Hay bridge

hay`s bridge description for electronics 4th sem in bteup

1. ELECTRONICS INSTRUMENT & MEASUREMENT ELECTRONICS 4 TH SEMESTER

2. HAY`S BRIDGE यह एक AC ब्रिज होता है | HAY`S BRIDGE सर्किट का SELF INDUCTANCE MEASURE करने के काम आता है | यह ब्रिज MAXWELL ब्रिज की ADVANCE फॉर्म होता है | मैक्सवेल ब्रिज केवल मध्यम Q फैक्टर (1 <Q>10) के इंडक्टर के INDUCTANCE MEASURE करने के काम आता है जबकि HAY`S ब्रिज उच्च Q फैक्टर (Q>10) के सर्किट के सेल्फ INDUCTANCE MEASURE करने के काम आता है |

3. CONSTRUCTION OF HAY`S BRIDGE

4. Z1 = R1 + (1/jwC1) Z2 = R2 Z3 = R3 Z4 = Rx + jwLx For Balance bridge , Z1 Z4 = Z2 Z3 So, ( R1 + (1/jwC1 ))( Rx + jwLx ) = R2 R3 (R1 Rx + Lx/C1) + j (w Lx R1 – Rx/w C1) = R2 R3 REAL & IMAGINARY PART COMPARE करने पर R1 Rx + Lx/C1 = R2 R3 --------- (b) wLx R1 – Rx / w C1 = 0 wLx R1 = Rx / w C1

5. Rx = w2 Lx C1 R1 -----(a) समीकरण a का मान समीकरण b में रखने पर एवं दोनों को हल करने पर L x = R2R3C1/( 1+ ω2R1 2 C1 2) Rx= ω2C1 2R2R3R1/ω2R1 2C1 2 The Q Facor of the coil is Q = ωLx/Rx = 1/ ω2R1C1

6. Advantages The advantages of hays bridge are 1. This bridge is used for the unknown inductances to provide a simple expression. It is appropriate for the coil that has a high Q factor than the 10 ohms. 2.For the Q factor, this bridge provides a simple equation. 3.It uses a small resistance value to determine the quality factor.

7. Disadvantages The disadvantages of hays bridge are It is not applicable for the measurement of the coil which has less than 10 ohms Q factor. The balanced equation of the bridge depends on operating frequency and thus the frequency change will influence the measurements. The Q factor is used to determine the main relationship between the energy which is stored & dissipated within the circuit.

8. Applications of Hays Bridge The applications are This bridge is used to determine the self-inductance of the circuit. This is used to overcome the drawback of Maxwell’s bridge. The This bridge circuit is used to measure the high QF (quality factor) in the circuit.