# Simple circuit simulation using pspice/multisim

#### Dàrk Proféssor

Joined Oct 1, 2016
6
Hi guys.
I've been trying to make simulation for a circuit with a diodes and an ac source on Spice & Multisim.
Now, for some reason the current is always 0 !!!!

I've simplified the circuit and still have the same issue. The result was as follows :
FOR PSPICE :

AND ON MULTISIM :

This is transient simulation.

The current being zero seems illogical for me !
Is there something wrong with the values given? or with the simulation ?
(Pspice file is attached)

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#### WBahn

Joined Mar 31, 2012
26,398
What do you expect the peak current to be?

In the first sim the peak amplitude is about 9.7 V. You have a 3 kΩ resistor. So the peak current would be about 0.0032 A. Where would YOU plot a value of 0.0032 on that axis?

Try either scaling one of the values to something comparable to the other (say multiply the current by 1000 so that the plot is in mA instead of A) or use the second axis (most sim programs support at least two axes, one of the left and one on the right).

#### Alec_t

Joined Sep 17, 2013
11,808
I don't know what quirks Pspice and Multisim have, but with LTspice you need to probe the current in a component, not in a connecting wire.

#### WBahn

Joined Mar 31, 2012
26,398
I don't know what quirks Pspice and Multisim have, but with LTspice you need to probe the current in a component, not in a connecting wire.
It looks like he is probing the current at the anode of the diode in both cases.

#### SLK001

Joined Nov 29, 2011
1,548
Yeah, you need to scale the current to see it. In PSpice, the current probe can only be placed at junctions (where a wire connects to a part). If you have a cursor, you can view the current value as you move it.

#### Dàrk Proféssor

Joined Oct 1, 2016
6
What do you expect the peak current to be?

In the first sim the peak amplitude is about 9.7 V. You have a 3 kΩ resistor. So the peak current would be about 0.0032 A. Where would YOU plot a value of 0.0032 on that axis?

Try either scaling one of the values to something comparable to the other (say multiply the current by 1000 so that the plot is in mA instead of A) or use the second axis (most sim programs support at least two axes, one of the left and one on the right).
Thanks Man, that really helped out.
In fact, I am truly embarrassed of how trivial the issue is xD

Thank you again =)

#### WBahn

Joined Mar 31, 2012
26,398