LTSpice multiwinding transformer

B

Bill Sloman

Guest
I'm trying to model a six-winding transformer - three sets of centre-tapped
coils, one pair with 0.25mH of inductance in each col, the next with 22.5uH
and the last with 2.5uH. Coil coupling is set by

K1 L1 L2 L3 L4 L5 L6 0.99

With four winding everything seems to work, but with six, neither pair of
secondaries shows any induced voltage.

Is this a known bug?

--
Bill Sloman, Nijmegen
 
Bill Sloman wrote:
I'm trying to model a six-winding transformer - three sets of centre-tapped
coils, one pair with 0.25mH of inductance in each col, the next with 22.5uH
and the last with 2.5uH. Coil coupling is set by

K1 L1 L2 L3 L4 L5 L6 0.99

With four winding everything seems to work, but with six, neither pair of
secondaries shows any induced voltage.

Is this a known bug?
Click to expand...
I don't know if it is a bug, but you could try substituting the
alternate and equivalent expression, listing the 15 mutual inductances
separately:

K12 L1 L2 0.99
K13 L1 L3 0.99
K14 L1 L4 0.99
K15 L1 L5 0.99
K16 L1 L6 0.99
K23 L2 L3 0.99
K24 L2 L4 0.99
K25 L2 L5 0.99
K26 L2 L6 0.99
K34 L3 L4 0.99
K35 L3 L5 0.99
K36 L3 L6 0.99
K45 L4 L5 0.99
K46 L4 L6 0.99
K56 L5 L6 0.99

--
NOTE: to reply, remove all punctuation from email name field

Ned Forrester n_f_orrester@whoi.edu 508-289-2226
Applied Ocean Physics and Engineering Dept.
Oceanographic Systems Lab http://adcp.whoi.edu/
Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
 
"Bill Sloman" <bill.sloman@ieee.org> schrieb im Newsbeitrag
news:4a2da0aa$0$1639$703f8584@textnews.kpn.nl...
I'm trying to model a six-winding transformer - three sets of
centre-tapped coils, one pair with 0.25mH of inductance in each col, the
next with 22.5uH and the last with 2.5uH. Coil coupling is set by

K1 L1 L2 L3 L4 L5 L6 0.99

With four winding everything seems to work, but with six, neither pair of
secondaries shows any induced voltage.

Is this a known bug?

--
Bill Sloman, Nijmegen
Click to expand...
Hello Bill,

I wonder what you did. It works like promised.
I have attached a working example with exactly your values.

You can send me your circuit for a check, if you can't find the mistake in
your circuit.

Best regards,
Helmut

Version 4
SHEET 1 880 680
WIRE -32 64 -112 64
WIRE 112 64 48 64
WIRE -112 80 -112 64
WIRE 112 96 112 64
WIRE 272 96 272 64
WIRE 432 96 432 64
WIRE -112 192 -112 160
WIRE 112 192 112 176
WIRE 112 192 -112 192
WIRE 272 192 272 176
WIRE 272 192 112 192
WIRE 432 192 432 176
WIRE 432 192 272 192
WIRE -112 208 -112 192
WIRE 112 208 112 192
WIRE 272 208 272 192
WIRE 432 208 432 192
WIRE 112 320 112 288
WIRE 272 320 272 288
WIRE 432 320 432 288
FLAG -112 208 0
SYMBOL ind2 96 80 R0
SYMATTR InstName L1
SYMATTR Value 250ľ
SYMATTR Type ind
SYMBOL ind2 96 192 R0
SYMATTR InstName L2
SYMATTR Value 250ľ
SYMATTR Type ind
SYMBOL ind2 256 80 R0
SYMATTR InstName L3
SYMATTR Value 25ľ
SYMATTR Type ind
SYMBOL ind2 256 192 R0
SYMATTR InstName L4
SYMATTR Value 25ľ
SYMATTR Type ind
SYMBOL ind2 416 80 R0
SYMATTR InstName L5
SYMATTR Value 2.5ľ
SYMATTR Type ind
SYMBOL ind2 416 192 R0
SYMATTR InstName L6
SYMATTR Value 2.5ľ
SYMATTR Type ind
SYMBOL voltage -112 64 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value SINE(0 10 20k)
SYMBOL res -48 80 R270
WINDOW 0 32 56 VTop 0
WINDOW 3 0 56 VBottom 0
SYMATTR InstName R1
SYMATTR Value 1
TEXT -120 -24 Left 0 !.tran 1m
TEXT 32 -24 Left 0 !K1 L1 L2 L3 L4 L5 L6 0.99
 
"Helmut Sennewald" <helmutsennewald@t-online.de> schreef in bericht
news:h0m9qr$ott$02$1@news.t-online.com...
"Bill Sloman" <bill.sloman@ieee.org> schrieb im Newsbeitrag
news:4a2da0aa$0$1639$703f8584@textnews.kpn.nl...
I'm trying to model a six-winding transformer - three sets of
centre-tapped coils, one pair with 0.25mH of inductance in each col, the
next with 22.5uH and the last with 2.5uH. Coil coupling is set by

K1 L1 L2 L3 L4 L5 L6 0.99

With four winding everything seems to work, but with six, neither pair of
secondaries shows any induced voltage.

Is this a known bug?

--
Bill Sloman, Nijmegen

Hello Bill,

I wonder what you did. It works like promised.
I have attached a working example with exactly your values.

You can send me your circuit for a check, if you can't find the mistake in
your circuit.
Click to expand...
Your circuit runs exactly as it should on my computer.

When I compared .asc files, the only difference I could see was that you'd
used 25ľ where I'd typed 0.000025, but switching didn't make any difference.

I've got your 2003 e-mail address and I'll send you my .asc file; it's too
long to post here and since I hope to be able to publish it in a scholarly
journal eventually, I don't really want to post it to an open forum.

--
Bill Sloman, Nijmegen
 
"Ned Forrester" <n_f_orrester@whoi.edu> schreef in bericht
news:4A2E83BD.4090505@whoi.edu...
Bill Sloman wrote:
I'm trying to model a six-winding transformer - three sets of
centre-tapped
coils, one pair with 0.25mH of inductance in each col, the next with
22.5uH
and the last with 2.5uH. Coil coupling is set by

K1 L1 L2 L3 L4 L5 L6 0.99

With four winding everything seems to work, but with six, neither pair of
secondaries shows any induced voltage.

Is this a known bug?

I don't know if it is a bug, but you could try substituting the
alternate and equivalent expression, listing the 15 mutual inductances
separately:

K12 L1 L2 0.99
K13 L1 L3 0.99
K14 L1 L4 0.99
K15 L1 L5 0.99
K16 L1 L6 0.99
K23 L2 L3 0.99
K24 L2 L4 0.99
K25 L2 L5 0.99
K26 L2 L6 0.99
K34 L3 L4 0.99
K35 L3 L5 0.99
K36 L3 L6 0.99
K45 L4 L5 0.99
K46 L4 L6 0.99
K56 L5 L6 0.99
Click to expand...
Thanks for the suggestion. In fact I'd originally listed all fifteen mutual
inductances, and only found - and tried - the more compact expression after
I'd been reduced to RTFM.

I'm obviously doing something stupid - because Helmut's test circuit works
fine - but I can't for the life of me see what it might be. I hope Helmut
can find something. in my .asc file.

--
Bill Sloman, Nijmegen
 
"Bill Sloman" <bill.sloman@ieee.org> schreef in bericht
news:4a2da0aa$0$1639$703f8584@textnews.kpn.nl...
I'm trying to model a six-winding transformer - three sets of
centre-tapped coils, one pair with 0.25mH of inductance in each col, the
next with 22.5uH and the last with 2.5uH. Coil coupling is set by

K1 L1 L2 L3 L4 L5 L6 0.99

With four winding everything seems to work, but with six, neither pair of
secondaries shows any induced voltage.

Is this a known bug?
Click to expand...
The bug was pure stupidity on my part - I typed in the Spice directive as
text (in blue) rather than as a Spice directive (which would have shown up
as black type) .

Helmut Sennewald very generously found the fault in my .asc file, and I'm
appropriately grateful.

--
Bill Sloman, Nijmegen
 
You must log in or register to reply here.

Welcome to EDABoard.com

Sponsor

Back
Top