Multisim Circuit

[ElectronicPotatoe]

Hi guys, not sure if this is the right place to post, but here it is:

I built this circuit, and when I run it I get an error.

The error only occurs when the S1 is open. If I close it, no error. Anyone knows what it could be? The troubleshooter can't find the problem. The position of the other keys must be:

S1 open
S2 Leading to the second 9V battery.
S3 closed

Thanks!

 

[Audioguru]

Maybe Multisim does not like to see battery V3, R3 and LED3 shorted by S1 and the parts to the right of S3 that are doing nothing. Remove the useless parts.

 

[ElectronicPotatoe]

Maybe Multisim does not like to see battery V3, R3 and LED3 shorted by S1 and the parts to the right of S3 that are doing nothing. Remove the useless parts.

Yeah they are not really useless. It's part of a work for college, in which we have to "prove" that LED3 would not turn on in this situation, so i really can't remove it. Thanks for the reply!

 

[RLP123123]

Yeah they are not really useless. It's part of a work for college, in which we have to "prove" that LED3 would not turn on in this situation, so i really can't remove it. Thanks for the reply!

Just saw this thread. Msim can be flaky. You may try rebuilding the ckt in a new session. There is no reason for an error with this ckt. You can prove that either LED3 may or may not be on. Depends. Did you look at the LEDs? You can set their turn on current. If a default of 5 or 10 mA is used, then of course won't turn on. If you change that to 1mA for the LEDs, then they do turn on with the S1 open. It's up to you...

 

[ElectronicPotatoe]

Just saw this thread. Msim can be flaky. You may try rebuilding the ckt in a new session. There is no reason for an error with this ckt. You can prove that either LED3 may or may not be on. Depends. Did you look at the LEDs? You can set their turn on current. If a default of 5 or 10 mA is used, then of course won't turn on. If you change that to 1mA for the LEDs, then they do turn on with the S1 open. It's up to you...

In theory LED2 would not turn on with S1 open and S2 going to the second 9V battery because the voltage drop in LED2 and R2 is too much, and the voltage would be negative, so current should flow from + to - in V2, except it can't bacause of the diode. So no matter the current I set for the LEDs to be on, it wouldn't turn on, because it's reverse biased.

By the way, Multisim is kind of weird. I rebuilt the circuit without the meters and it works. Pretty strange. Thanks!

 

[RLP123123]

In theory LED2 would not turn on with S1 open and S2 going to the second 9V battery because the voltage drop in LED2 and R2 is too much, and the voltage would be negative, so current should flow from + to - in V2, except it can't bacause of the diode. So no matter the current I set for the LEDs to be on, it wouldn't turn on, because it's reverse biased.

By the way, Multisim is kind of weird. I rebuilt the circuit without the meters and it works. Pretty strange. Thanks!

Cool. I guess I misread your statement. I thought LED3 was the question, not LED2. Wasn't certain what was meant by the second battery since there are 3 batteries in the circuit. Calling out V3 would have given more clarity.

 

[ElectronicPotatoe]

Cool. I guess I misread your statement. I thought LED3 was the question, not LED2. Wasn't certain what was meant by the second battery since there are 3 batteries in the circuit. Calling out V3 would have given more clarity.

Yes I should have said "connected to V3". My bad. Thanks!