Circuit Modeling with SPICE

2 09 2011

Last week Raymond Rogers made a SPICE model of my coil circuit. Extremely helpful and awesome, thanks Ray!

SPICE is a general-purpose open source analog electronic circuit simulator.

I’ve been trying to get started with SPICE for a while now, but the steep learning curve prevented much progress. So to have a working example of a circuit I’m familiar with is so very useful.

Now we can run virtual experiment on the coil circuit and see how much current we get. Pretty damn cool!

Here are some example input values and resulting current graph:

Capacitance: 15 mF, 450V

Coil resistance: 180 mΩ

Coil inductance: 0.1mH

In this diagram the vertical axis is the voltage of a 1mΩ ammeter resistor, so 1V = 1KA.

I encourage anyone who knows splice to run this code, make changes and share results.

Also a shout out to jstults for his python script for inductance modeling.

THIS IS OPEN SOURCE SCIENCE.

Actions

Information

Date : September 2, 2011
Categories : Community, Open Source, Software, Sydney Experiment

7 responses

2 09 2011

jstults (19:07:34) :

Thanks for the nod; I’ve been meaning to get better at spice too; running your circuit is a good excuse.

I’ve also been playing a bit with QUCS; which, while still developing, has some neat capabilities and is open source.

3 09 2011

e (07:12:42) :

Coding spice by hand? o_O Just use a simulator like Tina-TI. http://focus.ti.com/general/docs/gencontent.tsp?contentId=114702&litId=sloc241a

For something simple like this, you can use http://www.falstad.com/circuit/, which is nice to use and lets you probe any point in the circuit. Is this your circuit?

http://www.falstad.com/circuit/#%24+1+5.0E-6+3.5993318835628396+41+5.0+50g+304+240+304+256+0R+224+128+192+128+0+0+40.0+450.0+0.0+0.0+0.5r+224+128+304+128+0+1000.0c+304+128+304+240+0+0.015+0.6645214101754234r+304+128+368+128+0+0.1159+368+128+432+128+0+0.1+1000000.0L+400+144+400+176+0+0+false+5.0+0.0l+464+192+464+256+0+1.0E-4+1.5943681117569497E-5r+464+256+464+320+0+0.0010g+464+320+464+336+0r+464+192+464+128+0+0.18w+432+128+464+128+0o+3+64+0+35+2.5+3.2+0+-1o+8+64+0+35+0.0048828125+3.2+1+-1

This version is easier to work with, if not 100% true-to-life:

http://www.falstad.com/circuit/#%24+1+5.0E-6+3.5993318835628396+41+5.0+50g+272+240+272+256+0R+112+128+80+128+0+0+40.0+450.0+0.0+0.0+0.5r+112+128+192+128+0+0.1c+272+128+272+240+0+0.015+7.303470967737259r+272+128+336+128+0+0.1159+336+128+400+128+0+0.1+1000000.0L+368+144+368+176+0+1+false+5.0+0.0l+432+192+432+256+0+1.0E-4+20.14111489125466r+432+256+432+320+0+0.0010g+432+320+432+336+0r+432+192+432+128+0+0.18w+400+128+432+128+0s+192+128+272+128+0+1+truex+447+195+476+200+0+20+coilx+461+296+581+301+0+20+current-sensex+281+103+332+108+0+20+wiringo+3+64+0+35+640.0+6553.6+0+-1o+7+64+0+33+320.0+1638.4+1+-1o+8+64+0+34+1.25+819.2+2+-1

3 09 2011

Mark Suppes (12:56:08) :

When I try the circuits you made, I just see a black applet window.

However the falstad example circuits are amazing!

3 09 2011

e (20:00:38) :

ooooops. some characters got stripped or something.

Direct links to simulations:

view raw

readme.md

hosted with ❤ by GitHub

	$ 1 5.0E-6 3.5993318835628396 41 5.0 50
	g 240 240 240 256 0
	R 80 128 48 128 0 0 40.0 450.0 0.0 0.0 0.5
	r 80 128 160 128 0 0.1
	c 240 128 240 240 0 0.015 0.0017903664661923875
	r 240 128 304 128 0 0.1
	159 304 128 368 128 0 0.1 1000000.0
	L 336 144 336 176 0 1 false 5.0 0.0
	l 400 192 400 256 0 1.0E-4 0.004937375236010898
	r 400 256 400 320 0 0.0010
	g 400 320 400 336 0
	r 400 192 400 128 0 0.18
	w 368 128 400 128 0
	s 160 128 240 128 0 1 true
	x 248 102 289 106 0 16 wiring
	x 416 194 440 198 0 16 coil
	x 433 293 527 297 0 16 current-sense
	o 3 64 0 35 80.0 204.8 0 -1
	o 8 64 0 34 0.3125 25.6 1 -1
	o 7 64 0 33 0.3125 204.8 2 -1

view raw

Faster.falstad.txt

hosted with ❤ by GitHub

	$ 1 5.0E-6 16.817414165184545 41 5.0 50
	g 288 240 288 256 0
	R 208 128 176 128 0 0 40.0 450.0 0.0 0.0 0.5
	r 208 128 288 128 0 1000.0
	c 288 128 288 240 0 0.015 1.4975251988401852
	r 288 128 352 128 0 0.1
	159 352 128 416 128 0 0.1 1000000.0
	L 384 144 384 176 0 0 false 5.0 0.0
	l 448 192 448 256 0 1.0E-4 1.4975247930281652E-6
	r 448 256 448 320 0 0.0010
	g 448 320 448 336 0
	r 448 192 448 128 0 0.18
	w 416 128 448 128 0
	x 296 102 337 106 0 16 wiring
	x 464 194 488 198 0 16 coil
	x 481 293 575 297 0 16 current-sense
	o 3 64 0 35 2.5 0.8 0 -1
	o 8 64 0 34 7.62939453125E-5 9.765625E-5 1 -1
	o 7 64 0 33 7.62939453125E-5 9.765625E-5 2 -1

view raw

Same as SPICE.falstad.txt

hosted with ❤ by GitHub

you can either copy paste the URL or copy paste the raw data and use the “File → Import” function.

3 09 2011

Mark Suppes (20:14:30) :

That works. Freaking awesome!

4 09 2011

Steve (19:06:09) :

Microcap is a professional simulator I use, but a demo can be downloaded that allows up to 50 components, that should be more than enough for what you are doing.

29 09 2011

Discrepancy Between Circuit Simulation and Reality « Prometheus Fusion Perfection (18:53:37) :

[…] Previously we modeled the polywell coils and power supply in SPICE. […]

Prometheus Fusion Perfection