A C Bridge Alternate Current Bridge A Vibration

A. C. Bridge Alternate Current Bridge

�������� (A • �������������� • Vibration Galvanometer (����� sensitivity ��� ) -���� moving coil type galvanometer (������ 100 H -���� moving magnet type galvanometer (300 Hz– 1 k. Hz) • Headphone (telephone) (������� AF , > 800 Hz)

• General moving coil milli-ammeter with Copper Oxide Rectifier (������� 40 Hz – 1 k. Hz) • Heterodyne ���� Beat-tone detector (������� > 3 k. Hz) • An Electrodynamometer (������ 25 – 125 Hz) • ���� (amplifier) ����������

Vibration Galvanometer at the left cost $150 in 1926. It was designed for the detection of small alternating current signals, and would produce a deflection of 1 mm on a scale 1 m distance with a current of 0. 025 microamperes. The original purchase included a lamp and scale for making observations. The galvanometer was designed to act as a null detector for inductance and impedance bridges, and would respond to frequencies between 50 and 80 Hz, while giving the best response at 60 Hz. The instrument was considerably more sensitive than the telephone receiver customarily employed with such bridges at these low frequencies. http: //physics. kenyon. edu/Early. Apparatus/Electrical_Measurements/Kenyon. html

Head phone

Similar – Angle Bridge • ������ Impedance ��� Capacitive Circuit • �������� Capacitance Comparison Bridge ���� Series Resistance Capacitance Bridge

Maxwell Bridge • �������� Inductance • ������� Maxwell – Wien Bridge

Opposite - Angle Bridge • ������� Inductive Circuit • �������� Hay Bridge

Wein Bridge • �������� Impedance ��� Equivalent – Series Components (������ ) ��� Equivalent – Parallel Components (���� )

• ������� Equivalent Series Components ������ Impedance ������� c-d • ������� Equivalent Parallel Components ������ Impedance ������� b-d

• ������ Equivalent Parallel Components (�� Z 3) ���

• ������ Equivalent Series Components (�� Z 4) ����