Konstrakshi na Sisimai AC da Farkon Inganci na Sisimai AC

Bridge circuit ba shi wani electrical circuit configuration da ake amfani da ita don kawo masu lafiya daga cikin hanyar yawan resistance, impedance, induction, da capacitance. Akwai bridges kamar Wheatstone bridge, Maxwell Bridge, Kelvin Bridge, da sauransu suna da muhimmanci a kawo masu lafiya daga cikin hanyar yawan abubuwa da suka yi aiki da dalilin sama. Haka ya kamata bayanin yadda bridges take yi aiki:

Wheatstone Bridge

A Wheatstone bridge shi ne electrical circuit da Charles Wheatstone ya bari, kuma ana amfani da ita don samun yawan electrical resistance na musamman a cikin circuit. Wheatstone bridge tana iya samun yawan resistance da dama da za a iya samun ta da wasu instrument kamar multimeter ba.

Circuit din Wheatstone bridge tana da kyau a kan four resistors. Tana da two parallel legs kuma har leg tana da two resistors in series. A third leg tana daɗe a kan biyu parallel legs a matsayin wani point a kan legs. Daga cikin four resistors, zan iya samun yawan wahid mafi tsawon leg. Daga cikin four resistors, R1 da R3 sun fi sani, R2 tana iya gudanar, da Rx tana iya samun ta. Kafin ake gudanar wannan adjustment, tana da electric supply da galvanometer a kan terminal D da terminal B. Kafin ake gudanar value ta adjustable resistor har zuwa lokacin da ratio ta biyu branches resistances tana da same (R1/ R2) = (R3/Rx), da galvanometer tana nuna zero saboda current tana stop flowing through the circuit. Kafin ake balance circuit, tana iya samun yawan unknown resistor da rahotanni. Reading of R3 tana yin direction of the flow of current.

Maxwell’s Bridge

Principle ta working ta Maxwell’s inductance bridge tana da same da Wheatstone bridge. Ba a yi only little modifications a Wheatstone bridge. A bridge na, an da four branches da unknown inductance (L1), a variable capacitor (C4), four resistors and detector instead of galvanometer as shown in the figure. Ana amfani da ita don samun yawan inductance by comparing the unknown value with the standard variable capacitance.

Basic principle ta bridge shine to compensate positive angle phase ta unknown impedance with negative phase ta capacitance by putting it in opposite branch. Kafin a yi haka, potential difference across the detector tana da zero da ba ake yi flow through it. Capacitor C4 da resistor R4 tana daɗe a parallel and the value of both are adjusted so that bridge get balanced.

Kelvin Bridge tana da another modification ta Wheatstone bridge da ake amfani da ita don samun low resistance a range of 1mΩ to 1kΩ with great accuracy. Don precise measurement ta low resistance, high voltage supply and a sensitive galvanometer tana da za su. Kafin ake samun low resistance, resistance ta connecting wires tana da muhimmanci. Wheatstone bridge tana da two additional resistors as shown in the figure. The resistors R1 and R2 tana daɗe a second set of ratio-arm and constructed four terminal resistors. Here R tana unknown and S tana standard resistor. A galvanometer tana daɗe a kan c and d so that resistance ta connecting wire r tana da za su affect the measurement value. Under the balance condition, galvanometer tana nuna zero and no current tana flow through the circuit. Equation at balance condition is:

Hay’s Bridge Circuit

Hay’s bridge tana da another variation ta Maxwell’s bridge circuit. A Maxwell’s circuit resistance tana daɗe a parallel to capacitor where as, a Hay’s circuit, the resistor tana daɗe a series with the standard capacitor as shown in the figure. It is very useful if the phase angle ta inductive impedance tana da yawa, which could be overcome by taking a low resistance in series.

Anderson’s Bridge

Anderson Bridge tana da modified version ta Maxwell’s inductor capacitance bridge. Ana amfani da ita don samun self-inductance a coil by using standard capacitor and resistors. Muhimman fa'idar bridge na shine ba ake buƙata bridge da frequency. To balance the bridge by steady current, variable resistance r tana daɗe a gudanar and AC source tana daɗe a replace by battery and headphone by moving coil galvanometer. Kafin ake balance bridge, potential at terminal D tana same with potential at E. Flow of current a respective branches tana denoted by I1, I2, and I3 as shown in the figure.

Diode Bridge Circuit

It is a bridge circuit having an arrangement of four diodes that gives the same output polarity for every input polarity. Diode bridge circuit which also called bridge rectifier is used where ever there is a need to change alternating current into direct current. It is also used to detect the amplitude of radio signals. When the positive terminal of the input is connected to the upper left and negative to the lower right, the current flows from upper supply terminal to the output flowed by red path and returns back to the lower supply terminal through the blue path as shown in the figure.