Current Sources

[Chris]

Hi all,

Under what circumstances would you use a current source in a spice
simulation as opposed to a voltage source?

thanks.

 

[Tim Wescott]

On Wed, 02 Mar 2016 23:07:14 +0000, Chris wrote:

Hi all,

Under what circumstances would you use a current source in a spice
simulation as opposed to a voltage source?

thanks.

When I need a current source.

Would you like to ask your question in a way that gets a sensible
answer? I can only guess what's going on in your head that you don't
know the answer already.

Some, but not all, reasons to use a current source:

1: You want a current that's independent of the voltage -- 0V or 100, you
need that current.

2: You're modeling a sensor or a load or some other physical process that
tends to be constant current.

3: Part of your circuit will be a current source of some sort but you
don't want to simulate that part -- so jam in a current source and be
done.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

 

[Black Iccy]

On Wed, 2 Mar 2016 23:07:14 -0000 (UTC), Chris <cbx@noreply.com> wrote:

Hi all,

Under what circumstances would you use a current source in a spice
simulation as opposed to a voltage source?

thank

Google: 'long-tailed pair' perhaps?

 

[John Larkin]

On Wed, 2 Mar 2016 23:07:14 -0000 (UTC), Chris <cbx@noreply.com>
wrote:

Hi all,

Under what circumstances would you use a current source in a spice
simulation as opposed to a voltage source?

thanks.

A controlled current source and a cap makes a nice integrator.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[George Herold]

On Wednesday, March 2, 2016 at 9:19:56 PM UTC-5, Tim Wescott wrote:

On Wed, 02 Mar 2016 23:07:14 +0000, Chris wrote:

Hi all,

Under what circumstances would you use a current source in a spice
simulation as opposed to a voltage source?

thanks.

When I need a current source.

Chris seems to ask some broad question, and then go away.
George H.

Would you like to ask your question in a way that gets a sensible
answer? I can only guess what's going on in your head that you don't
know the answer already.

Some, but not all, reasons to use a current source:

1: You want a current that's independent of the voltage -- 0V or 100, you
need that current.

2: You're modeling a sensor or a load or some other physical process that
tends to be constant current.

3: Part of your circuit will be a current source of some sort but you
don't want to simulate that part -- so jam in a current source and be
done.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

 

[Cursitor Doom]

On Thu, 03 Mar 2016 12:12:15 -0800, George Herold wrote:

Chris seems to ask some broad question, and then go away.
George H.

Homework question?

 

[szczepan bialek]

"Chris" <cbx@noreply.com> napisał w wiadomości
news:nb7rn2$n10$5@dont-email.me...

Hi all,

Under what circumstances would you use a current source in a spice
simulation as opposed to a voltage source?

"The magnet is held to prevent it from rotating, while the disc is spun on
its axis. The result is that the galvanometer registers a direct current.
The apparatus therefore acts as a generator, variously called the Faraday
generator, the Faraday disc, or the homopolar (or unipolar) generator." See:
https://en.wikipedia.org/wiki/File:Solid_Faraday_disc.PNG

Such generator has a big current but very low voltage.
S*

 

[John Larkin]

On Fri, 4 Mar 2016 18:34:31 +0100, "szczepan bialek"
<sz.bialek@wp.pl> wrote:

"Chris" <cbx@noreply.com> napisał w wiadomości
news:nb7rn2$n10$5@dont-email.me...
Hi all,

Under what circumstances would you use a current source in a spice
simulation as opposed to a voltage source?

"The magnet is held to prevent it from rotating, while the disc is spun on
its axis. The result is that the galvanometer registers a direct current.
The apparatus therefore acts as a generator, variously called the Faraday
generator, the Faraday disc, or the homopolar (or unipolar) generator." See:
https://en.wikipedia.org/wiki/File:Solid_Faraday_disc.PNG

Such generator has a big current but very low voltage.
S*

But it's hardly a current source.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics