Another Torsion

Photoelectric Magnetometer



Institute of

Geophysics of the CAS, Prague, Czech Republic


For proving of functionality of integral

sensor – heating system unit, realization of which is being in

progress at Polom observatory, simple TPM was constructed.

Optical source is laser diode. Optical transducer works in baseband.

It is realized with antiparallel PIN photodiodes and FET preamplifier

of Kudelski type. Current output is fed to electronic box to regulator

amplifier of Akerberg-Mossberg topology, which serves as

TransImpedance Amplifier, integrator, damper and output amplifier.

Feedback is realized by one-turn of Calibration Coil of the Bobrov

element. Gain of the system (V/nT) is given by series resistor between

TIA and CC.

Heating is realized as continuous regulation via Phase to Amplitude

Conversion property of switched H-bridge.