how to simulate the inductor coil in orcad?

hi all am trying to simulate a proximity sensor circuit in or cad... in practical if the metal object come in front of the inductor coil means the amplitude of the coil will get decrease.. so here i need to know how can i bring the similar effect while i simulating the proximity sensor circuit in or-cad 16.3.. please help any one?

I doubt if this can be simulated in pSpice. I am not aware of any simulation models for proximity effect

You need to model proximity effect in electrical form for simulation? What do you mean by amplitude of inductor coil?

You would need to measure an actual coil an make your own model. My guess is the coil becomes very lossy so would be modeled by a low value resistor across the inductor.

Keith

Non-ferromagnetic objects can be represented by a RL series circuit in parallel to the main inductance. Values of L and R depend on distance, size and resistivity of the object. Generally, you get a reduction of total inductance together with resistive losses.

Ferromagnetic objects also increase the main inductance of the coil.

For a quantitative simulation, you either should measure the impedance variation of a real coil with an LCR meter or determine the coil parameters in an AC magnetic simulation with a suitable tool, e.g. Quickfield Student Edition.

is it possible to bring the inductance variation effect when moving the metal target in front of the coil in Quickfield Student Edition simulation..

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In my proximity circuit am having the oscillator with the following specification that s my inductor coli may have the number of turns = 40,inductance = 38uH,capacitor = 820pF,..in practical while i checking my inductive sensor the oscillating frequency will be = 901 khz and the amplitude(peak to peak) of frequency will be approximately = 20 v.. if i bring the metal target in front of the sensor means the.. the amplitude of the frequency will get reduced.. so here how can i bring this same effect in oracd?

It's possible, to determine all coil impedance variations (inductance and losses) in an AC magnetic simulation (preferably axisymmetric), but you need to become familiar with the model design and measurement methods.

I guess, that a simple variable loss factor model will be sufficient, just placing a variable (by simulation parameter) resistor in parallel to the coil.

I have simulated these inductive sensors for a client some years ago, using Sonnet EM simulation. If the metall object is a good conductor, the main effect is a change in inductance (not loss).

hello mr. volker_muehlhaus
can you able to guide me to simulate the inductive sensor,,

Reviewing your previous statements, the exact simulation objective isn't clear, I think. Is it quantitative simulation of a given sensor geometry and material combination? This would require a geometry definition and usage of an AC magnetic or EM solver. Or are you just intending a principle functional simulation? In my opinion, sufficient how-to hints have been already given. You didn't yet show your present oscillator circuit, by the way.