Dynamic hysteresis loop measurer for magnetic materials - uses stimulation and detection coils, power operational amplifier, field detecting shunt, peak detectors, summer and PI element

摘要

The stimulation (2) and detection (3) coils are driven by a power operational amplifier (5) controlled by a function generator (4). A voltage representing the magnetic field strength is detected by a shunt (6) in the stimulation circuit. The detector coil feeds the non-inverting input of the amplifier via an integrator. The shunt is connected to positive and negative peak detector (9,10) inputs (7,8). The peak detector outputs are connected to a summer (11); one via a switch (12). The summer drives a proportional-integral element (13) whose output is connected to the integrator's (14) non-inverting input. ADVANTAGE - Enables defined stable voltage to be achieved at output of power operational amplifier.