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LTspice question

Started by Bill Bowden December 23, 2011
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
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
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
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)
On Dec 23, 8:10=A0pm, 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