PART D

15.
Schering Bridge

It is one of the most widely used ൭.൦. bridges for the measurement of unknown
capacitors, dielectric loss and power factor.

The Fig. shows the connections of
Schering bridge. It can be used for low voltages.
The C, is perfect capacitor to be measured. R, is
series resistance. C, is standard air capacitor
having very stable value. २, and R, are
non-inductive resistances while C, is variable
capacitor.

From the general balance equation,

2,2, = 2, 2,

(sé)
(അവ)
പം. ‏وعد‎ —j@mR] Cy

1
ல, ‏یت‎ -1 (൪,൦൮൩. ഫ്‌ RF © 3 +3

ಜ್ಯಾ പു... ट न ட்ட.
4 R, -/ல1₹3 Cy R, ‏ری‎ त
Tso? ‏ہے‎ ട്ട്‌

Rationalising, 2, = Rs (1+? एर्द्‌ ‏ات أده‎

لع عم بچ و بیغ - ‎നിയം‏

Z = २५|| ‏سے‎

ಎ ಹ 230, ‏وک‎ ८५
“RG -- 2 ott

-j 1 -_ : 1२3 x Ry, - ர்‌
@c, Ri ८६2 Ry, ac;
Ry
− ac, = Re ‏ده‎
‎ಸ್ನ
‎os Cy − Re C2

The equations (1) and (2) gives the required values of C, and ए...

೪2)