12vrms. probe shows 10kv 500v 1.7kv wtf!!

[Arthur92710]

I have a circuit with a 12vrms ac supply. but the probe shows various voltages, not 12vrms.

[AdamB]

Hey there,

That's not really much to go on!

Can you post the circuit?  What version of MultiSim are you using?  Do you have any other parts in the circuit?

Any more information you can give us will help!

Thanks

AdamB

[Arthur92710]

ok here it is.

I am using ms 10

[lacy]

I think I may have found something that will help. Goto SIMULATE>INTERACTIVE SIMULATION SETTINGS>INTIAL CONDITIONS and in the drop down box select Set to Zero. I think this is going to give you what your looking for. Also you might want to addf a ground to your AC Input voltage source.

I hope this give you what your looking for, because this is all I could find.

Have a Nice Day

[Arthur92710]

if i set it to zero it starts at 0 and goes to 12 the more up. the probe also says 0vrms and 500mv p-p

[Arthur92710]

also is there an alternative to multisim? something that works better. all iv had with it is problems.

[lacy]

I have been re-examining your circut and have come up with something strange.  I cannot measure the AC Voltage across the source even with the Multimeter. It is connected to the bridge and all I see is DC on both sides of the Bridge Rectifier.  I know in reality this wouldn't be the case, but the bridge seem to me to be acting as a extemely low resistance in the simulator cause the AC to disappear on the source side.

This is the first time I have encountered this. Maybe AdamB or other NI team members has some explaination for this that we both could learn from.

[lacy]

I will not recommend other software on this forum. Sorry, but I feel strongly that even with it's minor problems that Multisim is still the best one out there. Once some the the little annoying problems are ironed out by NI, no one will be able to touch it.

Have A Nice Day.

[lacy]

I am still examining your circuit. One thing I noticed is that you have the RF coil tied in before the Regulator. When I measured the voltage at that point it was reading 150VDC. I then tied the RF Coil to the output of the regulator and the voltage at the input to the regulator dropped to 12.7VDC. and the waveform output at the transistor also dropped to around 10V. It may be transfering the RF frequency back to the bridge and that is being rectifed and added to the 12VDC.

I don't know if this was a problem or not, but I thought I would let you know some of my findings. I am still not able to measure the AC Voltage source and I am continuing to investigate to find out whether it is a circuit problem or a software glitch.

I will let you know of any more findings that I come across.

Have A Nice day.

[lacy]

Here's an update on my findings. I reconstructed your circuit on a diffent schematic sheet and tested it as I was wiring components into the circuit. Everything was fine as far as the power supply until I hooked the 555 Timer to it. Then at that point the AC reading disappeared, but the DC Voltage still showed close to 12VDC. Also I didn't have the scope hooked up at this time either.

I don't know what is causing the circuit to behave in this manner. I could not find a circuit error based upon these tests I performed. It has to be a software issue in my opinion.

What I did was forward this circuit to Technical Support for them to look at and maybe find a reason for this behavior. I hope they can examine it and find out a reason behind it and give us a workaround solution until it is fixed permanently.

I wish there was more I could do, but I have exhausted every idea that I have.

Have A Nice Day