Need some help with simulation

[guitvinny]

Hi,

I use multisim from N.I. to simulate a class A amp, but I need a PP UL transfo 40% tap rated at 25W min for the simulation. I'm not familiar with creating new spice model, so if you can help me along the process or point me a direction or a model that would be great. Thank in advance.

I've attached the simulation so far.

[jackinnj]

I've seen this somewhere -- you'll have to use the symbol editor to create your own device -- PM me and I will send you a MSIM file with the transformer -- then you can copy it to your database.

.SUBCKT 1650R 1 2 3 4 5 6 7 8 9
* Push Pull transformer, with Ultralinear taps at 40%
* 5000 to 16 ohms, with 8 ohm and 4 ohm taps, 3db 15 to 60Khz
* Hammond 1650R
LP1 10 20 2.409088925 ; PRIMARY
LS1 20 3 1.070706189 ; primary, scrren grid tap portion
LS2 3 40 1.070706189
LP2 40 50 2.409088925
LA1 60 70 0.007348166 ; SPEAKER SECONDARY
LA2 70 80 0.003674083
LA3 90 9 0.021414124
K12 LP1 LS1 .99
K13 LP1 LS2 .99
K14 LP1 LP2 .99
K21 LP1 LA1 .99
K22 LP1 LA2 .99
K23 LP1 LA3 .99
K31 LA1 LA2 .99
K32 LA1 LA3 .99
RP1 1 10 30.0
RP2 2 20 15.0
RP3 4 40 15.0
RP4 5 50 30.0
RS1 6 60 0.1
RS2 7 70 0.1
RS3 8 80 0.1
.ENDS 1650R

[guitvinny]

Great thanks, but as I said I'm not familiar with creating a new model, how do I assing the spice model to the design ? With component wizard.. i guess.. further help would be appreciated

[jackinnj]

Open the component editor to create a new component. For the footprint on these big objects I just use a single-row header with 9 pins -- you're not going to glue it down to a PCB anyway -- but you can change the shape when you transfer to Ultiboard.

I don't think that there is a multi-tap primary and secondary template in the MSIM database, so I create a symbol which is attached below -- this only takes a few seconds.

You should take a look at the various transformer models in the database -- it will give you a cheap educational tour.

[guitvinny]

Great, I manage to get the model, but when I try to use it I got many unusual error. The .pdf is the circuit, PM me if you want the multisim file.. thanks alot...