Oscillator RC Phase Shift

Oscillators na RC phase-shift suna amfani da network na resistor-capacitor (RC) (Figure 1) don bayar hanyar phase-shift da shi zai iya ba feedback signal. Suke da yawan kula-kula ga frequency da suka yi waɗanda za su iya tabbatar da sine wave mai kyau zuwa yawan abubuwan tafi.

Idan an yi amfani da RC network na musamman, ana fataki da output ta zama mafi girma ɗaya da input a matsayin 90o.

Amma, a cikin al'adun duniya, farkon fase ya zama mafi girma ɗaya saboda capacitor da ake amfani da ita a cikin circuit ba zan iya zama ideal. Koyarren lissafin farkon fase na RC network ya nuna a cikin

Amsa, XC = 1/(2πfC) shine reactance na capacitor C da R shine resistor. A cikin oscillators, wadannan koyarren RC phase-shift networks, da suke da farkon fase na musamman, suke amfani da su don cascading don in ba Barkhausen Criterion.

Wannan misali ce da ake amfani da ita a cikin RC phase-shift oscillator don cascading tare da uku RC phase-shift networks, kowane ta ke bayar farkon fase na 60o, kamar yadda aka nuna a Figure 2.

A cikin wannan, collector resistor RC ya gina limit to collector current na transistor, resistors R1 da R (wanda ke yaɗa zuwa transistor) suka yi voltage divider network, sannan emitter resistor RE ya gina masu yawa. Sannan, capacitors CE da Co su shine emitter by-pass capacitor da output DC decoupling capacitor, respectively. Sannan, circuit ya nuna tare da uku RC networks da ake amfani da su a cikin feedback path.

Wannan arrangemen ce ke gina output waveform ta zama mafi girma ɗaya da 180o a lokacin da yake tashin output terminal zuwa base na transistor. Sannan, wannan signal za a zama mafi girma ɗaya da 180o ta hanyar transistor a cikin circuit saboda farkon fase bayan input da output ya zama 180o a cikin configuration na common emitter. Wannan ke gina net farkon fase ta zama 360o, kuma ya tabbatar da farkon fase condition. Wace ɗaya na hukumomi da za a iya amfani da ita shine tare da uku RC networks, kowane ta ke bayar farkon fase na 45o. Saboda haka, zan iya cewa RC phase-shift oscillators suke amfani da many ways saboda adadin RC networks a cikinsu ba su zama fix. Amma, ya kamata a duba cewa, idan an yi karfi wajen stages, zai tabbatar da kula-kula ga frequency, amma zai juye frequency na output na oscillator saboda loading effect. Expression na general da ya nuna frequency na oscillations da ake samu daga RC phase-shift oscillator shine

Amsa, N shine adadin RC stages da ake form da ita tare da resistors R da capacitors C. Sannan, kamar yadda ake amfani da most type of oscillators, RC phase-shift oscillators suke amfani da OpAmp a cikin section na amplifier (Figure 3). Amma, mode na working ya zama daban-daban, kuma ya kamata a duba cewa, a cikin wannan, farkon fase na 360o da ake samu ta hanyar RC phase-shift networks da Op-Amp working in inverted configuration. Sannan, ya kamata a duba cewa frequency na RC phase-shift oscillators zai iya canzawa tare da kiyasin resistors ko capacitors. Amma, a cikin halittu, resistors suke zama constant sannan capacitors suke gang-tuned. Sannan, idan a duba RC phase-shift oscillators da LC oscillators, ana iya duba cewa, wadannan da suke da adadin components masu yawa. Saboda haka, frequency na output da ake samu daga RC oscillators zai iya canzawa daga calculated value masu yawa. Amma, suke amfani da su a cikin local oscillators for synchronous receivers, musical instruments, and as low and/or audio-frequency generators.

Bayanin: Iyakoki ta harshe, babban articles sune mai share, idana ne da infringement za mu shafi don delete.