Me kadan Woltan Kontrolla Oscillator?

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فیلڈ: Dakilin ƙasashen ilimi

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Mai Da Zama Da Voltage Controlled Oscillator?

Takarda Voltage Controlled Oscillator

Voltage controlled oscillator (VCO) shine da takarda oscillator wanda frequency ta koyar da input voltage.

Sana'ar Tattalin Aiki

An samun VCO circuits tare da amfani da manyan components na voltage control masu electronics kamar varactor diodes, transistors, Op-amps, etc. A nan, zan iya bayyana sana'ar tattalin aiki na VCO tare da Op-amps. Diagram ta circuit ya shiga haka.

Output waveform ta VCO yana cikin square wave. Idan an sanin cewa output frequency yana kan control voltage. A cikin circuit ta, Op-amp na farko zai aiki a matsayin integrator. An yi arrangement na voltage divider a nan.

Saboda haka, adadin dala daga control voltage wanda ake bayar zuwa terminal na positive na Op-amp 1. Level mafi tsawon voltage yana da shi a terminal na negative. Wannan shine don tabbatar da voltage drop across resistor, R 1

Idan MOSFET yana cikin on condition, current mai sauƙi daga R1 resistor ya fi MOSFET. R2 na da resistance na dala, voltage drop sama da current na biyu saboda R1. Saboda haka, extra current yana jiye capacitor. Op-amp 1 ya kamata bayar output voltage na ciki don jiye wannan current.

Idan MOSFET yana cikin off condition, current mai sauƙi daga R1 resistor ya fi capacitor, ya faru. Output voltage da aka samu daga Op-amp 1 a lokacin da yake ya zama falling. Saboda haka, triangular waveform yana samu a cikin output na Op-amp 1.

Op-amp na biyu yana aiki a matsayin Schmitt trigger. Yana gina triangular wave daga Op-amp na farko a matsayin input. Idan input voltage yana fi threshold level, output na Op-amp na biyu zai VCC. Idan yana ƙarin, output zai zero, wanda yake yana ba da square wave output.

Misali na VCO shine LM566 IC ko IC 566. Wannan ita ce 8 pin integrated circuit wanda zai iya samu double outputs-square wave da triangular wave. Internal circuit ya shiga haka.

Control Frequency a Voltage Controlled Oscillator

Manyan forms na VCO suna da amfani da su. Zai iya cikin RC oscillator ko multi vibrator type ko LC ko crystal oscillator type. Amma; idan yana cikin RC oscillator type, oscillation frequency na output signal zai cikin inversely proportional to capacitance as

A cikin LC oscillator, oscillation frequency na output signal zai cikin

Saboda haka, muna cewa idan input voltage ko control voltage yana ɗauki, capacitance yana ƙasa. Don haka, control voltage da frequency na oscillations suna cikin directly proportional. Wannan shine, idan wata yana ɗauki, muka ɗauka.

Wannan figure yana nuna sana'ar tattalin aiki na voltage controlled oscillator. A nan, muna iya neman cewa idan nominal control voltage wanda ake nufin VC(nom), oscillator yana aiki a free running ko normal frequency, fC(nom).

Idan control voltage yana ƙara daga nominal voltage, frequency yana ƙara, kuma idan nominal control voltage yana ɗauki, frequency yana ɗauka.

Varactors diodes, wadanda su ne variable capacitance diodes wadanda suka da amfani a manyan ranges, suna amfani don samun variable voltage. A low-frequency oscillators, charging rate na capacitors yana canzawa tare da voltage controlled current source.

Abubuwan Voltage Controlled Oscillator