Proximity Detector

– (a) a reed switch that manipulates a connected or disengaged switch based on a magnetic field
– (b) RF-lost due to a metal absorbing magnetic field (frequency 40-200 kHz) resulting in the RF detector down due to LC resonance circuit loading in the oscillator
– (c) The capacitance detector observes the change of capacitance by the nonconducting material
– (d) beam of focused light

Figure 3.41 Some proximity sensors

Transducer Resolver and Inductosyn
– a motor-generator pair: the resolver and the transmitter are used to measure the angle of a rotational motion
– stator coils as receivers are placed at different angles

• 3 stator: syncho
• 2 stator: resolver

– linear version (inductosyn) 90 degree angle difference obtained with difference 1/4 winding

Figure 3.40 Construction of Resolver – Inductosyn and the resulting signal