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[LTSpice IV] Circuit with floating nodes on using relaysw

O

Olaf

Jan 1, 1970
0
Hi,

from the attached schematics I've got the error/warning:

WARNING: Node N005 is floating.
WARNING: Node N007 is floating.
WARNING: Node N003 is floating.
WARNING: Node N013 is floating.

....

This circuit has floating nodes.

I'm not aware on floating nodes. I assume a simple on/off switch with 2
contacts - since I use 4 of them this could produce the problem
mentioned above. Further more there are only 2 wire handles on the symbol.

Did I miss something? How to fix it?

Thanks,
Olaf

Version 4
SHEET 1 880 680
WIRE -176 -192 -176 -208
WIRE -176 -80 -176 -112
WIRE -64 -80 -176 -80
WIRE -224 -48 -320 -48
WIRE -176 -48 -176 -80
WIRE -64 -48 -64 -80
WIRE -224 -32 -224 -48
WIRE -224 32 -224 16
WIRE -224 32 -320 32
WIRE -176 48 -176 32
WIRE -64 48 -64 16
WIRE -64 48 -176 48
WIRE 48 80 48 0
WIRE 64 80 48 80
WIRE 128 80 128 0
WIRE 128 80 112 80
WIRE 320 80 320 0
WIRE 336 80 320 80
WIRE 400 80 400 0
WIRE 400 80 384 80
WIRE -176 128 -176 48
WIRE -112 128 -176 128
WIRE 32 128 -32 128
WIRE 48 128 32 128
WIRE 144 128 128 128
WIRE 192 128 144 128
WIRE 304 128 256 128
WIRE 320 128 304 128
WIRE 432 128 400 128
WIRE 496 128 432 128
WIRE -176 208 -176 128
WIRE -64 208 -176 208
WIRE -224 240 -320 240
WIRE -176 240 -176 208
WIRE -64 240 -64 208
WIRE 32 240 32 128
WIRE 48 240 32 240
WIRE 144 240 144 128
WIRE 144 240 112 240
WIRE 304 240 304 128
WIRE 336 240 304 240
WIRE 432 240 432 128
WIRE 432 240 400 240
WIRE -224 256 -224 240
WIRE -224 320 -224 304
WIRE -224 320 -320 320
WIRE -176 336 -176 320
WIRE -64 336 -64 304
WIRE -64 336 -176 336
WIRE -176 368 -176 336
WIRE -176 480 -176 448
FLAG 496 128 0
FLAG -176 -208 0
FLAG -176 480 0
SYMBOL sw 32 128 M90
SYMATTR InstName S1
SYMATTR Value ""
SYMATTR SpiceModel RELAYSW
SYMBOL sw 304 128 M90
SYMATTR InstName S2
SYMATTR Value ""
SYMATTR SpiceModel RELAYSW
SYMBOL sw -176 48 M180
SYMATTR InstName S3
SYMATTR Value ""
SYMATTR SpiceModel RELAYSW
SYMBOL sw -176 336 M180
SYMATTR InstName S4
SYMATTR Value ""
SYMATTR SpiceModel RELAYSW
SYMBOL cap 256 112 R90
WINDOW 0 0 32 VBottom 0
WINDOW 3 32 32 VTop 0
SYMATTR InstName C1
SYMATTR Value 5µ
SYMBOL ind2 -16 144 M270
WINDOW 0 32 56 VTop 0
WINDOW 3 3 57 VBottom 0
SYMATTR InstName L1
SYMATTR Value 47µ
SYMATTR Type ind
SYMBOL voltage -176 -96 R180
WINDOW 0 24 104 Left 0
WINDOW 3 24 16 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value 200
SYMBOL voltage -176 464 R180
WINDOW 0 24 104 Left 0
WINDOW 3 24 16 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V2
SYMATTR Value 20
SYMBOL diode 48 256 R270
WINDOW 0 32 32 VTop 0
WINDOW 3 0 32 VBottom 0
SYMATTR InstName D1
SYMBOL diode 336 256 R270
WINDOW 0 32 32 VTop 0
WINDOW 3 0 32 VBottom 0
SYMATTR InstName D2
SYMBOL diode -48 16 R180
WINDOW 0 24 72 Left 0
WINDOW 3 24 0 Left 0
SYMATTR InstName D3
SYMBOL diode -48 304 R180
WINDOW 0 24 72 Left 0
WINDOW 3 24 0 Left 0
SYMATTR InstName D4
SYMBOL voltage 144 0 R90
WINDOW 0 -32 56 VBottom 0
WINDOW 3 32 56 VTop 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V3
SYMATTR Value 1
SYMBOL voltage 416 0 R90
WINDOW 0 -32 56 VBottom 0
WINDOW 3 32 56 VTop 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V4
SYMATTR Value 1
SYMBOL voltage -320 -64 R0
WINDOW 3 -140 131 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V5
SYMATTR Value PULSE(0 1 0 0 0 10u 20u)
SYMBOL voltage -320 224 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V6
SYMATTR Value 0
TEXT -354 504 Left 0 !.tran 200u
TEXT -344 -264 Left 0 !.model RELAYSW SW(Ron=100m Roff=1G Vt=1 Vh=1m)
 
Q

qrk

Jan 1, 1970
0
Hi,

from the attached schematics I've got the error/warning:

WARNING: Node N005 is floating.
WARNING: Node N007 is floating.
WARNING: Node N003 is floating.
WARNING: Node N013 is floating.

...

This circuit has floating nodes.

I'm not aware on floating nodes. I assume a simple on/off switch with 2
contacts - since I use 4 of them this could produce the problem
mentioned above. Further more there are only 2 wire handles on the symbol.

Did I miss something? How to fix it?

Thanks,
Olaf

Your input terminals on the switches are floating. Grounding all the
minus input terminals of the switches will solve your floating node
issue.
 
O

Olaf

Jan 1, 1970
0
I'm not aware on floating nodes. I assume a simple on/off switch with 2
Your input terminals on the switches are floating. Grounding all the
minus input terminals of the switches will solve your floating node
issue.

Thank you! It would be interesting how to design different grounds than.

Anyway, I still have problems. I found the hint that I should label the
nets to get information about nodes which does have problems (otherwise
only the node number is shown). Is this really the only way? At this
time, I've got the error about singular matrix:

Singular matrix: Check nodes c_low and c_high
Iteration No. 6
Fatal Error: Singular matrix: check nodes c_low and c_high
Iteration No. 6

Did I miss something again?

Thanks,
Olaf




Version 4
SHEET 1 880 680
WIRE -176 -192 -176 -208
WIRE -176 -80 -176 -112
WIRE -64 -80 -176 -80
WIRE -224 -48 -320 -48
WIRE -176 -48 -176 -80
WIRE -64 -48 -64 -80
WIRE -224 -32 -224 -48
WIRE 48 0 32 0
WIRE 320 0 304 0
WIRE -320 48 -320 32
WIRE -224 48 -224 16
WIRE -176 48 -176 32
WIRE -64 48 -64 16
WIRE -64 48 -176 48
WIRE 64 80 64 64
WIRE 128 80 128 0
WIRE 128 80 112 80
WIRE 336 80 336 64
WIRE 400 80 400 0
WIRE 400 80 384 80
WIRE -176 128 -176 48
WIRE -112 128 -176 128
WIRE 32 128 -32 128
WIRE 48 128 32 128
WIRE 144 128 128 128
WIRE 160 128 144 128
WIRE 192 128 160 128
WIRE 272 128 256 128
WIRE 304 128 272 128
WIRE 320 128 304 128
WIRE 432 128 400 128
WIRE 496 128 432 128
WIRE -176 208 -176 128
WIRE -64 208 -176 208
WIRE -224 240 -320 240
WIRE -176 240 -176 208
WIRE -64 240 -64 208
WIRE 32 240 32 128
WIRE 48 240 32 240
WIRE 144 240 144 128
WIRE 144 240 112 240
WIRE 304 240 304 128
WIRE 336 240 304 240
WIRE 432 240 432 128
WIRE 432 240 400 240
WIRE -224 256 -224 240
WIRE -320 336 -320 320
WIRE -224 336 -224 304
WIRE -176 336 -176 320
WIRE -64 336 -64 304
WIRE -64 336 -176 336
WIRE -176 368 -176 336
WIRE -176 480 -176 448
FLAG 496 128 0
FLAG -176 -208 0
FLAG -176 480 0
FLAG -224 48 0
FLAG 64 64 0
FLAG 336 64 0
FLAG -224 336 0
FLAG -320 336 0
FLAG -320 48 0
FLAG 32 0 0
FLAG 304 0 0
FLAG 160 128 C_High
FLAG 272 128 C_Low
SYMBOL sw 32 128 M90
SYMATTR InstName S1
SYMATTR Value ""
SYMATTR SpiceModel RELAYSW
SYMBOL sw 304 128 M90
SYMATTR InstName S2
SYMATTR Value ""
SYMATTR SpiceModel RELAYSW
SYMBOL sw -176 48 M180
SYMATTR InstName S3
SYMATTR Value ""
SYMATTR SpiceModel RELAYSW
SYMBOL sw -176 336 M180
SYMATTR InstName S4
SYMATTR Value ""
SYMATTR SpiceModel RELAYSW
SYMBOL cap 256 112 R90
WINDOW 0 0 32 VBottom 0
WINDOW 3 32 32 VTop 0
SYMATTR InstName C1
SYMATTR Value 5µ
SYMBOL ind2 -16 144 M270
WINDOW 0 32 56 VTop 0
WINDOW 3 3 57 VBottom 0
SYMATTR InstName L1
SYMATTR Value 47µ
SYMATTR Type ind
SYMBOL voltage -176 -96 R180
WINDOW 0 24 104 Left 0
WINDOW 3 24 16 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value 200
SYMBOL voltage -176 464 R180
WINDOW 0 24 104 Left 0
WINDOW 3 24 16 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V2
SYMATTR Value 20
SYMBOL diode 48 256 R270
WINDOW 0 32 32 VTop 0
WINDOW 3 0 32 VBottom 0
SYMATTR InstName D1
SYMBOL diode 400 224 R90
WINDOW 0 0 32 VBottom 0
WINDOW 3 32 32 VTop 0
SYMATTR InstName D2
SYMBOL diode -48 16 R180
WINDOW 0 24 72 Left 0
WINDOW 3 24 0 Left 0
SYMATTR InstName D3
SYMBOL diode -48 304 R180
WINDOW 0 24 72 Left 0
WINDOW 3 24 0 Left 0
SYMATTR InstName D4
SYMBOL voltage 144 0 R90
WINDOW 0 -32 56 VBottom 0
WINDOW 3 32 56 VTop 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V3
SYMATTR Value 1
SYMBOL voltage 416 0 R90
WINDOW 0 -32 56 VBottom 0
WINDOW 3 32 56 VTop 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V4
SYMATTR Value 1
SYMBOL voltage -320 -64 R0
WINDOW 3 -140 131 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR Value PULSE(0 1 0 0 0 10u 20u)
SYMATTR InstName V5
SYMBOL voltage -320 224 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V6
SYMATTR Value 0
TEXT -352 504 Left 0 !.tran 200u
TEXT -352 536 Left 0 !.model RELAYSW SW(Ron=100m Roff=1G Vt=1 Vh=1m)
 
O

Olaf

Jan 1, 1970
0
Thank you! It would be interesting how to design different grounds than.

Anyway, I still have problems. I found the hint that I should label the
nets to get information about nodes which does have problems (otherwise
only the node number is shown). Is this really the only way? At this
time, I've got the error about singular matrix:

Singular matrix: Check nodes c_low and c_high
Iteration No. 6
Fatal Error: Singular matrix: check nodes c_low and c_high
Iteration No. 6

Did I miss something again?

yes, after changing the treshold of switches to 0.9V it works.

Greetings,
Olaf
 
O

Olaf

Jan 1, 1970
0
Now I'm really confused. I added a lossy transmission line LTRA which
results in an floating node "B". I can't get rip up of this. What's
wrong with it?

Thanks,
Olaf


Version 4
SHEET 1 948 680
WIRE -176 -192 -176 -208
WIRE -176 -80 -176 -112
WIRE -64 -80 -176 -80
WIRE -224 -48 -320 -48
WIRE -176 -48 -176 -80
WIRE -64 -48 -64 -80
WIRE -224 -32 -224 -48
WIRE 48 0 32 0
WIRE 720 0 704 0
WIRE -320 48 -320 32
WIRE -224 48 -224 16
WIRE -176 48 -176 32
WIRE -64 48 -64 16
WIRE -64 48 -176 48
WIRE 64 80 64 64
WIRE 128 80 128 0
WIRE 128 80 112 80
WIRE 736 80 736 64
WIRE 800 80 800 0
WIRE 800 80 784 80
WIRE -176 128 -176 48
WIRE -112 128 -176 128
WIRE 32 128 -32 128
WIRE 48 128 32 128
WIRE 144 128 128 128
WIRE 400 128 144 128
WIRE 704 128 432 128
WIRE 720 128 704 128
WIRE 832 128 800 128
WIRE 896 128 832 128
WIRE 400 160 400 128
WIRE 432 160 432 128
WIRE -176 208 -176 128
WIRE -64 208 -176 208
WIRE -224 240 -320 240
WIRE -176 240 -176 208
WIRE -64 240 -64 208
WIRE 32 240 32 128
WIRE 48 240 32 240
WIRE 144 240 144 128
WIRE 144 240 112 240
WIRE 704 240 704 128
WIRE 736 240 704 240
WIRE 832 240 832 128
WIRE 832 240 800 240
WIRE -224 256 -224 240
WIRE 400 288 400 256
WIRE 400 304 400 288
WIRE -320 336 -320 320
WIRE -224 336 -224 304
WIRE -176 336 -176 320
WIRE -64 336 -64 304
WIRE -64 336 -176 336
WIRE -176 368 -176 336
WIRE 400 400 400 368
WIRE 432 400 432 256
WIRE 432 400 400 400
WIRE -176 480 -176 448
FLAG 896 128 0
FLAG -176 -208 0
FLAG -176 480 0
FLAG -224 48 0
FLAG 64 64 0
FLAG 736 64 0
FLAG -224 336 0
FLAG -320 336 0
FLAG -320 48 0
FLAG 32 0 0
FLAG 704 0 0
FLAG 400 288 A
FLAG 400 400 B
SYMBOL sw 32 128 M90
SYMATTR InstName S1
SYMATTR Value ""
SYMATTR SpiceModel RELAYSW
SYMBOL sw 704 128 M90
SYMATTR InstName S2
SYMATTR Value ""
SYMATTR SpiceModel RELAYSW
SYMBOL sw -176 48 M180
SYMATTR InstName S3
SYMATTR Value ""
SYMATTR SpiceModel RELAYSW
SYMBOL sw -176 336 M180
SYMATTR InstName S4
SYMATTR Value ""
SYMATTR SpiceModel RELAYSW
SYMBOL ind2 -16 144 M270
WINDOW 0 32 56 VTop 0
WINDOW 3 3 57 VBottom 0
SYMATTR InstName L1
SYMATTR Value 47µ
SYMATTR Type ind
SYMBOL voltage -176 -96 R180
WINDOW 0 24 104 Left 0
WINDOW 3 24 16 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value 200
SYMBOL voltage -176 464 R180
WINDOW 0 24 104 Left 0
WINDOW 3 24 16 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V2
SYMATTR Value 20
SYMBOL diode 48 256 R270
WINDOW 0 32 32 VTop 0
WINDOW 3 0 32 VBottom 0
SYMATTR InstName D1
SYMBOL diode 800 224 R90
WINDOW 0 0 32 VBottom 0
WINDOW 3 32 32 VTop 0
SYMATTR InstName D2
SYMBOL diode -48 16 R180
WINDOW 0 24 72 Left 0
WINDOW 3 24 0 Left 0
SYMATTR InstName D3
SYMBOL diode -48 304 R180
WINDOW 0 24 72 Left 0
WINDOW 3 24 0 Left 0
SYMATTR InstName D4
SYMBOL voltage 144 0 R90
WINDOW 0 -32 56 VBottom 0
WINDOW 3 32 56 VTop 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V3
SYMATTR Value 1
SYMBOL voltage 816 0 R90
WINDOW 0 -32 56 VBottom 0
WINDOW 3 32 56 VTop 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V4
SYMATTR Value 1
SYMBOL voltage -320 -64 R0
WINDOW 3 -140 131 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR Value PULSE(0 1 0 0 0 10u 20u)
SYMATTR InstName V5
SYMBOL voltage -320 224 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V6
SYMATTR Value 0
SYMBOL cap 384 304 R0
WINDOW 0 -22 7 Left 0
WINDOW 3 -18 66 Left 0
SYMATTR InstName C1
SYMATTR Value 5µ
SYMBOL ltline 416 208 R90
SYMATTR InstName O1
SYMATTR Value TL
TEXT -352 504 Left 0 !.tran 200u
TEXT -352 536 Left 0 !.model RELAYSW SW(Ron=100m Roff=1G Vt=0.9 Vh=1m)
TEXT -352 568 Left 0 !.model TL LTRA(len=1.5 R=1 L=10n C=1n)
 
K

krw

Jan 1, 1970
0
Now I'm really confused. I added a lossy transmission line LTRA which
results in an floating node "B". I can't get rip up of this. What's
wrong with it?

I don't use LT Spice, but I often have to insert 1G resistors
around capacitors and inductors to get circuits to converge.
Thinking about what happens in an "ideal" world, this sort of thing
is understandable.
 
C

Charlie E.

Jan 1, 1970
0
Now I'm really confused. I added a lossy transmission line LTRA which
results in an floating node "B". I can't get rip up of this. What's
wrong with it?

Thanks,
Olaf

Olaf,
I didn't look at your circuit, but the guideline is that EVERY node
needs to have a DC path to ground. Some parts, like transformers and
transmission lines modeled via 'behavioral' modeling, don't have a
path through them for DC, so you have to have an actual ground at both
ends.

You mentioned having different grounds for different areas of the
circuit. To do this, you use a 'buffered' ground, a ground isolated
by a large resistance, such as 10MEG, or even 1G between the ground
and the circuit in question. You still have the DC path so that the
simulator can establish voltage levels, but the 'ground' level between
the two sections can now be at different levels.

For more info, look at:
http://edmondsonengineering.com/grounds.aspx


Charlie
 
K

krw

Jan 1, 1970
0
To-Email- said:
I made a symbol for PSpice...

_
-|_|

(with a "X" in the box, can't do in ASCII ;-)

easy to tack onto a schematic without taking up space... it netlists
as a 1G resistor to ground/node-zero.

That's a good idea! I'll have to figure out the best way to do it.
 
K

krw

Jan 1, 1970
0
To-Email- said:
The trick is that it's a 1-pin subcircuit... node "0" is global.

I'm pretty sure ground is global, but I'll have to test it again.
If you're using PSpice I can E-mail you the "sym" file (it's text).

Nope. Can't afford PSpice. Unfortunately, I'm stuck with @#*$&
Tina. If anyone one is looking at Tina, FORGET IT! The Freebie TI
version is alright for what it is, but the real version is next to
worthless. In fact worthless would be less aggravating.
 
Q

qrk

Jan 1, 1970
0
I'm pretty sure ground is global, but I'll have to test it again.


Nope. Can't afford PSpice. Unfortunately, I'm stuck with @#*$&
Tina. If anyone one is looking at Tina, FORGET IT! The Freebie TI
version is alright for what it is, but the real version is next to
worthless. In fact worthless would be less aggravating.
You could use LTspice. Works good, compatible with PSpice syntax, and
free. The new multithreaded capability is interesting, but I don't
have the time right now to figure out how to set it up so it's faster
than version 3 (in limited trials, limiting the number of threads to
number of processors minus 1 seemed to work best).
 
K

krw

Jan 1, 1970
0
You could use LTspice. Works good, compatible with PSpice syntax, and
free. The new multithreaded capability is interesting, but I don't
have the time right now to figure out how to set it up so it's faster
than version 3 (in limited trials, limiting the number of threads to
number of processors minus 1 seemed to work best).

I tried LTspice and still have it loaded. I didn't like it either,
though given my problems with Tina I'll likely give it a third
chance. I can't remember what my issues with it were (perhaps
libraries).
 
Q

qrk

Jan 1, 1970
0
I tried LTspice and still have it loaded. I didn't like it either,
though given my problems with Tina I'll likely give it a third
chance. I can't remember what my issues with it were (perhaps
libraries).

I find that LTspice works well. The first few versions of the new
version 4 had big problems, but Mike E. fixed them quickly. The main
thing I don't like about LTspice is the output graphing and schematic
interface. PSpice has much better graphing utility. Libraries are easy
to deal with in LTspice. Adding diodes, transistors, and opamps to
LTspice's library is easy. LT updates to the libraries maintain your
additions. Big bonus is PSpice syntax compatibility which means
quicker learning curve for me and accepting PSpice card decks.
 
K

krw

Jan 1, 1970
0
I find that LTspice works well. The first few versions of the new
version 4 had big problems, but Mike E. fixed them quickly. The main
thing I don't like about LTspice is the output graphing and schematic
interface. PSpice has much better graphing utility. Libraries are easy
to deal with in LTspice. Adding diodes, transistors, and opamps to
LTspice's library is easy. LT updates to the libraries maintain your
additions. Big bonus is PSpice syntax compatibility which means
quicker learning curve for me and accepting PSpice card decks.

Tina will accept PSpice models. Well, about as well as it does
anything. Its schematic entry is good, but the graphics I/O is
really buggy. It is impossible to get a consistent output without
tweaking a million things for every plot. I wish we could afford
PSpice, but I guess if it were my money I'd make do, too.
 
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