Electrical circuit Analysis

[electronicsLearner77]

I am trying to understand the below circuit

My analysis of the circuit is since 5V is connected to both ends of the circuit there will be no current flow. Is it correct? Anything more i can understand from this circuit, this circuit is created by me to analyze different ways.

 

[danadak]

My analysis of the circuit is since 5V is connected to both ends of the circuit there will be no current flow. Is it correct?

No, the transient source, V2, is not constantly at 5V


Regards, Dana.

 

[crutschow]

the transient source, V2, is not constantly at 5V

There is a transient analysis specified, but both V1 and V2 are shown as being a constant +5V.

 

[crutschow]

My analysis of the circuit is since 5V is connected to both ends of the circuit there will be no current flow. Is it correct?

Yes.
Did you do the simulation to check?

 

[electronicsLearner77]

I get 0 Amp.
Is it that i shall not do transient analysis for constant voltage supplies?

 

[electronicsLearner77]

Can I assume this also as 0 amp current since it is in fA? I don't understand the behavior.

 

[crutschow]

I get 0 Amp.
Is it that i shall not do transient analysis for constant voltage supplies?

Yes, you can do transient analysis with constant voltage supplies.
Why would you expect other than 0 amps?

Can I assume this also as 0 amp current since it is in fA?

Yes, that value is approaching the precision of the Spice calculations.

I don't understand the behavior.

What don't you understand?
With zero voltage across the components (the same signal from both sources) you get essentially zero current, as would be expected.
If you want to see some significant current, then make one source a DC voltage.

 

[electronicsLearner77]

What don't you understand?
With zero voltage across the components (the same signal from both sources) you get essentially zero current, as would be expected.
If you want to see some significant current, then make one source a DC voltage.

Since the current seem to be fluctuating increasing and decreasing instead of a straight line.

If you want to see some significant current, then make one source a DC voltage.

Yes i am trying that i will show.

 

[electronicsLearner77]

I have applied inverted PWM's, now the current amplitude is bigger.

 

[crutschow]

Since the current seem to be fluctuating increasing and decreasing instead of a straight line.

But that's a very tiny current, likely to the limits of the computing precision in the simulator.
No matter how many digits the current is computed too, it may never be exactly zero.

 

[crutschow]

I have applied inverted PWM's, now the current amplitude is bigger.

So are you happy with those results?

 

[electronicsLearner77]

So are you happy with those results?

This is how i solved using the LR circuit the equation i get is


Are these calculations correct? But after long time the current will be 0? How is it possible?

 

[Harald Kapp]

Your calculations are good in the first part (0 ms -> 1 ms).

In the second part (1 ms -> 2 ms), however, you ignore the term (v1-v2)/r and use the result from part 1 to calculate a decaying current. What is your reasoning for doing so?

Consider instead [math] i(t) = \frac{(v_1 - v_2)}{R} \times (1 - e^{(-\frac{t}{\tau})})[/math] for [math] t \rightarrow \infty[/math]

 

[electronicsLearner77]

Your calculations are good in the first part (0 ms -> 1 ms).

In the second part (1 ms -> 2 ms), however, you ignore the term (v1-v2)/r and use the result from part 1 to calculate a decaying current. What is your reasoning for doing so?

Consider instead [math] i(t) = \frac{(v_1 - v_2)}{R} \times (1 - e^{(-\frac{t}{\tau})})[/math] for [math] t \rightarrow \infty[/math]

The circuit i have drawn and the results i am getting are completely mismatch, i think the circuit is wrong or the spice is not doing the simulations properly.

 

[Harald Kapp]

or the spice is not doing the simulations properly.

I suggest you look at your own calculations first before blaming it on SPICE.