hi everyone , im very confuse with this circuit, i need to calculate P=IV, in this circuit it shows many current and, is it correct if i took current from VDD
i understand that for using P=IV, the voltage from power supply is V=8V, and my question is it correct if i took current from VDD, or i need to add all the current from all component?

 

hi aryna,
Welcome to AAC
Please post your LTS asc file and we can run the simulation and suggest a method.
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this is the design , and also i attach the opa227 library, pls help me everyoneeee

 

hi a,
Downloaded your files.
The power supply connections don't make any sense.?
Why have you used two labels for each supply.?

I will edit and run and post back.
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hi aryna,
Before I post a solution, can you confirm this is a Homework assignment.?

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yes it is homework

 

because i just trying to made me more understand
VCC=VDD
VEE=VSS
because opa227 in VCC and VEE

 

hi aryna,
As this is Homework I can only guide you thru the problem, not give you the final answer, OK.
So could you first redraw your circuit like this image, then we can do the next step.
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okay , i already redraw it, then what should i do?

 

hi,
Add these two lines, run the sim,check the error log.
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may i ask why the voltage supply draw like that?

 

may i ask why the voltage supply draw like that?

Hi,
Just my preferred way.
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i dont know why become like this

 

hi,
I did say copy my drawing, you missed out this.
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oh sorry i missed out, and i already run it, how to check the error log.

 

hi,
Look at thsi image.
To see the Power plot.
Run the sim.
Place your cursor on the V3 symbol, press the ALT and left mouse click.
OK.?
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okay i get it, but why the value of power become negative for V3= -0.0540892, and may i ask a little bit explanation of this
.meas TRAN arg1 AVG (I(V3)*V(pv))
And why mine like this

 

so basically the power is negative because the current negative? can you explain to me why? is it correct to measure power consumption in is P = I(Vdd)*V(vdd)

 

hi,
.meas TRAN arg1 AVG (I(V3)*V(pv))

This is explained in the Help files. measure,
TRAN for analysis method
arg1 is a name for a Variable
AVG is the Average value
of I(V3) * V(pv)

How do you get a run time of 5.4 seconds .???

it should be

Your power values are much to high,,, ~ 7 Watts is wrong,

LTSpice chooses the direction of the current so it may sometimes give a negative value, for power it must be positive.

Look at this and double check.

 

idk where its wrong can you check for me pls?
so the power basically positive? even the value negative?