CAD Programs

[darrenyorston]

I am currently attempting to map out the DC electrical system on my boat. I have been drawing the system on paper however it's now getting a bit unmanageable. Does anyone have some suggestions of CAD programs that have common DC components (batteries, switches, winches, radios etc) so I can graphically map it all out?

[Tim B]

QCad has a library of some electrical parts, some you will have to draw yourself.

Tim B.

[marshmat]

The electrical CAD program I usually use is Cadence OrCAD.... but it's designed more for working at lower levels, ie. for designing the radio itself. I haven't tried using it for a layout such as yours. However, if you knew the equivalent properties of each of your devices (ie. you know the voltage and current each one requires, and thus can estimate the impedance), you could use OrCAD to model and simulate the system by representing each component simply by an equivalent resistance or impedance. Then you'd just label them "radio", "winch", etc. and those labels will carry through any calculations or simulations, the calculations work out just fine so long as you check the requirements of each of the real devices. This program cannot give you a layout of how much wire goes in which places, but it is able to simulate the entire system and calculate every imaginable electrical parameter for any point in the system. Thus you can see, when you turn on the winch, how much the voltage will drop at the radio as a result, or other useful stuff like that.
There's a free, unlimited-saves demo version that would probably do everything you want and then lots more. http://www.cadence.com/orcad/ The full version adds more advanced simulators, the ability to control a circuit-board printer, etc. which you wouldn't need. You must be familiar with electrical schematics and have the patience for a learning curve that is very steep for the first couple of hours, but it's a powerful program and very, very useful.

[Tim B]

If you're into programming, I'm starting a Linux-based project called DHelm. Whilst not exactly what you're after it will be able to show on-board electrical schematics, and monitor voltages and currents at certain points.

If you are interested I would be happy to e-mail you the source-code as it is. Most of the electronics class is written, but a good Knowledge of QT3 and C++ is required.

Tim B.