multivibrator simulation not oscillating

[jrs2013]

Hey!

Attached is a sample circuit that I transferred from B2Spice and have been trying out Multisim.  I've spent several hours troubleshooting but can't figure out why it won't function correctly when performing transient analysis. (I'm almost 100% this is due to user error.   )   I've got several samples of these assembled in real life with a pulse interval of around 2 secs that is 16 millliseconds long and want to experiment with some of the parameters. 

Best,

R

[_user32]

jrs2013,

The prebiased model from NXP (PDTA114EE) is supposed to have an internal R network, but I don't see this in looking at the model.   Try adding the R1=R2=10K network outside the component and see if you get any results.

Also, if that by itself doesn't work, if you have the actual snapshot of the circuit in B2SPICE that would help us analyze how it is working (maybe with the trigger points when Q1 and Q3 are supposed to turn on / turn off).

Regards,

Pat Noonan

National Instruments