eg diska (moment ko\u010denja\/usporenja vrtnje diska)<\/li>\n<li>priklju\u010dne spojnice<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_06.jpg\" rel=\"lightbox[17517]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-17523\" src=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_06.jpg\" alt=\"\" width=\"1000\" height=\"1234\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_06.jpg 1000w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_06-768x948.jpg 768w\" sizes=\"auto, (max-width: 1000px) 100vw, 1000px\" \/><\/a><\/p>\n<p style=\"text-align: center;\"><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_07.jpg\" rel=\"lightbox[17517]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-17524\" src=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_07.jpg\" alt=\"\" width=\"1300\" height=\"977\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_07.jpg 1300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_07-768x577.jpg 768w\" sizes=\"auto, (max-width: 1300px) 100vw, 1300px\" \/><\/a><span style=\"color: #00ffff;\"><em>Nasuprotno postavljeni naponski i strujni elektromagneti sa rotiraju\u0107im aluminijskim diskom izme\u0111u njih.<\/em><\/span><\/p>\n<p>Naponski i strujni elektromagneti imaju specifi\u010dne izvedbe namotaja i \u017eeljeznih jezgri kako bi se izme\u0111u istih stvorio fazni pomak \u0161to bli\u017ei 90\u00b0. Jezgra elektromagneta, kao \u0161to vidimo na slikama, ne prolazi samo sredi\u0161tem zavojnice, nego se zatvara i oko nje. Taj okolni okvir jezgre predstavlja svojevrsni magnetski kratki spoj preko kojeg se zatvara veliki dio magnetskog toka, te on ne prolazi kroz rotiraju\u0107i disk i ne utje\u010de na zakretni moment. Ovakvom raspodjelom magnetskog toka na dio koji prolazi kroz disk i dio koji se kratko spaja, namje\u0161ta se potrebni fazni kut pogonskog sistema.<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_08.jpg\" rel=\"lightbox[17517]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-17525\" src=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_08.jpg\" alt=\"\" width=\"1300\" height=\"556\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_08.jpg 1300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_08-768x328.jpg 768w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_08-1170x500.jpg 1170w\" sizes=\"auto, (max-width: 1300px) 100vw, 1300px\" \/><\/a><\/p>\n<p><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_09.jpg\" rel=\"lightbox[17517]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-17526\" src=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_09.jpg\" alt=\"\" width=\"1300\" height=\"654\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_09.jpg 1300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_09-768x386.jpg 768w\" sizes=\"auto, (max-width: 1300px) 100vw, 1300px\" \/><\/a><\/p>\n<p><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_10.jpg\" rel=\"lightbox[17517]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-17527\" src=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_10.jpg\" alt=\"\" width=\"1300\" height=\"632\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_10.jpg 1300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_10-768x373.jpg 768w\" sizes=\"auto, (max-width: 1300px) 100vw, 1300px\" \/><\/a><\/p>\n<hr \/>\n<p>&nbsp;<\/p>\n<p style=\"text-align: center;\"><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_11.jpg\" rel=\"lightbox[17517]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-17528\" src=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_11.jpg\" alt=\"\" width=\"1300\" height=\"711\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_11.jpg 1300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_11-768x420.jpg 768w\" sizes=\"auto, (max-width: 1300px) 100vw, 1300px\" \/><\/a><span style=\"color: #00ffff;\"><em>Broj\u010danik potro\u0161nje elektri\u010dne energije (kWh) spregnut sa rotiraju\u0107im aluminijskim diskom.<\/em><\/span><\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: center;\"><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_12.jpg\" rel=\"lightbox[17517]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-17529\" src=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_12.jpg\" alt=\"\" width=\"1300\" height=\"505\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_12.jpg 1300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_12-768x298.jpg 768w\" sizes=\"auto, (max-width: 1300px) 100vw, 1300px\" \/><\/a><em><span style=\"color: #00ffff;\">Prijenos zakretnog momenta sa aluminijskog diska preko sistema zup\u010danika na mehani\u010dki broj\u010danik.<\/span><\/em><\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: center;\"><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_13.jpg\" rel=\"lightbox[17517]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-17530\" src=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_13.jpg\" alt=\"\" width=\"1300\" height=\"517\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_13.jpg 1300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_13-768x305.jpg 768w\" sizes=\"auto, (max-width: 1300px) 100vw, 1300px\" \/><\/a><span style=\"color: #00ffff;\"><em>Sistem za zaustavljanje vrtnje kada nema potro\u0161nje struje.<br \/>\n<\/em><\/span><\/p>\n<p>Sistem za zaustavljanje vrtnje kada nema potro\u0161nje struje. Jedna metalna zastavica je trajno pri\u010dvr\u0161\u0107ena na elektromagnet naponskog svitka koji je stalno pod konstantnim naponom. Druga zastavica je pri\u010dvr\u0161\u0107ena na osovinu rotiraju\u0107eg diska. Me\u0111usobno magnetsko provla\u010denje ove dvije zastavice je dovoljno jako da zaustavi slabu vrtnju diska. Ovdje tako\u0111er primje\u0107ujemo svojevrsni zvjezdasti aluminijski element oko osovine diska. Vidimo da je jedan krak odignut od povr\u0161ine diska i to ba\u0161 na mjestu gdje se na osovini nalazi zastavica. Ovime je vjerojatno izvr\u0161ena kompenzacija ko\u010denja koju prouzrokuje svako pribli\u017eavanje zastavica tijekom normalne vrtnje diska ili pak kompenzacija balansa zbog ekscentri\u010dnog elementa zastavice postavljene na osovinu.<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: center;\"><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_14.jpg\" rel=\"lightbox[17517]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-17531\" src=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_14.jpg\" alt=\"\" width=\"1300\" height=\"700\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_14.jpg 1300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_14-768x414.jpg 768w\" sizes=\"auto, (max-width: 1300px) 100vw, 1300px\" \/><\/a><span style=\"color: #00ffff;\"><em>Fina regulacija unutra\u0161njeg faznog pomaka pogonskog sistema na to\u010dno 90\u00b0 pomo\u0107u aluminijskih kratkospojnika i kratko spojene zavojnice sa mogu\u0107nosti regulacije duljine.<\/em> <\/span><\/p>\n<p>Fina regulacija unutra\u0161njeg faznog pomaka pogonskog sistema na to\u010dno 90\u00b0. Ve\u0107 smo rekli da se pribli\u017ena regulacija faznog pomaka izme\u0111u strujnog i naponskog elektromagneta posti\u017ee samom konstrukcijom namotaja i jezgri, odnosno raspodjelom toka magnetskih rasipanja mijenja se smjer i veli\u010dina vektora korisnog naponskog magnetskog toka. Dodatna fina regulacija ovdje se posti\u017ee na strujnom elektromagnetu i kratko spojenim aluminijskim prstenima i kratko spojenom zavojnicom od nekoliko namotaja kojoj se mo\u017ee regulirati ukupna duljina. Ovime se vi\u0161e ili manje optere\u0107uje strujni magnet \u010dime se mijenja i vektor strujnog toka. Time se pomo\u0107u ova dva sistema namje\u0161ta pomak naponskog i strujnog vektora za to\u010dno 90\u00b0.<\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: center;\"><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_15.jpg\" rel=\"lightbox[17517]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-17532\" src=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_15.jpg\" alt=\"\" width=\"1300\" height=\"441\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_15.jpg 1300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_15-768x261.jpg 768w\" sizes=\"auto, (max-width: 1300px) 100vw, 1300px\" \/><\/a><em><span style=\"color: #00ffff;\">Sistem za pokretanje vrtnje ve\u0107 kod vrlo male potro\u0161nje struje, odnosno kompenzaciju trenja rotiraju\u0107eg diska i momenta potrebnog za pokretanje broj\u010danika. Na slici lijevo se vidi vanjski vijak osovine za pode\u0161avanje (pored otisnutog slova n), a na slici desno se vidi pokretni jezi\u010dak na drugom kraju osovine koji se nalazi blizu centralne osovine diska.<br \/>\n<\/span><\/em><\/p>\n<p>Sistem za kompenzaciju trenja rotiraju\u0107eg diska i momenta potrebnog za pokretanje broj\u010danika kod malih protoka struje (malih optere\u0107enja) sastoji se od malog metalnog jezi\u010dka spojenog na naponski svitak i preko kojeg se onda na disk dovodi pomo\u0107ni magnetski tok za stvaranje pomo\u0107nog (dodatnog) zakretnog momenta. Jezi\u010dak postavljen blizu diska se mo\u017ee zakretati preko sistema poluge \u010dime se mijenja njegov polo\u017eaj od centra rotacije diska, a time i ja\u010dina zakretnog momenta koji isti stvara.<\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: center;\"><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_16.jpg\" rel=\"lightbox[17517]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-17533\" src=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_16.jpg\" alt=\"\" width=\"1300\" height=\"428\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_16.jpg 1300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_16-768x253.jpg 768w\" sizes=\"auto, (max-width: 1300px) 100vw, 1300px\" \/><\/a><span style=\"color: #00ffff;\"><em>Permanentni magnet za regulaciju brzine vrtnje rotiraju\u0107eg diska. Posebnim mehanizmom sa vijcima zazor magneta se mo\u017ee vi\u0161e ili manje pribli\u017eiti centru diska. Time se mijenja brzina prolaza diska izme\u0111u zazora magneta, \u010dime se mijenja i ja\u010dina induciranih vrtlo\u017enih struja, a time se onda mijenja i stvoreni magnetski protumoment ko\u010denja.<\/em><\/span><\/p>\n<p>&nbsp;<\/p>\n<hr \/>\n<p>&nbsp;<\/p>\n<p>Na prethodno opisanom Siemensovom brojilu iz 1943. godine nazna\u010dena je maksimalna struja 10 A, dok je na ovom Iskrinom brojilu iz 1960. godine struja 10 (20) A. Ove oznake daju podatak o maksimalnoj mjernoj struji kod koje brojilo zadr\u017eava deklariranu to\u010dnost mjerenja.<\/p>\n<p>Jasno da se s razvojem elektrike i elektri\u010dnih ku\u0107anskih aparata kroz vrijeme sve vi\u0161e pove\u0107avala prosje\u010dna potro\u0161nja struje u doma\u0107instvima. U 1940-tim godinama ku\u0107na elektri\u010dna instalacija je uklju\u010divala nekoliko \u017earulja, te jednu ili dvije uti\u010dnice za eventualno neki elektri\u010dni ure\u0111aj, a sva ta tro\u0161ila zajedno nisu vukla vi\u0161e od 10 A struje. S vremenom, elektri\u010dnih aparata je bilo sve vi\u0161e, posebno onih s elektromotorima i grija\u010dima koji tro\u0161e vi\u0161e struje. Svi ti ure\u0111aji naravno nikad nisu uklju\u010deni istovremeno i prosje\u010dna potro\u0161nja struje je i dalje ispod 10 A, no sad se ve\u0107 mogu pojaviti i razdoblja ve\u0107e potro\u0161nje od 10 A kad se primjerice istovremeno uklju\u010de neki sna\u017eni elektri\u010dni ure\u0111aji.<\/p>\n<p>Time je nastala potreba za brojilima sa pro\u0161irenim strujnim opsegom. Na\u0161e brojilo Iskra F-122 \/ E3 je tako predvi\u0111eno za prosje\u010dnu potro\u0161nju struje do 10 A, no mo\u017ee se bez problema opteretiti i sa dvostruko ja\u010dom strujom (20 A), a da pogre\u0161ka mjerenja pri tome ne pre\u0111e dozvoljenu granicu i da se strujni svitak ne zagrijava izvan dozvoljenih granica. Neka bolja brojila mogla su se opteretiti i 3-4 puta ve\u0107om strujom od nominalne, no takvo brojilo je osim korekcije zakretnog momenta kod malih optere\u0107enja moralo biti opremljeno i sistemom korekcije okretanja diska kod velikih optere\u0107enja kako bi mjerenje na malim i velikim strujama bilo u granicama tolerancije. Krivulja to\u010dnosti se ina\u010de kod svih indukcijskih brojila stalno mijenja s optere\u0107enjem i to ne linearno, nego se izmjenjuje u pozitivne i negativne vrijednosti, no one obi\u010dno ne prelaze \u00b11 %.<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<div id=\"s3gt_translate_tooltip_mini\" class=\"s3gt_translate_tooltip_mini_box\" style=\"background: initial !important; border: initial !important; border-radius: initial !important; border-spacing: initial !important; border-collapse: initial !important; direction: ltr !important; flex-direction: initial !important; font-weight: initial !important; height: initial !important; letter-spacing: initial !important; min-width: initial !important; max-width: initial !important; min-height: initial !important; max-height: initial !important; margin: auto !important; outline: initial !important; padding: initial !important; position: absolute; table-layout: initial !important; text-align: initial !important; text-shadow: initial !important; width: initial !important; word-break: initial !important; word-spacing: initial !important; overflow-wrap: initial !important; box-sizing: initial !important; display: initial !important; color: inherit !important; font-size: 13px !important; font-family: X-LocaleSpecific, sans-serif, Tahoma, Helvetica !important; line-height: 13px !important; vertical-align: top !important; white-space: inherit !important; left: 5px; top: 8510px; opacity: 0.65;\">\n<div id=\"s3gt_translate_tooltip_mini_logo\" class=\"s3gt_translate_tooltip_mini\" title=\"Translate selected text\"><\/div>\n<div id=\"s3gt_translate_tooltip_mini_sound\" class=\"s3gt_translate_tooltip_mini\" title=\"Play\"><\/div>\n<div id=\"s3gt_translate_tooltip_mini_copy\" class=\"s3gt_translate_tooltip_mini\" title=\"Copy text to Clipboard\"><\/div>\n<style type=\"text\/css\" media=\"print\">#s3gt_translate_tooltip_mini { display: none !important; }<\/style>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Danas je nabavljeno jednofazno indukcijsko izmjeni\u010dno brojilo potro\u0161nje djelatne energije oznake F-122\/E3, slovenskog proizvo\u0111a\u010da Iskra iz 1960. godine. Tvrtka Iskra vu\u010de korijene iz 1946. godine te je i danas prisutna na tr\u017ei\u0161tu. Kroz \u010ditavo razdoblje postojanja nudi \u0161irok spektar proizvoda iz podru\u010dja elektronike, elektrotehnike, telekomunikacija, energetike, automatizacije i tome srodnih proizvodnih grana. &nbsp; Na olovnim [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":17518,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[15],"tags":[],"class_list":{"0":"post-17517","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-mjerni","8":"czr-hentry"},"jetpack_featured_media_url":"https:\/\/crowave.com\/blog\/wp-content\/uploads\/2023\/07\/stevec_iskra_f122_e3_01.jpg","_links":{"self":[{"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/posts\/17517","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/comments?post=17517"}],"version-history":[{"count":2,"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/posts\/17517\/revisions"}],"predecessor-version":[{"id":17535,"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/posts\/17517\/revisions\/17535"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/media\/17518"}],"wp:attachment":[{"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/media?parent=17517"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/categories?post=17517"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/tags?post=17517"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}