Circuit design question. Prototyping.

AI Thread Summary
The discussion focuses on creating a sequential tail light kit using a 556 chip, with participants sharing methods for transitioning from a breadboard setup to a durable, weatherproof circuit. Options include etching a PCB using the toner transfer method, which is cost-effective and straightforward, or using a mechanical PCB router for more precision. Participants also suggest using perf-board for hand wiring if a layout isn't desired, and recommend conformal coating or potting compounds for weatherproofing. Free PCB CAD software options for OSX are sought, with Pad2Pad mentioned as a useful tool despite its limitations on Windows. The conversation emphasizes practical approaches to prototyping and circuit design for automotive applications.
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Some of you may have seen my thread where i am using 555 (more then likely a 556 instead)
to make a sequential tail light kit for my car. Its a pretty simple circuit that really only consists of the 556 chip, a few small caps, and a few resistors then the relays (currently using LEDs to get everything setup correctly)

Ive just about got it set up correctly i just need to perfect the timing of the cycle. The next problem i face is taking my breadboard setup and making it into something i can actually use.
Ive seen where you can buy copper plated chips and etch them yourself but it that the best method? I need something that will be durable and preferably something i can weather proof a little bit.
I googles a little but "circuit design" is pretty broad.
Can anyone point me in the right direction?
 
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It really just depends on what you want to do. If you want to learn to etch a board, that option is always there. You will have to do some type of layout first and then drill all your holes, plate the board, etc.

If you want a more 'hands-off' approach, you might want to have boards made. There are freeware layout programs that prototype boardhouses use (sunstone.com for example has one). Just Google prototype PCB and you'll find several links.

If you really don't want to do a layout, you could always just get some perf-board and hand wire your circuit.

If you want to weatherproof the design, there is always conformal coating. You would also use a potting compound to seal the circuit if you are still worried about the elements.
 
For small size and quantity semi-permanent applications, I prefer a perforated grid proto board with copper strips like the Radio Shack http://www.radioshack.com/product/index.jsp?productId=2102845
The 0.1"" grid is perfect for DIP and miniDIP ICs (and sockets), and works well with transistors also.

Bob S
 
You can use "press and peel blue" and ferric chloride to etch your PCB design on a copper board. This is probably the simplest approach to a PCB prototype.

You essentially print your circuit with a laser-jet printer onto the blue film, iron onto a copper board, peel off the blue, and etch the remaining copper with ferric chloride. It works pretty well although very fine pitch work can come out a bit shotty.

A more elegant way is using a mechanical PCB router. I use one at my work from LPKF. It mechanically removes the copper (like a cnc machine).

For a simple circuit, try out the press and peel - you could probably make a circuit for <20 bucks and have plenty of material left over to make more boards for later designs.

-Joe
 
EDIT: Actually i found the source of my confusion...
To shorten my post i have decided to etch my own board using the toner method (assuming i can find a printer to use!)

Does anyone know of some easy to use (free) PCB CAD software for OSX?
Im currently using Pad2Pad which has proven pretty easy to use and useful but i have to run windows on parallels which slows things down a little.
 
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