sawtooth circuit modeling?

[dantimatter]

hello all,

i'd like to model a circuit that outputs a sawtooth function. there's
really two things that i'm looking for: 1) a schematic of the simplest
circuit that can produce a sawtooth output, and 2) a way to model it
with something like MATLAB or Mathematica. is anyone here familiar
with any schematic capture circuit analysis packages, particularly
ones that can generate the underlying circuit equations? what i
imagine would be ideal is if i could just plunk together a couple of
resistors, capacitors, and op-amps in a SPICE like program, then get
the equations that describe the circuit, and finally carry those
equations over to MATLAB to model how things change as i vary system
parameters. i'm at a total loss here. does anyone have any
suggestions??

many thanks,
dan

[D from BC]

On Thu, 07 Jun 2007 19:25:42 -0000, dantimatter

Post by dantimatter
hello all,
i'd like to model a circuit that outputs a sawtooth function. there's
really two things that i'm looking for: 1) a schematic of the simplest
circuit that can produce a sawtooth output, and 2) a way to model it
with something like MATLAB or Mathematica. is anyone here familiar
with any schematic capture circuit analysis packages, particularly
ones that can generate the underlying circuit equations? what i
imagine would be ideal is if i could just plunk together a couple of
resistors, capacitors, and op-amps in a SPICE like program, then get
the equations that describe the circuit, and finally carry those
equations over to MATLAB to model how things change as i vary system
parameters. i'm at a total loss here. does anyone have any
suggestions??
many thanks,
dan

SwitchercadIII from Linear Technology is a free spice program..
A triangle generator can be easily defined in the program.
ex:.pick rise and fall times..

Here's some triangle generator cct. ideas
DAC
Square wave and integrator
bidirection I source and capacitor (hysteretic oscillator)
RC circuit
Sound card
XR2206
There's some bigass chip out there that does wave synthesis (forgot
number)

D from BC

[martin]

On Thu, 07 Jun 2007 19:25:42 -0000, dantimatter

Post by dantimatter
hello all,
i'd like to model a circuit that outputs a sawtooth function. there's
really two things that i'm looking for: 1) a schematic of the simplest
circuit that can produce a sawtooth output, and 2) a way to model it
with something like MATLAB or Mathematica. is anyone here familiar
with any schematic capture circuit analysis packages, particularly
ones that can generate the underlying circuit equations? what i
imagine would be ideal is if i could just plunk together a couple of
resistors, capacitors, and op-amps in a SPICE like program, then get
the equations that describe the circuit, and finally carry those
equations over to MATLAB to model how things change as i vary system
parameters. i'm at a total loss here. does anyone have any
suggestions??
many thanks,
dan

This is one of the simplest generator
http://www.oberlin.edu/physics/catalog/demonstrations/em/neonosc.html

can't help with the matlab stuff

martin

[John Fields]

On Thu, 07 Jun 2007 22:03:40 +0200, martin

Post by D from BC
On Thu, 07 Jun 2007 19:25:42 -0000, dantimatter

Post by dantimatter
hello all,
i'd like to model a circuit that outputs a sawtooth function. there's
really two things that i'm looking for: 1) a schematic of the simplest
circuit that can produce a sawtooth output, and 2) a way to model it
with something like MATLAB or Mathematica. is anyone here familiar
with any schematic capture circuit analysis packages, particularly
ones that can generate the underlying circuit equations? what i
imagine would be ideal is if i could just plunk together a couple of
resistors, capacitors, and op-amps in a SPICE like program, then get
the equations that describe the circuit, and finally carry those
equations over to MATLAB to model how things change as i vary system
parameters. i'm at a total loss here. does anyone have any
suggestions??

---
Yes, capitalize the first word of a sentence and the personal
pronoun: 'I'.

[martin]

On Thu, 07 Jun 2007 15:21:51 -0500, John Fields

Post by John Fields
On Thu, 07 Jun 2007 22:03:40 +0200, martin

Post by D from BC
On Thu, 07 Jun 2007 19:25:42 -0000, dantimatter

Post by dantimatter
hello all,
i'd like to model a circuit that outputs a sawtooth function. there's
really two things that i'm looking for: 1) a schematic of the simplest
circuit that can produce a sawtooth output, and 2) a way to model it
with something like MATLAB or Mathematica. is anyone here familiar
with any schematic capture circuit analysis packages, particularly
ones that can generate the underlying circuit equations? what i
imagine would be ideal is if i could just plunk together a couple of
resistors, capacitors, and op-amps in a SPICE like program, then get
the equations that describe the circuit, and finally carry those
equations over to MATLAB to model how things change as i vary system
parameters. i'm at a total loss here. does anyone have any
suggestions??

---
Yes, capitalize the first word of a sentence and the personal
pronoun: 'I'.

kthxbye

[J.A. Legris]

Post by dantimatter
hello all,
i'd like to model a circuit that outputs a sawtooth function. there's
really two things that i'm looking for: 1) a schematic of the simplest
circuit that can produce a sawtooth output, and 2) a way to model it
with something like MATLAB or Mathematica. is anyone here familiar
with any schematic capture circuit analysis packages, particularly
ones that can generate the underlying circuit equations? what i
imagine would be ideal is if i could just plunk together a couple of
resistors, capacitors, and op-amps in a SPICE like program, then get
the equations that describe the circuit, and finally carry those
equations over to MATLAB to model how things change as i vary system
parameters. i'm at a total loss here. does anyone have any
suggestions??
many thanks,
dan

Google this:
matlab spice interface

Many good links will magically appear. Good luck!

--
Joe

[Don Lancaster]

Post by dantimatter
hello all,
i'd like to model a circuit that outputs a sawtooth function.

Integrate a constant current.

[Rich Grise]

does anyone have any suggestions??

Go take the course again, from the beginning, but pay attention this time.

Good Luck!
Rich

[MooseFET]

Post by dantimatter
hello all,
i'd like to model a circuit that outputs a sawtooth function. there's
really two things that i'm looking for: 1) a schematic of the simplest
circuit that can produce a sawtooth output, and 2) a way to model it
with something like MATLAB or Mathematica.

Why? LTSpice does everything needed so why bring less well suited
software into the picture?


"simplest" has many meansing. Here's a bit of ASCII art:


+V ----/\/\/---------+------+----- Output
! !
--- DEVICE
--- !
! !
GND GND

DEVICE can be a NE-2 a DIAC, an SCR, ... and etc.

Post by dantimatter
is anyone here familiar
with any schematic capture circuit analysis packages, particularly
ones that can generate the underlying circuit equations? what i
imagine would be ideal is if i could just plunk together a couple of
resistors, capacitors, and op-amps in a SPICE like program, then get
the equations that describe the circuit, and finally carry those
equations over to MATLAB to model how things change as i vary system
parameters. i'm at a total loss here. does anyone have any
suggestions??
many thanks,
dan

[dantimatter]

thanks to all for the quick responses. i'd like to use MATLAB i'm
teaching half-of-a-course on systems biology, and the laboratory
component consists of a bank of computers loaded with MATLAB and
Mathematica. the machines don't have a circuit simulator. there's a
particular biological oscillator problem that i'd like the students to
think about, but it requires some circuit modeling. if this turns out
to be too difficult to implement or not intsructive, i'll just drop
this particular problem from the class.

dan

[dantimatter]

and before 'john fields' gets all preachy, there should be a 'because'
between 'MATLAB' and 'i'm' in the second sentence, and instructive
should be spelled 'instructive'.
dan

Post by dantimatter
thanks to all for the quick responses. i'd like to use MATLAB i'm
teaching half-of-a-course on systems biology, and the laboratory
component consists of a bank of computers loaded with MATLAB and
Mathematica. the machines don't have a circuit simulator. there's a
particular biological oscillator problem that i'd like the students to
think about, but it requires some circuit modeling. if this turns out
to be too difficult to implement or not intsructive, i'll just drop
this particular problem from the class.
dan

[J.A. Legris]

Post by dantimatter
thanks to all for the quick responses. i'd like to use MATLAB i'm
teaching half-of-a-course on systems biology, and the laboratory
component consists of a bank of computers loaded with MATLAB and
Mathematica. the machines don't have a circuit simulator. there's a
particular biological oscillator problem that i'd like the students to
think about, but it requires some circuit modeling. if this turns out
to be too difficult to implement or not intsructive, i'll just drop
this particular problem from the class.
dan

I suggest that you post the actual biological problem here - you just
might get lucky.

--
Joe

[dantimatter]

Post by J.A. Legris
I suggest that you post the actual biological problem here - you just
might get lucky.

the data's not published just yet, so i'm reluctant to give out too
many details. :)

it looks like you using an op-amp integrator might do the trick for
the ramping-up, and if i can rig up a switch across the capacitor that
will quickly discharge it once the voltage has reached a certain
value, then i've got my sawtooth. so now i guess the question is: how
do i implement that switch? it's been so long since i've looked at an
electronics textbook; at least 10 years. is there a way to set up
some kind of comparator, so that when the voltage on the output of the
op-amp reaches a certain threshold, the switch is thrown and the
capacitor rapidly discharges, and then is quickly thrown again so the
ramping-up can begin all over again?

many thanks to all!

dan

[D from BC]

On Fri, 08 Jun 2007 22:23:47 -0700, dantimatter

Post by dantimatter

Post by J.A. Legris
I suggest that you post the actual biological problem here - you just
might get lucky.

the data's not published just yet, so i'm reluctant to give out too
many details. :)
it looks like you using an op-amp integrator might do the trick for
the ramping-up, and if i can rig up a switch across the capacitor that
will quickly discharge it once the voltage has reached a certain
value, then i've got my sawtooth. so now i guess the question is: how
do i implement that switch? it's been so long since i've looked at an
electronics textbook; at least 10 years. is there a way to set up
some kind of comparator, so that when the voltage on the output of the
op-amp reaches a certain threshold, the switch is thrown and the
capacitor rapidly discharges, and then is quickly thrown again so the
ramping-up can begin all over again?
many thanks to all!
dan

Constant current source + 555 timer set up for astable multivibrator
operation.
D from BC

[J.A. Legris]

Post by D from BC
On Fri, 08 Jun 2007 22:23:47 -0700, dantimatter

Post by dantimatter

Post by J.A. Legris
I suggest that you post the actual biological problem here - you just
might get lucky.

the data's not published just yet, so i'm reluctant to give out too
many details. :)
it looks like you using an op-amp integrator might do the trick for
the ramping-up, and if i can rig up a switch across the capacitor that
will quickly discharge it once the voltage has reached a certain
value, then i've got my sawtooth. so now i guess the question is: how
do i implement that switch? it's been so long since i've looked at an
electronics textbook; at least 10 years. is there a way to set up
some kind of comparator, so that when the voltage on the output of the
op-amp reaches a certain threshold, the switch is thrown and the
capacitor rapidly discharges, and then is quickly thrown again so the
ramping-up can begin all over again?
many thanks to all!
dan

Constant current source + 555 timer set up for astable multivibrator
operation.
D from BC

Ugh. 555.

Notwithstanding, Win Hill provides a circuit on p.290 of AoE, Fig.
5.35.

Here's another possibility:
http://www.interq.or.jp/japan/se-inoue/e_ckt17.htm

--
Joe

[D from BC]

On Sat, 09 Jun 2007 05:22:57 -0700, "J.A. Legris"

Post by J.A. Legris

Post by D from BC
On Fri, 08 Jun 2007 22:23:47 -0700, dantimatter

Post by dantimatter

Post by J.A. Legris
I suggest that you post the actual biological problem here - you just
might get lucky.

the data's not published just yet, so i'm reluctant to give out too
many details. :)
it looks like you using an op-amp integrator might do the trick for
the ramping-up, and if i can rig up a switch across the capacitor that
will quickly discharge it once the voltage has reached a certain
value, then i've got my sawtooth. so now i guess the question is: how
do i implement that switch? it's been so long since i've looked at an
electronics textbook; at least 10 years. is there a way to set up
some kind of comparator, so that when the voltage on the output of the
op-amp reaches a certain threshold, the switch is thrown and the
capacitor rapidly discharges, and then is quickly thrown again so the
ramping-up can begin all over again?
many thanks to all!
dan

Constant current source + 555 timer set up for astable multivibrator
operation.
D from BC

Ugh. 555.
Notwithstanding, Win Hill provides a circuit on p.290 of AoE, Fig.
5.35.
http://www.interq.or.jp/japan/se-inoue/e_ckt17.htm

Parts Count from Above Link
1 dual op amp
4 resistors
1 cap
2 diodes
Split supply??!

Parts Count for 555 sawtooth gen
1 LMC555
1 JFET
1 resistor
1 capacitor
Single supply

I don't have the AoE...is fig 5.35 the 555+ Isource cct?
I make this stuff up but later discover how old my idea is.. :)
D from BC

[J.A. Legris]

Post by D from BC
On Sat, 09 Jun 2007 05:22:57 -0700, "J.A. Legris"

Post by J.A. Legris

Post by D from BC
On Fri, 08 Jun 2007 22:23:47 -0700, dantimatter

Post by dantimatter

Post by J.A. Legris
I suggest that you post the actual biological problem here - you just
might get lucky.

the data's not published just yet, so i'm reluctant to give out too
many details. :)
it looks like you using an op-amp integrator might do the trick for
the ramping-up, and if i can rig up a switch across the capacitor that
will quickly discharge it once the voltage has reached a certain
value, then i've got my sawtooth. so now i guess the question is: how
do i implement that switch? it's been so long since i've looked at an
electronics textbook; at least 10 years. is there a way to set up
some kind of comparator, so that when the voltage on the output of the
op-amp reaches a certain threshold, the switch is thrown and the
capacitor rapidly discharges, and then is quickly thrown again so the
ramping-up can begin all over again?
many thanks to all!
dan

Constant current source + 555 timer set up for astable multivibrator
operation.
D from BC

Ugh. 555.
Notwithstanding, Win Hill provides a circuit on p.290 of AoE, Fig.
5.35.
http://www.interq.or.jp/japan/se-inoue/e_ckt17.htm

Parts Count from Above Link
1 dual op amp
4 resistors
1 cap
2 diodes
Split supply??!
Parts Count for 555 sawtooth gen
1 LMC555
1 JFET
1 resistor
1 capacitor
Single supply
I don't have the AoE...is fig 5.35 the 555+ Isource cct?
I make this stuff up but later discover how old my idea is.. :)
D from BC

Yes it is. It has more parts that yours but then again, it probably
works! I like the op-amp design because it is more symmetrical. Can
you use the 555 version to make a nice triangle or reverse sawtooth?

--
Joe

[D from BC]

On Sat, 09 Jun 2007 12:47:13 -0700, "J.A. Legris"

Post by J.A. Legris

Post by D from BC
On Sat, 09 Jun 2007 05:22:57 -0700, "J.A. Legris"

Post by J.A. Legris

Post by D from BC
On Fri, 08 Jun 2007 22:23:47 -0700, dantimatter

Post by dantimatter

Post by J.A. Legris
I suggest that you post the actual biological problem here - you just
might get lucky.

the data's not published just yet, so i'm reluctant to give out too
many details. :)
it looks like you using an op-amp integrator might do the trick for
the ramping-up, and if i can rig up a switch across the capacitor that
will quickly discharge it once the voltage has reached a certain
value, then i've got my sawtooth. so now i guess the question is: how
do i implement that switch? it's been so long since i've looked at an
electronics textbook; at least 10 years. is there a way to set up
some kind of comparator, so that when the voltage on the output of the
op-amp reaches a certain threshold, the switch is thrown and the
capacitor rapidly discharges, and then is quickly thrown again so the
ramping-up can begin all over again?
many thanks to all!
dan

Constant current source + 555 timer set up for astable multivibrator
operation.
D from BC

Ugh. 555.
Notwithstanding, Win Hill provides a circuit on p.290 of AoE, Fig.
5.35.
http://www.interq.or.jp/japan/se-inoue/e_ckt17.htm

Parts Count from Above Link
1 dual op amp
4 resistors
1 cap
2 diodes
Split supply??!
Parts Count for 555 sawtooth gen
1 LMC555
1 JFET
1 resistor
1 capacitor
Single supply
I don't have the AoE...is fig 5.35 the 555+ Isource cct?
I make this stuff up but later discover how old my idea is.. :)
D from BC

Yes it is. It has more parts that yours but then again, it probably
works! I like the op-amp design because it is more symmetrical. Can
you use the 555 version to make a nice triangle or reverse sawtooth?

It's all up to the quality of the current source in the 555 cct..
I don't know the fine bugs of a JFET I source used in this app..

Yes triangle can be formed too..The 555 would need to control a
sink/source Iregulator.

Reverse sawtooth can be done with inversion to regular sawtooth.
D from BC

[MooseFET]

Post by J.A. Legris

Post by D from BC
On Sat, 09 Jun 2007 05:22:57 -0700, "J.A. Legris"

Post by J.A. Legris

Post by D from BC
On Fri, 08 Jun 2007 22:23:47 -0700, dantimatter

Post by dantimatter

Post by J.A. Legris
I suggest that you post the actual biological problem here - you just
might get lucky.

the data's not published just yet, so i'm reluctant to give out too
many details. :)
it looks like you using an op-amp integrator might do the trick for
the ramping-up, and if i can rig up a switch across the capacitor that
will quickly discharge it once the voltage has reached a certain
value, then i've got my sawtooth. so now i guess the question is: how
do i implement that switch? it's been so long since i've looked at an
electronics textbook; at least 10 years. is there a way to set up
some kind of comparator, so that when the voltage on the output of the
op-amp reaches a certain threshold, the switch is thrown and the
capacitor rapidly discharges, and then is quickly thrown again so the
ramping-up can begin all over again?
many thanks to all!
dan

Constant current source + 555 timer set up for astable multivibrator
operation.
D from BC

Ugh. 555.
Notwithstanding, Win Hill provides a circuit on p.290 of AoE, Fig.
5.35.
http://www.interq.or.jp/japan/se-inoue/e_ckt17.htm

Parts Count from Above Link
1 dual op amp
4 resistors
1 cap
2 diodes
Split supply??!
Parts Count for 555 sawtooth gen
1 LMC555
1 JFET
1 resistor
1 capacitor
Single supply
I don't have the AoE...is fig 5.35 the 555+ Isource cct?
I make this stuff up but later discover how old my idea is.. :)
D from BC

Yes it is. It has more parts that yours but then again, it probably
works! I like the op-amp design because it is more symmetrical. Can
you use the 555 version to make a nice triangle or reverse sawtooth?

Thats easy. Doing a sine wave oscillator with an LM555 is a bit
harder.

On the CMOS LM555, the pin 3 swings all the way to either rail. A
couple of resistors with diodes in series can make any rise vs fall
ration within reason.

[Jasen]

Post by dantimatter

Post by J.A. Legris
I suggest that you post the actual biological problem here - you just
might get lucky.

the data's not published just yet, so i'm reluctant to give out too
many details. :)
it looks like you using an op-amp integrator might do the trick for
the ramping-up, and if i can rig up a switch across the capacitor that
will quickly discharge it once the voltage has reached a certain
value, then i've got my sawtooth. so now i guess the question is: how
do i implement that switch? it's been so long since i've looked at an
electronics textbook; at least 10 years. is there a way to set up
some kind of comparator, so that when the voltage on the output of the
op-amp reaches a certain threshold, the switch is thrown and the
capacitor rapidly discharges, and then is quickly thrown again so the
ramping-up can begin all over again?

depending on the voltage and current involved you could thyistor with a
zener to set the trigger level, the ne32 neon lamp, or just a spark gap,

Bye.
Jasen

[Bret Ludwig]

Post by Jasen

Post by dantimatter
it looks like you using an op-amp integrator might do the trick for
the ramping-up, and if i can rig up a switch across the capacitor that
will quickly discharge it once the voltage has reached a certain
value, then i've got my sawtooth. so now i guess the question is: how
do i implement that switch? it's been so long since i've looked at an
electronics textbook; at least 10 years. is there a way to set up
some kind of comparator, so that when the voltage on the output of the
op-amp reaches a certain threshold, the switch is thrown and the
capacitor rapidly discharges, and then is quickly thrown again so the
ramping-up can begin all over again?

depending on the voltage and current involved you could thyistor with a
zener to set the trigger level, the ne32 neon lamp, or just a spark gap,

The classic sawtooth osc used a neon lamp or as I vaguely remember
some kind of diode.

A high voltage one used the 0Z4 if you know what that was.

[Don Lancaster]

Post by MooseFET

Post by dantimatter
hello all,
i'd like to model a circuit that outputs a sawtooth function. there's
really two things that i'm looking for: 1) a schematic of the simplest
circuit that can produce a sawtooth output, and 2) a way to model it
with something like MATLAB or Mathematica.

Why? LTSpice does everything needed so why bring less well suited
software into the picture?
+V ----/\/\/---------+------+----- Output
! !
--- DEVICE
--- !
! !
GND GND
DEVICE can be a NE-2 a DIAC, an SCR, ... and etc.

Post by dantimatter
is anyone here familiar
with any schematic capture circuit analysis packages, particularly
ones that can generate the underlying circuit equations? what i
imagine would be ideal is if i could just plunk together a couple of
resistors, capacitors, and op-amps in a SPICE like program, then get
the equations that describe the circuit, and finally carry those
equations over to MATLAB to model how things change as i vary system
parameters. i'm at a total loss here. does anyone have any
suggestions??
many thanks,
dan

Your "bit of ASCII art" is only capable of generating a sawtooth
waveform with an infinite input voltage.

It instead generates an exponantial waveform.

The best way to generate a sawtooth is to integrate a constant current.

[Jasen]

Post by dantimatter
hello all,
i'd like to model a circuit that outputs a sawtooth function. there's
really two things that i'm looking for: 1) a schematic of the simplest
circuit that can produce a sawtooth output, and 2) a way to model it
with something like MATLAB or Mathematica. is anyone here familiar
with any schematic capture circuit analysis packages, particularly
ones that can generate the underlying circuit equations? what i
imagine would be ideal is if i could just plunk together a couple of
resistors, capacitors, and op-amps in a SPICE like program, then get
the equations that describe the circuit, and finally carry those
equations over to MATLAB to model how things change as i vary system
parameters. i'm at a total loss here. does anyone have any
suggestions??

a square wave fed to a R-C low-pass filter.

that's basically a logarythmic decay curve in both directions.

and similar to what you'd find on pin 2 of a 555 based astable oscilator.

Bye.
Jasen

[Winfield]

Post by dantimatter
i'd like to model a circuit that outputs a sawtooth function. there's
really two things that i'm looking for: 1) a schematic of the simplest
circuit that can produce a sawtooth output, and 2) a way to model it
with something like MATLAB or Mathematica. is anyone here familiar
with any schematic capture circuit analysis packages, particularly
ones that can generate the underlying circuit equations? what i
imagine would be ideal is if i could just plunk together a couple of
resistors, capacitors, and op-amps in a SPICE like program, then get
the equations that describe the circuit, and finally carry those
equations over to MATLAB to model how things change as i vary system
parameters. i'm at a total loss here. does anyone have any
suggestions??

You're at a total loss? Of course we'd all like a program that
would convert our randomly plunked-down "circuit" into a set of
relevant equations, but such a beast does not exist. If someone
were to write a program that would attempt to recognize common
circuits and supply all the relevant preprogrammed formulas.
That'd be nice, but it would quickly be seen as a mere toy,
only able to handle a limited set of pre-programmed circuits.
Even for those, it'd probably fail to provide a critical piece
of information that one had in mind for his exact application.

As a teacher, a better approach would be to teach your students
how to derive the formulas themselves, and how to estimate or
calculate the circuit results. Or you could have them run some
spice simulations and compare some measured results from spice
against their calculations. ON Semiconductor used to offer the
demo version of Intusoft's spice on free CDs, which you could
order and hand out to your students. You can ask, but I think
now they only offer downloads, but they're pretty big files,
https://www.onsemi.com/PowerSolutions/myon/intusoft.do Or get
all the files from Intusoft, http://www.intusoft.com/demos.htm

[dantimatter]

Post by Winfield
As a teacher, a better approach would be to teach your students
how to derive the formulas themselves, and how to estimate or
calculate the circuit results. Or you could have them run some

this is not a course in circuits, it's a course in using computers to
address biological problems. most of the students in the biological
sciences at my university have zero experience with MATLAB,
Mathematica, IDL, Perl, or any of the other tools that physicists and
engineers use to solve problems. what i was hoping for is a set of
differential equations that the kids would have to numerically solve
using one of those common computational tools. the circuit would
simply be a simple projection of the complex underlying genetic
network, something to sort of 'motivate' the problem.

dan

[John Fields]

On Sun, 10 Jun 2007 07:35:23 -0700, dantimatter

Post by dantimatter

Post by Winfield
As a teacher, a better approach would be to teach your students
how to derive the formulas themselves, and how to estimate or
calculate the circuit results. Or you could have them run some

this is not a course in circuits, it's a course in using computers to
address biological problems. most of the students in the biological
sciences at my university have zero experience with MATLAB,
Mathematica, IDL, Perl, or any of the other tools that physicists and
engineers use to solve problems. what i was hoping for is a set of
differential equations that the kids would have to numerically solve
using one of those common computational tools. the circuit would
simply be a simple projection of the complex underlying genetic
network, something to sort of 'motivate' the problem.

---
You're obviously not an ignorant person, so why do you choose to not
use the conventional rules for written English?