Chris Chapman's Seismic and Magnetic System Designs and Circuits

Latest Lehman Design

Enhanced AS-1 electronic circuit.

MuVentures Schools Seismometer

Magnetic-damping alternative for the AS-1 seismic sensor

Lehman Design (With suggestions for sensor- and damping-designs that apply equally well to vertical and horizontal instruments.)

Moving coil sensor based on speaker design.

Piezo-disk Seismic Sensor Design

LVDT Seismic System

Amplifier-Filter Circuit

Distance Sensor Calibration Mechanism

Graphite-Levitation Seismic Sensor


Suggested Links to Magnetometer Sites

Differential Photo Detector

Concise Summary of Seismic Waves