Uvuti wa Kingo na Ukingo wa Thevenin: Ni nini?

Ni ni Thevenin’s Theorem (Thevenin Equivalent)?

Sheria ya Thevenin (iliyokubaliwa kama Helmholtz–Thévenin) inasema kuwa circuit lenye vifaa vya chanzo cha umeme, chanzo cha mizizi na upimaji unaweza kupigwa kwenye combination equivalent ya chanzo cha umeme (VTh) in series na upimaji moja tu (RTh) ulioelekezwa kwenye load. Circuit hii iliyopunguzwa inatafsiriwa kama Thevenin Equivalent Circuit.

Sheria ya Thevenin ilianzishwa na mhandisi wa Kifaransa Léon Charles Thévenin (kwa hiyo jina).

Sheria ya Thevenin hutumika kutofautisha circuit ya umeme yenye umbo la nguvu kwenye Thevenin equivalent circuit yenye umbo la chache. Thevenin equivalent circuit ina Thevenin resistance na Thevenin voltage source iko na load, kama inavyoelezwa katika picha chini.

Thevenin resistance (Rth) inakujulikana kama equivalent resistance. Na Thevenin voltage (Vth) ni open-circuit voltage kwenye vitu vinavyovutia load terminals.

Sheria hii inafaa kwa circuits linear tu. Ikiwa circuit una viwango kama components za semiconductors au components za gas-discharging, huwezi kutumia Thevenin’s Theorem

Thevenin Equivalent Formula

Thevenin equivalent circuit ina equivalent voltage source, equivalent resistance, na load kama inavyoelezwa katika picha ya juu figure-1(b).

Thevenin equivalent circuit ina loop moja tu. Ikiwa tutumia KVL (Kirchhoff’s Voltage Law) kwenye loop hii, tunaweza kupata current inayopita kwenye load.

Kulingana na KVL,

Jinsi ya Kutafuta Thevenin Equivalent Circuit

Thevenin equivalent circuit ina Thevenin resistance na Thevenin voltage source. hivyo basi, tunapaswa kupata values hizo mbili kwa Thevenin equivalent circuit.

Thevenin Equivalent Resistance

Ili kupata Thevenin equivalent resistance, ondoa power sources zote kutoka kwenye circuit asili. Na voltage sources zinapewa short-circuited na current sources zinapewa opened.

Hivyo basi, circuit iliyobaki ina upimaji tu. Sasa, hesabu total resistance kati ya connection points open kwenye load terminals.

Equivalent resistance inahesabiwa kwa kutumia series na parallel connections ya resistances. Pata value ya equivalent resistance. Hii resistance inajulikana kama Thevenin resistance (Rth).

Thevenin Equivalent Voltage

Ili kupata Thevenin equivalent voltage, impedance ya load inapewa open-circuited. Pata open-circuit voltage kwenye load terminals.

Thevenin equivalent voltage (Veq) ni sawa na open-circuit voltage ime measured kwenye vitu vinavyovutia load. Value hii ya ideal voltage source inatumika kwenye Thevenin equivalent circuit.

Thevenin Equivalent Dependent Source

Ikiwa network ya circuit ina dependent sources, Thevenin resistance inahesabiwa kwa njia tofauti. Katika hali hii, dependent sources zinazozingatia. Huwezi ondoa (open au short circuit) voltage au current sources.

Kuna njia mbili za kupata Thevenin resistance katika hali ya dependent sources.

Njia 1

Katika njia hii, tunapaswa kupata Thevenin voltage (Vth) na short-circuit current (Isc). Weka values hizo katika equation ifuatayo ili kupata Thevenin resistance.