Simulating SPST and SPDT switches?

[Terry Pinnell]

I've spent a few hours over the last couple of days trying to design a
realistic and easy-to-handle simulation for break-before-make toggle
switches. But I imagine this is re-inventing the wheel, as there must
be well-established techniques. I'm using Circuitmaker, but I assume
the principles must be similar in other programs.

My approach so far (to the more complex case of a SPDT switch) has
been to use two VCSs, a triangle wave input (inverted before applying
to the 2nd VCS), and altering the respective VCS's Threshold values to
get the 'break-before-make' delay. But I expect I'm making heavy
weather of it, and would be grateful for shared techniques please.

--
Terry Pinnell
Hobbyist, West Sussex, UK

 

[Jim Thompson]

On Mon, 19 Sep 2005 09:07:21 +0100, Terry Pinnell
<terrypinDELETE@THESEdial.pipex.com> wrote:

I've spent a few hours over the last couple of days trying to design a
realistic and easy-to-handle simulation for break-before-make toggle
switches. But I imagine this is re-inventing the wheel, as there must
be well-established techniques. I'm using Circuitmaker, but I assume
the principles must be similar in other programs.

My approach so far (to the more complex case of a SPDT switch) has
been to use two VCSs, a triangle wave input (inverted before applying
to the 2nd VCS), and altering the respective VCS's Threshold values to
get the 'break-before-make' delay. But I expect I'm making heavy
weather of it, and would be grateful for shared techniques please.

That's about the only way to attack it.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[Terry Pinnell]

Terry Pinnell <terrypinDELETE@THESEdial.pipex.com> wrote:

I've spent a few hours over the last couple of days trying to design a
realistic and easy-to-handle simulation for break-before-make toggle
switches. But I imagine this is re-inventing the wheel, as there must
be well-established techniques. I'm using Circuitmaker, but I assume
the principles must be similar in other programs.

My approach so far (to the more complex case of a SPDT switch) has
been to use two VCSs, a triangle wave input (inverted before applying
to the 2nd VCS), and altering the respective VCS's Threshold values to
get the 'break-before-make' delay. But I expect I'm making heavy
weather of it, and would be grateful for shared techniques please.

As I suspected, once I started thinking straight, this turned out to
be pretty simple. For a SPDT, with about 40 ms between break and make,
I'm using this arrangement:
http://www.terrypin.dial.pipex.com/Images/SPDT-Sim.gif

Anyone have any suggested alternatives please?

--
Terry Pinnell
Hobbyist, West Sussex, UK

 

[Terry Pinnell]

Jim Thompson <thegreatone@example.com> wrote:

On Mon, 19 Sep 2005 09:07:21 +0100, Terry Pinnell
terrypinDELETE@THESEdial.pipex.com> wrote:

I've spent a few hours over the last couple of days trying to design a
realistic and easy-to-handle simulation for break-before-make toggle
switches. But I imagine this is re-inventing the wheel, as there must
be well-established techniques. I'm using Circuitmaker, but I assume
the principles must be similar in other programs.

My approach so far (to the more complex case of a SPDT switch) has
been to use two VCSs, a triangle wave input (inverted before applying
to the 2nd VCS), and altering the respective VCS's Threshold values to
get the 'break-before-make' delay. But I expect I'm making heavy
weather of it, and would be grateful for shared techniques please.

That's about the only way to attack it.

...Jim Thompson

Thanks. See also my later reply. Does that design look OK?

--
Terry Pinnell
Hobbyist, West Sussex, UK