Help with first build....

I have built this circuit, but I am having trouble getting correct reading. I need help with the node placement as well as making sure that the parameters are set correctly. Should have a 3V rms. The goal to to be able to measure at the V at the R.

by Jhanson19
November 10, 2013

@Jhanson19,

You havea couple of simple to fix errors in your circuit.

i) the line through the inductor, L1, gives away the fact that you have shorted it out. That line is a wire straight across the inductor.

Select L1 (so it highlights red) and the shorting wire will automatically be deleted.

ii) you also have a number of (harmless) duplicated wire runs. The clue to these is the prescence of wire join dots at odd places in the wires such as at corners and at xomponent pins where there is only one wire going to the pin. A joining dot is a sure sign that there are more than 2 wires - or 1 wire and a pin - joining.

iii) part of the same problem of duplicated wire runs, there's a wire dangling inside the triangle of the ground symbol.

iv) be aware that the amplitude value of signal sources in CL (and in spice) are peak to peak values and not RMS.

If you need a sinusoidal source of 3Vrms then you can enter the amplitude as:

3*sqrt(2)

which will give you a 3V rms (4.25V pk-pk) signal.

Remember that the simple sqrt(2) scaling factor only applies to sinusoids. You can Wiki other rms scaling factors for square, triangle and sawtooth waveforms.

"The goal to to be able to measure at the V at the R."

Measure what? Voltage? Current? Bananas?

Note also that in CL(and spice), voltage sources are ideal: zero source resistance, infinite current capability.

So, C1 has no effect on the circuit. You can measure the current through it but it has no effect on the voltage across it and hence to the rest of the circuit.

:)

by signality
November 11, 2013

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