Inductor Circuit Simulation: Understanding Current Rise and Voltage Output

In summary, the conversation is about understanding an inductor circuit and simulating its behavior. The simulation shows that the inductor current should slowly increase from 0A to 500mA, but this is not seen in the waveform. The time constant for the circuit is also discussed and an equation is provided to calculate the current. Substituting values, the calculated current matches the simulated current. Finally, it is recommended to zoom into the first few microseconds of the transient waveform to see the LR time constant and to use specific parameters in the simulation to see the current rise over a specific time period.
  • #1
PhysicsTest
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TL;DR Summary
To understand the inductor circuit.
I am trying to understanding the inductor circuit. I have drawn the below circuit and try to simulate
1635602554158.png

The Inductor current comes to 500mA and Vout is 5V as per simulation. The current in inductor should slowly increase from 0A to 500mA but i cannot see that in the waveform. Is my understanding correct?
 
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  • #2
PhysicsTest said:
but i cannot see that in the waveform
Neither can we. What waveform ?
Do you have some equations to describe the behaviour of your circuit ?

##\ ##
 
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  • #3
I'm not sure about "slowly".
The time constant for this circuit is L1/R1 = 10uSec.
 
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  • #4
1635604571909.png

This is the output waveform i can get. Ok now i started writing the equation for the circuit.
##i(t) = \frac{V} {R} (1 - e^{\frac{-Rt} L})##
Substituting the values
##i(1) = 5/10*(1 - e^{-10^5}) ##
##i = 0.5A##. The answer is matching.
 
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  • #5
So zoom into the first few us of the transient waveform to see the LR time constant...
 
  • #6
The DC analysis sets up 500 mA before the run.
You must use; V1 pulse; initial=0V; Von=5V; Tdelay=5usec;
and .TRAN stop time = 100 usec.
Then see the current rise over about 50 usec.
Inductor.png
 
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