Oscillator ta Farko: Me ke Nana? (Kuma Yadda Ake Yi)

فیلڈ: Karkashin Kuliya da Dukkana

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Misalai na Relaxation Oscillator?

Relaxation oscillator shine yadda karkashin jirgin elektronikin da zan iya gina alama da ba da sinuwa a kan ci gaba. An samun relaxation oscillator ta Henri Abraham da Eugene Bloch a lokacin Yakin Duniya 1, tare da amfani da vacuum tube.

Oscillators suna cikewa a matsayin duwatsu; linear oscillators (don sinuwa) da relaxation oscillators (don alamomin da ba su sinuwa).

Yana da kyau a bayyana alama da ci gaba da shi ne a fili don alamomin da ba su sinuwa kamar triangular, square, da rectangular waves a kan ci gaban.

Tushen relaxation oscillator ya kamata yana da muhimmin abubuwa masu karfi kamar transistor, Op-Amp, ko MOSFET da kuma abubuwa masu sauki kamar capacitor da inductor.

Don in gina cycle, capacitor da inductor ke yi aiki da sauransu. Kuma frequency na cycle ko period of oscillation ana nufin da time constant.

Me Yadda Ya Kammala Relaxation Oscillator?

Relaxation oscillator yana da abubuwa masu sauki kamar capacitor da inductor. Wadannan abubuwa suna dauri da hanyar source da kuma kawo da load.

Shape na alaman ci gaban relaxation oscillator ana nufin da time constant na circuit.

Babu nan za a fahimtar yadda relaxation oscillators ke kammala ta haka don misali.

A nan, an kula ta ake kawo da tushen kasa a kan tushen kasa da baturiya. Wannan kabilu na iya a bayar da flasher kabilu ko RC relaxation oscillator.

Baturiya ta ake kawo da kula har zuwa harshe. A lokacin da ake kawo da kula, tushen kasa ta zama a cikin yadu.

Idan kula ta sami shi da tsari, ta ake gaba da tushen kasa. Saboda haka, a lokacin da ake gaba da kula, tushen kasa ta fi shi.

Idan kula ta gaba, ta bazu ne ake kawo da ita daga masu kawo. Kuma tushen kasa ta zama a cikin yadu.

Saboda haka, yanayin da ake kawo da gaba da kula ta ci gaba da kadan.

Lokacin da ake kawo da kula ta nuna da wani tsari. Kuma tsarin ta dogara da darajar da ke harshe da kula don kabilu na RC.

Saboda haka, tsari da tushen kasa ta yi ta nuna da darajar da ke harshe da kula.

Wata na tushen kasa suna da wannan hakan:

rc relaxation oscillator waveform — Wata na RC Relaxation Oscillator

Don in kontrola wata na fadada, ana amfani da abubuwa da ba da siffofi a cikin kabilu.

Diagramma na RC Relaxation Oscillator

Diagramma na relaxation oscillator kabilu ta da abubuwan da ba da siffofi don in gina wata na fadada. Idan a amfani da abubuwan da ba da siffofi, relaxation oscillator ya kula da tsohon diagramma.

Op-Amp Relaxation Oscillator

Anka Op-Amp relaxation oscillator tana da sunan astable multivibrator. Tana amfani a kan tsara wasu square waves. Shaida na cikin circuit diagram ta Op-Amp relaxation oscillator tana cika a fayilolin da ke rarrabe.

Circuit din tana da capacitor, resistors, da kuma Op-Amp.

Terminal non-inverting ta Op-Amp tana kashe da RC circuit. Saboda haka, voltage ta capacitor VC tana da dama da voltage a terminal non-inverting V- ta Op-Amp. Da inverting terminal tana kashe da resistors.

Idan Op-Amp tana amfani a kan positive feedback, kamar yadda ake nuna a cikin circuit diagram, circuit din tana da sunan Schmitt trigger.

Idan V+ tana mafiya zuwa V-, output voltage tana +12V. Da kuma idan V- tana mafiya zuwa V+, output voltage tana -12V.

Don initial condition, a lokacin t=0, zaka iya yi shakka cewa capacitor tana da discharge. Saboda haka, voltage a terminal non-inverting tana V-=0. Da kuma voltage a inverting terminals V+ tana da dama da βVout.

$\beta = \frac{R_2}{R_2+R_3}$

Don samun yadda ake yi aiki, za mu iya ce ta R2 da R3 suna da duka. Saboda haka, β=2 da kuma βVout=6V. Saboda haka, a kan gaba zai shiga da karfi zuwa 6V.

$t=0; \quad V- = 0V; \quad V+=+6V; \quad V_{OUT}=+12V$

A cikin wannan yanayi, V+ yana da kyau da V-. Saboda haka, ci gaba na Vout=+12V. Da kuma a kan gaba ya faruwar da karfi.

Idan ci gaban a kan gaba yana da kyau da 6V, V- yana da kyau da V+. Saboda haka, ci gaba na ci gaba yana canza zuwa -12V.

$V- > 6V, \quad V+=6V, \quad V_{OUT}=-12V$

A cikin wannan lokacin, zama shi da tsari ta kan voltage na inverting terminal. Saboda haka, V+ = -6V.

Tana, capacitor ya fitar da maida har zuwa -6V. Idan voltage na capacitor yana daɗe da -6V, V+ tana da take da V-.

$V+ = -6V; \quad V-<-6V, \quad V+>V-$

Saboda haka, output voltage tana zama shi da tsari ta -12V zuwa +12V. Tana, capacitor tana kawo fitar da maida.

Saboda haka, cycle na fitar da maida da capacitor tana bayyana square wave na periodic da repetitive a kan output terminal, kamar yadda aka nuna a taurarin.

op amp relaxation oscillator waveform — Op-Amp Relaxation Oscillator Waveform

Tashin kwayoyin karamin karamin kwayoyi ya kunshi da lokacin da karamin karamin yake zama da karamin karamin yake rage. Kuma lokacin da karamin karamin yake zama da karamin karamin yake rage ya kunshi da lokacin da tsarin RC yake rage.

UJT Relaxation Oscillator

An amfani da UJT (unijunction transistor) a matsayin yanayin da take daidai a maimaitar relaxation oscillator. Tashkar da tushen UJT relaxation oscillator ta shahara a bayanin da ke kusa.

An haɗa cikakken UJT da karamin karamin da karamin karamin.

Amsa da za mu iya ce cewa karamin karamin bai rage ne. Saboda haka, ci gaba na karamin karamin ba a kan zero ba.

$V_C = 0$

A cikin wannan halin, UJT yana cire OFF. Kuma karamin karamin ya fara zama da karamin karamin R daga abubuwan da aka bayyana da karamin karamin.

$V = V_0 (1-e^\frac{-t}{RC})$

Kondansar tana da shiga har zuwa idan ya samu hanyar karamin tsari mai yawa VBB.

Idan tsari a kan kondansar ya fi yawa da tsari mai karfi, zai iya sa UJT suka faɗi. Kuma kondansar zai taɓa shiga da kuma zai fara fitowa a kan R1.

Kondansar zai taɓa fitowa har zuwa idan tsarin fitowar ta fi yawa da tsari mai faduwar (VV) na UJT. Ba dangane, UJT zai taɓa faɗi da kuma zai fara shiga kondansar.

Don haka, yanayin shiga da fitowa a kan kondansar zai haɗa wata cuta mai gaba-gaba a kan kondansar. Da kuma tsari zai cikin R2 a lokacin fitowa kondansar, amma za su zama zero a lokacin shiga kondansar.

Tsarin tsari a kan kondansar da R2 an bayyana a tunani a nan.

ujt relaxation oscillator waveform — UJT Relaxation Oscillator Waveform

Tsari na UJT Relaxation Oscillator

Takarda na oscillator ta rarrabe da ita ce kawai mafi girma a tafin kasa da fitarwa kan kapasita. A cikin ci gaba na RC, takarda na tafin kasa da fitarwa kan kapasita ce ne da yake shiga da tsari.

Takarda na Op-Amp Relaxation Oscillator

A cikin Op-Amp relaxation oscillator, R1 da C1 suna yi muhimmiyar rawa wajen takarda na rarrabe. Saboda haka, don takarda mai kadan, muna bukata lokacin da ya fi kasa da fitarwa kan kapasita. Kuma don lokacin da ya fi kasa da fitarwa, muna bukata R1 da C1 masu yawan gadi.

Duk da haka, R1 da C1 masu yawan kadan suna yi takarda mai yawa na rarrabe.

Amma, a cikin karkashin takarda, R2 da R3 suna yi muhimmiyar rawa. Saboda waɗannan mutanen R suka zama na musamman a cikin tsari na voltage na kapasita, kuma kapasita zai kasa har zuwa tasirin voltage na.

Idan tasirin voltage na baya, lokacin da ya fi kasa ce kadan. Duk da haka, idan tasirin voltage na yawa, lokacin da ya fi kasa ce yawan gadi.

Saboda haka, takarda na rarrabe tana da yake shiga da yadda R1, R2, R3, da C1. Kuma formula na takarda na Op-Amp relaxation oscillator shine;

$f = \frac{1}{2 \times R_1 \times C_1 \times ln (\frac{1+k}{1-k})}$

Amsa,

$k = \frac{R_2}{R_2+R_3}$

A cikin yawan duka, R2 da R3 suna da shi a zama don bayyana da takarda.

$R_2 = R_3 = R$

$k = \frac{R}{2R} = \frac{1}{2}$

$f = \frac{1}{2 \times R_1 \times C_1 \times ln (\frac{1+\frac{1}{2} }{1-\frac{1}{2} })}$

$f = \frac{1}{2 \times R_1 \times C_1 \times ln (3)}$

$f = \frac{1}{2.2 \times R_1 \times C_1}$

A cikin ɗaukar R1 da C1, zan iya samun adadin da Op-Amp relaxation oscillator yake tafi.

Adadin UJT Relaxation Oscillator

A cikin UJT relaxation oscillator, kuma adadin ya yi amfani da RC circuit. A cikin diagram na circuit ta UJT relaxation oscillator, R1 da R2 suna da amfani a hanyar ƙwarewa mai tsarki. Kuma adadin tafi na ya yi amfani da R da C.

Shirin adadin UJT relaxation oscillator shine;

$f = \frac{1}{RC ln(\frac{1}{1-n})}$

Idan;

n = Intrinsic stand-off ratio. Da kuma irin n ya kasance bayan 0.51 zuwa 0.82.

$n = \frac{R_1}{R_1 + R_2}$

Don sami da zama UJT, ita ce kyau da mu karin haɗin kai:

$V = n V_{BB} + V_D$

Idan,

VBB = haɗin kai

VD = haɗin kai na diodoci na ƙarfin da ke bayan gurbin da ke bayan base-2

Yadda ake sauti cikin hanyar R yana da muhimmanci daga wani tsawon hanyar zuwa wani.

$max = \frac{V_{BB}-V_P}{I_P} \quad min=\frac{V_{BB}-V_V}{I_V}$

Idan,

VP, IP = babban fasahar kashi da kafin kasa

VV, IV = yankin fasahar kashi da kafin kasa

Tsarin Tashar Fasahar Kashi na Tsarin Tashar Fasahar Kashi

A cikin tsarin tashar fasahar kashi, R2 da R3 suna da ma'ana mafi yawa. Saboda haka, daidai da tsarin tashar kashi;

$V_+ = \frac{V_{out}}{2}$

V– ya samu da ohm’s law da kuma taurar zabi na capacitor;

$\frac{V_{out}-V_-}{R} = C \frac{dV_-}{dt}$

Aka bi yawan halayyar taurar zabi haka; halayya mai sauƙi da halayya mai gaba-gaban.

Don halayya mai sauƙi, V- ita ce karamin ɗaya. Yana iya hasashen V– = A. Saboda haka, zabe ta karamin ɗaya shi ita ce zero,

$\frac{dV_-}{dt} = \frac{dA}{dt} = 0$

$\frac{A}{RC} = \frac{V_{out}}{RC}$

$V_{out} = A$

Don samun yadda amsa mai mahimmanci, amfani da Laplace transform na wannan kungiyar:

$\frac{dV_-}{dt} +\frac{V_-}{RC} = 0$

$V_- = Be^{\frac{-1}{RC}t}$

V– shi ne jami'a ta amsa mai mahimmanci da amsa mai gaba.

$V_- = A + Be^{\frac{-1}{RC}t}$

Don sami da B, yana da ita ce ake duba kadan bayanai.

$t=0; \quad V_{out} = V_{dd}; \quad V_-=0$

$0 = V_{dd} + Be^0$

$B = -V_{dd}$

Kuma, zai fada na V- shi ne;

$V_- = V_{out} - V_{dd} e^{\frac{-1}{RC}t}$

Comparator da Op-Amps

Comparator tana amfani da ita a kan Op-Amp. Daga cikin Op-Amp, comparator suna gina a yi rail-to-rail.

Comparator tana da wakar tsawon kadan da yake da fall time a kan Op-Amp. Saboda haka, comparator tana da muhimmanci a kan Op-Amp a filayin oscillator circuit.

A cikin Op-Amp, tana da outputs na push-pull. Saboda haka, idan kana amfani da Op-Amp, ba za a buƙata pull-up resistor ba. Amma idan kana amfani da comparator, ya kamata a yi amfani da pull-up resistor.

Ayyuka da Relaxation Oscillators ke Amfani Da Su

Relaxation oscillators ana amfani da su don gina internal clock signal a kan waɗannan digital circuit. Suna amfani da su a cikin ayyukan da aka bayyana a nan.