B-H Curve Unit

Description

Determination of Energy Band Gap of Silicon, Germanium etc using diodes and light emitting diodes. There are two windings on the specimen (primary and secondary). The primary is fed to low A.C. voltage (50 Hz). This produces a magnetic field H in the specimen. The voltage across R1 (resistance connected in series with the primary) is proportional to the magnetic field. It is given to the horizontal input of the CRO. The A.C. magnetic field induces a voltage in the secondary coil. The voltage induced is proportional to dB/dT (B-flux density). This voltage is applied to a passive integrating circuit. The output of the integrator is proportional to B and fed to the vertical input of the CRO.