Spice Circuit simulation Program

I was talking to on of the Electrical Engineers at work about possible software to aid in circuit design that may also have test/diagnostic features to actually test a circuit. This was yesterday and he said nothing that he knew of. Then this morning he mentioned this Spice/Probe-Spice program from the the University of California in Berkley that he remembered using in college. Anyone have any experience with it? Think it'd be useful or just not practical for an electric brew system?

IrregularPulse said:

I was talking to on of the Electrical Engineers at work about possible software to aid in circuit design that may also have test/diagnostic features to actually test a circuit. This was yesterday and he said nothing that he knew of. Then this morning he mentioned this Spice/Probe-Spice program from the the University of California in Berkley that he remembered using in college. Anyone have any experience with it? Think it'd be useful or just not practical for an electric brew system?

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Spice has been around forever. It is really used for electronic circuit CAD and simulation. I think it is not really geared to electric circuit analysis although I have not used it many years. I am much more familiar with Matlab and Simulink.

I have a very little bit of experience with it. SPICE is really just a backend to a number of circuit analysis programs, try looking for 5spice or the student edition of Pspice. If you can find a decent tutorial and have a decent knowledge of electronics they can make designing and testing complex circuit easier.
I dont think it will be very helpful for wiring heating elements or solid state switches but if you are going to design your own timers / temp controllers it could be very useful.

Sawdustguy said:

Spice has been around forever. It is really used for electronic circuit CAD and simulation. I think it is not really geared to electric circuit analysis although I have not used it many years. I am much more familiar with Matlab and Simulink.

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It actually is used for circuit analysis...it is similar to NASTRAN in that really it is an analytical solver that has had various versions of the same tool, and many front-ends put on it over the years by different companies and organizations.

If you look around, you can still get the original SPICE code(s) and write circuits into it using a text file. It does have the ability to analyze some solid-state devices, but if you are trying to simulate something like a fully integrated PID or similar device, it's unlikely you'll get that working very easily.

A quick google turns up this helpful Wikipedia page with links at the bottom to both program source and tutorials.

Yeah, spice is for some pretty hardcore circuit analysis. We use it in my industry for characterizing the timing and transition rates of teeeeeny tiiiiiny transistors and whatnot.

I don't know exactly what it is that you want to tinker with, but SPICE might be more than you really need.

What kinds of stuff are you wanting to simulate? There are a number of circuit design and simulator tools out there for free that might be more suited to basic tinkering.

I found this one when messing with the idea of building a pulse width modulator.

Just unzip the thing and double-click the "index.html" file in the directory to pull open the loose manual and launch the simulator.

it has all of the basic things like resistors, capacitors, inductors, as well as a few IC's (like 555 timers) and digital logic gates, relays, toggle switches, etc.

You can simulate the circuits and enable visuals to show you current flow as well as power consumption, and you can click nets in the circuit and add them to an oscilloscope display at the bottom of the design window.

It's all Java based and it worked just fine for what I needed it for.


Oh, DAMN! The file is too big to attach to the message!

Ah! Found the website I originally copied it from.

http://www.falstad.com/circuit

Here's a freebie from Linear Technology - its been a while since I've used it (an older version of it) but I recall it being pretty simple to use.

http://www.linear.com/designtools/software/ltspice.jsp

check out micro cap. I've used quite a few of these programs and it is by far my favorite http://www.spectrum-soft.com/index.shtm

I used PSPICE in college, I have an Electrical Engineering Degree. I don't see how it would be remotely useful in setting up a E system. That is unless you are designing the PIDs and controllers yourself. If that is the case, I hope you have a Masters or a PHD in EE.

I've used every tool above. I do electronic design every day. None of them are going to help you build an electrical brewing system.

Actually, I take that back. There is a 555 simulation in the falstad link that would be useful for building a PWM controller. I tried it once somewhere in the past (pretty neat really).

passedpawn said:

I've used every tool above. I do electronic design every day. None of them are going to help you build an electrical brewing system.

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well... i used that one I linked to test my PWM circuit, driving a relay, which drove a low ohm resistor with 240VAC, so.....

passedpawn said:

Actually, I take that back. There is a 555 simulation in the falstad link that would be useful for building a PWM controller. I tried it once somewhere in the past (pretty neat really).

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ok, i take my previous post back ,too.

SPICE is for analog circuit design, genuinely for things working over a very wide bandwidth. It's spectacularly useful for audio amplifier or HAM radio design, but not too useful for your purposes.

I'd recommend just going with an Arduino. It's a less expensive, more powerful relative of the Basic STAMP - easy to program, and capable of interfacing with analog sensors and PWM-driven servos.

It does seem like overkill. I'm basically just looking to draw up a schematic for my brew rig and test it before wiring it all up. I suppose I'm a product of my youth and I tend to think of software before pencil and paper. I'll likely draw it up and post it here for eval.

I'll be running a 240V 50A line and powering two PIDs, two Heating elements (1x120V 2000W and 1 240V 550W) 2 SSRs, 1 pump, 1 120V stir motor and the indicator lamps for the control panel. Should be simple enough. I have an electronics back ground and education and minor experience in automation. It's just been a couple years since I've had hands on experience. (Took a desk job to get off the road )

I'm probably less experienced than you are, but nothing you're doing would require SPICE. It sounds like it's all digital - just "on and off". Unless you're using some sort of homemade 3-phase generator for the motor, you should be just fine without it.

You could probably run the whole thing off a computer's parallel port.

Here is a free schematic program. I've heard good things, but I haven't even downloaded it myself (I own other).

PCB Artist

I'd recommend using EaglePCB. It's not too hard to use, you can send the files to any manufacturer (including the extremely cheap Olimex), and best of all, it's free (though you're limited to small PCBs for the free version, modularization is not a bad thing.)

http://www.cadsoftusa.com/

I really was just looking for software I could lay out my siwtches, buttons, pump, elements and the wiring instead of using pencil and paper. Something that would say, Whoa!!! That won't work, would have been a neat feature

All I do all day every day is work in Hspice.... If anyone has any questions feel free to PM me...

As stated above, it's a circuit simulation tool. There really isn't anything brewer's do involving circuits that can't be solved on the back of a napkin.

If you want to build your own circuit for something it could be of use. But, I have never seen a thread about someone building a grass roots transistor circuit on this forum.

jusware said:

I used PSPICE in college, I have an Electrical Engineering Degree. I don't see how it would be remotely useful in setting up a E system. That is unless you are designing the PIDs and controllers yourself. If that is the case, I hope you have a Masters or a PHD in EE.

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LOL, Some one owes me a degree then.

I use the aforementioned LTSpice quite a bit, works great for a freebie. It won't do what you need to do though.

Your best bet is it write up a control narrative of how you want the system to work and draw out how you think it should be wired. Then post it up for one of us controls guys (ie code nazis ) to take a look and comment.

jusware said:

I used PSPICE in college, I have an Electrical Engineering Degree. I don't see how it would be remotely useful in setting up a E system. That is unless you are designing the PIDs and controllers yourself. If that is the case, I hope you have a Masters or a PHD in EE.

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Yea, I have zero need for an advanced degree and I've designed a gazillion things more complex than a PID.

Typically, a PHD isn't going to design anything. If they were gung ho about building stuff they would have got out of school and done it.

Seriously, I designed microprocessors as an undergrad.