LTspice question

[Bill Bowden]

How do I view a waveform relative to some point other than ground
using LTspice?

For example, how do I display the waveform of one side of a LC circuit
relative to the other when neither side is grounded?

Thanks,

-Bill

 

[Phil Hobbs]

On 12/23/2011 10:24 PM, Bill Bowden wrote:

How do I view a waveform relative to some point other than ground
using LTspice?

For example, how do I display the waveform of one side of a LC circuit
relative to the other when neither side is grounded?

Thanks,

-Bill

When you set the probe on one side, don't release the mouse button.
Move the mouse to the reference side (you'll see red and black probes
just like a DVM), and then release.

Alternatively you can do it right in the waveform window, by creating a
new trace and typing in "V(4)-V(5)".

Cheers

Phil Hobbs



--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net

 

[John Larkin]

On Fri, 23 Dec 2011 23:10:12 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 12/23/2011 10:24 PM, Bill Bowden wrote:
How do I view a waveform relative to some point other than ground
using LTspice?

For example, how do I display the waveform of one side of a LC circuit
relative to the other when neither side is grounded?

Thanks,

-Bill

When you set the probe on one side, don't release the mouse button.
Move the mouse to the reference side (you'll see red and black probes
just like a DVM), and then release.

Alternatively you can do it right in the waveform window, by creating a
new trace and typing in "V(4)-V(5)".

Cheers

Phil Hobbs

Or use a VCVS as an isolation amplifier. I do that, and similar
things, to make scaled, sometimes filtered, "error" signals and such.

John

 

[Fred Abse]

On Fri, 23 Dec 2011 23:10:12 -0500, Phil Hobbs wrote:

Alternatively you can do it right in the waveform window, by creating a
new trace and typing in "V(4)-V(5)".

Or just "V(4,5)"

--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)

 

[Bill Bowden]

On Dec 23, 8:10 pm, Phil Hobbs
<pcdhSpamMeSensel...@electrooptical.net> wrote:

On 12/23/2011 10:24 PM, Bill Bowden wrote:

How do I view a waveform relative to some point other than ground
using LTspice?

For example, how do I display the waveform of one side of a LC circuit
relative to the other when neither side is grounded?

Thanks,

-Bill

When you set the probe on one side, don't release the mouse button.
Move the mouse to the reference side (you'll see red and black probes
just like a DVM), and then release.

Alternatively you can do it right in the waveform window, by creating a
new trace and typing in "V(4)-V(5)".

Cheers

Phil Hobbs

Thanks, that works well. The waveform display options are new to me. I
just figured out how to adjust the x and y limits using the manual
limits option, but I haven't investigated all the other options. My
circuits are fairly simple, so I don't need too many options.

Regards,

-Bill

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot nethttp://electrooptical.net