modified 6 years ago

Is it a simulation mistake in RL circuit

00:52:34

F = 1000 Hz
R = 100 Ohm
L = 0.0159 H

X_L = 2 * PI * F * L = 99.852 Ohm ~ R

Z = sqrt(R^2 + X_L^2) = 100 * sqrt(2) = 141 Ohm

arctg(X_L/R) = arctg(1) = 45 degree

If I am right then the current should lag from the voltage by 45 degree. But simulation shows different result.

What is wrong with that?

published 6 years ago

kiani

6 years ago

The voltmeter on EC does play up, it keeps jumping arrows... But when it does it corrects it by changing the direction of another voktsge.. So kirchoff hs law still holds.... Measure the votlage differently if you sre checking phase.. Yiu"ll get used to it, it used to really bother me for a few months.

kiani

6 years ago

Chk. This. Hope it helps. http://everycircuit.com/circuit/6034974835474432

af_mm

6 years ago

@kiani thanks a lot for your comment and your example. If I understand right then you meant that voltage meter and current meter have directions (arrows and plus/minus signs).Sometimes they change their direction that makes the comparison process complicated. To solve this problem you suggest to use an operation amplifier in order to explicitly specify the needed polarity. I have updated my circuit. I do not understand why I do not see 45 degree lag of the current against voltage...could you explain me, please?

kiani

6 years ago

Right...cause you are measuring the wrong voltage...check this, http://everycircuit.com/circuit/5408970869833728

kiani

6 years ago

Also check this....http://everycircuit.com/circuit/4971840196575232

kiani

6 years ago

The 45 ° is true for perfect inductor with no resistance, . Right!?

westelaudio

6 years ago

http://everycircuit.com/circuit/4813510522175488

lenzrulz

6 years ago

@westelaudio, thank you for sharing your link, very informative...👍

af_mm

6 years ago

Dear @kiani and @westelaudio, thank you very much for your explanations and your time. From your comments I have made the following conclusions: 1) Current and voltage meter have directions (plus/minus signs and arrows). Both of them sometimes change their directions. 2) To measure a phase it is important that directions of current and voltage meter have to be the same. 3) To manually set current meter and voltage meter's directions we can use an operation amplifier.

af_mm

6 years ago

@kiani, Yes, it is right. I know that real inductors have their own active resistance due to a resistance of a wire from which they are made. The inductor of EveryCircuit is perfect and does not have its own active resistance. Hence, the resistor R = 100 Ohm of my circuit includes the active resistance of the inductor. I specially chose R = 100 Ohm and X_L = 100 Ohm in order to see 45 degree lag of current against voltage. Thanks a lot again.

hurz

6 years ago

@lenzrulz learned nothing and is not interessted to learn anything. Everything hes doing is splitting the community and organising conflicts. This is his lifetask. 24/7 from his basement room.

hurz

6 years ago

There is no need to split the helpful hands we have seen here. @kiani and @westelaudio. Lenny you are an impertinent charlatan. @af_mm, you made it right and said thanks to both. Lenny is only on everycircuit to organise conflicts, what an asshole

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