AnsweredAssumed Answered

DDS e.g. AD5934 to be used with variable reluctance sensor?

Question asked by roi on Apr 20, 2018
Latest reply on May 9, 2018 by musach

May I please ask for some expert advice before I go and break my back trying? I have numbered the questions in priority order.

1. Would it work to connect a variable reluctance sensor as the "coil" to one of your interface circuits e.g. for impedance measurements as the AD5934.

Background to question:

In applications when variable reluctance (VR) sensors are used for sensing speed or position the main disadvantage is that they will not work at low speeds or with large air gaps. The problem with these sensors is that:

a) They need to be mounted very close to the pole wheel (small air gap)

b)  They do not give any signal at low speeds. 

My hope is that one could use one of your DDS to detect the teeth of a tooth wheel (presence of a metal teeth or not). 

VR sensor basic data

I made some measurements (with a multimeter) of our VR sensors and the inductance is approx 880mH and this change approx 2-10mH when the tooth is there or not. The resistance is approx. 1k but temperature of the sensor may in extrem cases vary between -40degC to 150 degC so the resistance will change accordingly.

More questions

2. Will the LDC survive the induced voltage when the tooth wheel starts spinning faster? 

3. Could you please advice of what device and components to use?

Thanks in advance

 

Outcomes