hi,

is it possible to simulate (plot) max. power transfered to load by changing R load in LTSpice?

 

What do you mean?

It's easy to plot the power dissipated by a load, just set the trace expression to (V(nXXXX)-V(nXXXX))*I(Load)

V(nXXXX) are the nodes at either side of the load.

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I do not answer private messages asking for help because no one else can: benefit from advice I may give or correct me if I'm wrong.

Please ask on the open forum if you have a question and I'll be happy to help, if I know the answer.

 

what i mean is that; i want to vary the value of R load and plot the power dissipated to load resistance. hence be able to see the maximum power dissipated to the load.

ok?

 

No, I don't know how to do that.

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I do not answer private messages asking for help because no one else can: benefit from advice I may give or correct me if I'm wrong.

Please ask on the open forum if you have a question and I'll be happy to help, if I know the answer.

 

hi t,
Is this what you are asking.?

Attached Thumbnails

 

Attached Files

ParaTherm1a.asc (498 Bytes, 15 views)

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Eric " Good enough is Perfect "
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hi t,
Another example.

Click RUN, place the cursor on the load resistor so that the meter icon is displayed and press the ALT key to show a thermometer icon.

Attached Thumbnails

 

Attached Files

ParaTherm1b.asc (538 Bytes, 12 views)

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Eric " Good enough is Perfect "
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Do you mean the peak power or the average power?
The peak power can be had the way Hero told you about.

If you need the average power you would integrate i(t)*e(t)
over all time, which is the same as using an RC filter on i(t)*e(t)
where the time constant is large compared to the change in
the amplitude of the waveform.

 

hi eric,
ok, i'm using PSpice now.
actually what i was thinking is this (if i'm right, ok?);

looking at the circuit below, RL (or R9) will dissipate maximum power when equals to thervenin resistance( which equals 230.8k if i'm correct).

i was expecting power to increase till R9= 230.8k then decrease afterwards.
am i right? if yes, why isn't the case here looking at the plot.

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hi t,
Please post your asc file.

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Eric " Good enough is Perfect "
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hi, eric

i think i've got it.
i've created RL as a global parameter.
isn't what i should expect?

Attached Thumbnails

 

 

hi t,
Please post your asc file, in that way I can compare your results without having to build the sim.

I would suggest that you look in spice tools menu and change the plot background colour to white , also make the plot lines wide/thick.

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Eric " Good enough is Perfect "
I will NOT answer PM's requesting technical help, please use the Forum
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hi,
i can't identify asc file in my project files. where can i find it?

 

Eric, he's using Pspice now. I suspect that's why he can't find the .ASC file.

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Ron

 

Thanks Ron for confirming that.

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Eric " Good enough is Perfect "
I will NOT answer PM's requesting technical help, please use the Forum
PIC tutorials: Nigel's www.winpicprog.co.uk/ Bill's: www.blueroomelectronics.com/