LtSpice something, strange happenings.

[Joerg]

I don't use Ltspice or any spice that much however, last night I pulled
something out of my old sketch books and plotted it to LTspice, with a
little change with values to be used for a specific task.

I noticed something strange. As you hover over the nodes, it is
convenient to look at the lower left corner to get information about
that node. Things like voltage, current etc. However, with a specific
drawing(this one), it is showing some off the wall or should I say off
the map, readings in measuring units that are wrong and symbols that
have no meaning for the scale unit.

Not only that, the value that is displayed down there is not even
related to what is at the node but dig this, when
I double click on any of those nodes to show it in the graph above, the
graph is correct, but the bottom view is still wrong, grossly wrong.

Tonight, I popped in a simple drawing ect, it's fine.. But reloaded
this one particular drawing, and it's all over the map down
below?

There must be something in there that is confusing the hell out of
LTSpice?

I have version 4.15s if that helps..

it's not that much of a big deal, I do most of my stuff by hand and a
few other little programs I have lying around here. Just thought I'd
ask to see if any one else has noticed this?

Did you see a submarine plow up the Guadalupe River, with a Chinese
flag? So maybe ...

Just kidding. If it's any comfort, the voltages shown down there may not
mean much. I am doing sims right now and when I hold the cursor to a
node at the top of a 3.3V DC source the text down there reads zero
volts. Of course it isn't real, in the display window later it shows
correctly.

 

[Jamie]

I don't use Ltspice or any spice that much however, last night I pulled
something out of my old sketch books and plotted it to LTspice, with a
little change with values to be used for a specific task.

I noticed something strange. As you hover over the nodes, it is
convenient to look at the lower left corner to get information about
that node. Things like voltage, current etc. However, with a specific
drawing(this one), it is showing some off the wall or should I say off
the map, readings in measuring units that are wrong and symbols that
have no meaning for the scale unit.

Not only that, the value that is displayed down there is not even
related to what is at the node but dig this, when
I double click on any of those nodes to show it in the graph above, the
graph is correct, but the bottom view is still wrong, grossly wrong.

Tonight, I popped in a simple drawing ect, it's fine.. But reloaded
this one particular drawing, and it's all over the map down
below?

There must be something in there that is confusing the hell out of
LTSpice?

I have version 4.15s if that helps..

it's not that much of a big deal, I do most of my stuff by hand and a
few other little programs I have lying around here. Just thought I'd
ask to see if any one else has noticed this?

Jamie

 

[Joerg]

Yeah, I just found out why it does that, if you start the sim at 0 DC
volts, the below display is showing you the initial values. THose could
be all over the place. I guess if you want to know that information it
could be useful

I never used an emulator before. My youngest while in trade school used
Workbench and I didn't really think much of that. When he entered JW for
Electronic Engineering they used something but it sure wasn't LtSpice,
it could of been some other spice program, I don't know.

What's JW? Not familiar with that but most of my education was overseas.

All I know is, when he'd come on for the weekends, I'd end up helping
him with homework and getting some lab builds to work correctly..

Nothing better than father and son working together on a project. As
long as there's a nice cold brewsky afterwards once it all works

First time my dad did that with me was early highschool. The oil furnace
did its telltale whoopah .. whoopah .. *POOF* and dad said "Son, I'll be
off on a biz trip soon so let's go into the dungeon, time for you to
learn how to fix that monster".

 

[Jamie]

Did you see a submarine plow up the Guadalupe River, with a Chinese
flag? So maybe ...

Just kidding. If it's any comfort, the voltages shown down there may not
mean much. I am doing sims right now and when I hold the cursor to a
node at the top of a 3.3V DC source the text down there reads zero
volts. Of course it isn't real, in the display window later it shows
correctly.

Yeah, I just found out why it does that, if you start the sim at 0 DC
volts, the below display is showing you the initial values. THose could
be all over the place. I guess if you want to know that information it
could be useful

I never used an emulator before. My youngest while in trade school used
Workbench and I didn't really think much of that. When he entered JW for
Electronic Engineering they used something but it sure wasn't LtSpice,
it could of been some other spice program, I don't know.

All I know is, when he'd come on for the weekends, I'd end up helping
him with homework and getting some lab builds to work correctly..

Jamie

 

[Robert Macy]

What's JW? Not familiar with that but most of my education was overseas.


Nothing better than father and son working together on a project. As
long as there's a nice cold brewsky afterwards once it all works

First time my dad did that with me was early highschool. The oil furnace
did its telltale whoopah .. whoopah .. *POOF* and dad said "Son, I'll be
off on a biz trip soon so let's go into the dungeon, time for you to
learn how to fix that monster".

shades of "A Christmas Story" and Darren McGavin's character as the
famous 'furnace fighter'

 

[Helmut Sennewald]

I don't use Ltspice or any spice that much however, last night I pulled
something out of my old sketch books and plotted it to LTspice, with a
little change with values to be used for a specific task.

I noticed something strange. As you hover over the nodes, it is convenient
to look at the lower left corner to get information about
that node. Things like voltage, current etc. However, with a specific
drawing(this one), it is showing some off the wall or should I say off the
map, readings in measuring units that are wrong and symbols that have no
meaning for the scale unit.

Not only that, the value that is displayed down there is not even
related to what is at the node but dig this, when
I double click on any of those nodes to show it in the graph above, the
graph is correct, but the bottom view is still wrong, grossly wrong.

Tonight, I popped in a simple drawing ect, it's fine.. But reloaded this
one particular drawing, and it's all over the map down
below?

There must be something in there that is confusing the hell out of
LTSpice?

I have version 4.15s if that helps..

it's not that much of a big deal, I do most of my stuff by hand and a few
other little programs I have lying around here. Just thought I'd
ask to see if any one else has noticed this?

Jamie

Hello Jamie,

LTspice shows the DC-operating point in the left lower corner.
This value will be calculated at the beginning before the circuit will be
simulated over time.

Best regards,
Helmut

 

[Jamie]

Hello Jamie,

LTspice shows the DC-operating point in the left lower corner.
This value will be calculated at the beginning before the circuit will be
simulated over time.

Best regards,
Helmut

yeah, I found that out. I don't use it that much.

I would bet there is a cursor/marker I can set on the sim to show me
where at what point to show the values. Clicking on the nodes are find
for value, I some times find it just simpler to look at the values as
mouse over the nodes.

Thanks.
Jamie