Generation of magnetic fields
Generation of magnetic fields by means of field coils (e.g. Helmholtzspulen)
Many areas of research and development or of industrial measuring and test engineering require the use of magnetic fields. Generally, coils of most varied designs and types with fix inductivity are implemented for these purposes. An example is what is referred to as Helmholtz coil, which is encountered in various EMC-relevant standards...
Electro-dynamic vibration exciter
Operating electro-dynamic shakers by means of current amplifiers
Two electro-dynamic vibration exciters with an impedance of Z = 4 Ohm + 1.6 mH are each actuated by a power amplifier with constant current (maximum 8 Ap, gain = 1 V / 1 A) ) in a frequency range from 10 Hz to 500 Hz. The phase shift between output voltage and output current must not exceed +/- 2° and the amplitude response of the amplifiers should be nearly identical (difference < 0.05 dB) ...