A zamanin yau, PLC na iya karɓar encoder da siginar firikwensin ba tare da amplifier ba, don haka menene nishaɗin "tushen" da "magudanar ruwa"? Fitowar PLC kawai za ta sami ma'anar "tushen" da "leakage".

A gaskiya, ban da PLC na Japan, ba lallai ba ne don wasu PLC su yi amfani da gajarta kamar "source" da "drain", amma PNP da NPN za a iya amfani da su kai tsaye.

PNP layin jama'a ne mara ƙarfi, kuma NPN babban layin jama'a ne. Muddin wannan haɗin ya yi daidai, da alama ba kome ba idan an juya ma'anar "tushen" da "magudanar ruwa". Duk da haka, wata ma'anar "tabbataccen tunani da tunani mara kyau" ma kuskure ne, wanda zai sa alamar ta juya.

Ma'ana mai kyau da kuma mummunan tunani

A cikin nau'ikan nau'ikan PNP, tashar wutar lantarki ta gama gari da sigina tana a ƙaramin matakin 0V. Lokacin da shigarwar ya kasance a ƙaramin matakin, babu bambanci na ƙarfin lantarki tare da tasha ta gama gari, don haka babu haɓakar siginar sauyawa (yawan dijital shine 0). Sai kawai lokacin da shigarwar ya kasance a babban matakin, akwai bambancin wutar lantarki tare da tashar gama gari kuma ana fitar da siginar ƙararrawa a babban matakin. Wannan yanayin dijital (yawan dijital shine 1) wanda ke da tasiri lokacin da siginar ta kasance a babban matakin ana kiranta PNP tabbatacce dabaru.

A cikin da'irar NPN, tashar gama gari na samar da wutar lantarki da siginar yana a babban matakin (halayen da'irar amplifier). Lokacin da shigarwar ya kasance a matsayi mai girma, babu bambanci tsakanin shigarwar da fitarwa, don haka babu fitarwar siginar sauyawa (yawan dijital shine 0). Sai kawai lokacin da shigarwar ta kasance a ƙananan matakin (forming a mazurari), ana samun fitarwar siginar sauyawa, kuma wannan sigina yana da tasiri (dijital quantity 1) yanayin dijital a ƙananan matakin, wanda ake kira NPN negative Logic.