transformer in spice simulation problem

[andy2000a]

hspice transformer

Hi
I make a transformer simulation model

XFORMER21 N1 N2 N3 N4
VM1 N9 N7 DC 0
RS1 N3 N9 1U
E1 N7 N4 N1 N2 20
F1 N1 N2 VM1 20
RP N2 N1 1MEG

but I find I use mos switch in N2 (N1 is input Vcc) on/off
I already set N3/N4 ration= 10 * v(N1, N2)
but N3 N4 no output signal ,
because N1 N2 signal is very small
because pwr_mos Rds is small..

how to really simulation power_mos & transformer in hspice ?

 

[papyaki]

Hi,

Dont really understand your model, but F1 (F1 N1 N2 VM1 20) is controlled by VM1 which is set to DC 0 (VM1 N9 N7 DC 0) with no AC value ?

 

[andy2000a]

I find some textbook only DC , no AC value

and I find another model in

**broken link removed**

see spice transformer.html

, I don't know why use K , some circuit simulation use L+K set K-> 0.99999
but another model use behavior model which is better ?

and another problem is use L in hspice usually cause "no convergency simulation .."

I hope some designer can give me a PWM + transformer spice netlist
basic PWM like "forward "

 

[andy2000a]

l1 1 0 2000
l2 3 4 20
riso 4 0 10meg
k l1 l2 0.999999999
rs 2 1 0.1
rl 3 0 100
vin 2 0 sin(0 170 60 0 0)

.OPTIONS post=1
.op
.tran 0.01m 44m

.probe tran v(vin) v(1) v(2) v(3) i(l1) i(l2)
from L1 L2 ration is 10:1 , input 170v AC signal
but I use hspice simulation v(3) signal is very very small ..
why ??

 

[flatulent]

It looks like your transformer is not connected properly. You have the output 3 and 4 but you connect one terminal via a large resistor to ground and measure the other terminal to ground through a small value resistor. Try measuring the (3.4) terminal pair.