circuit boards?

Question

I am building a robot for school. Its just a simple one, but I was wondering if anyone knew of an ultra beginners guide (online) to making circuits?
Ive been looking at this sight: http://www.robotroom.com/HBridge.html and I have that book too, but I cant figure this stuff out.

acctually, I am using a "perf" board. I just need to sauder my circuits with wires. But I dont understand the layouts of circuit boards...

Answer 1

You can make your own PC boards using a Toner Transfer Method where the PC image printed by a laser printer is ironed onto the PC board. The board is then etched in Ferric Chloride (available at Radio Shack)

There is special toner transfer paper from Pulsar available at Digikey.com

Answer 2

You don't need to make a printed circuit board (PCB) if you want to experiment with circuits. PCBs are useful if you want to make many identical circuits for production purposes, but it's a lot of trouble to go through for just one circuit. Also, if you want to change the design, it becomes difficult. as one has to cut tracks and solder wires all over the place. Another method is wire wrapping, but it's not good for fast circuits.

The easiest way to make a circuit is to get a plain copper sided board and place the components (upside down like dead bugs) directly onto the copper, regarding the copper as a ground plane. You can use glue if it is necessary, but often it is not as the wires hold the circuit onto the board/ground plane. If you don't have plain copper sided PCB, you can use a copper sheet or tinplate. Some containers for candies etc are tinplated steel which are easy to solder on. It works very well even for high frequency circuits and is called the "dead bug" construction method. Search Google for "circuit prototyping" and "dead bug" construction. An excellent reference for this type of construction (especially the pictures!) can be found here:

http://www.linear.com/pc/downloadDocument.do?navId=H0,C1,C1154,C1009,C1028,P1219,D4138
(Application Note 47: High Speed Amplifier Techniques by Jim Williams)

Answer 3

Those diagrams and instructions on the site you mentioned assume that the reader already has a basic understanding of electronics. Best thing I can recommend is that you go on www.radioshack.com and order some books about basic electronics to get started. Also, Radio Shack has some basic kits and supplies for making circuit boards. Good luck with your project!

Answer 4

Honestly, You need a lot of chemicals to make circuit board. I know this b/c my husband is Process Engineer for a circuit board company. Drilling, routing, it's a long process. I was able to find a website. I really hope it helps. GOOD LUCK!!!!

http://onyx.boisestate.edu/~jcofflan/CPM/Circuit_Board.html

Answer 5

You need layout software. Try ExpressPCB at www.expresspcb.com. It's free, easy, and I've used it several times. It's a great way to see how your circuit is going to look before you build it, or to see how well parts fit together with the pitch and trace layout you try to use. I've actually used the software to print out my traces, transfered the layout to copper clad, and etched my own circuit with etching solution.

Answer 6

Before actually building your circuit on perfboard, do a good layout drawing. It usually takes me atleast a few attempts to get a layout I am happy with. Try to minimize the number of wires you will have to cross. A lot of visualization and creativity is involved. (Ex. What if I rotate this part 180 deg, and put these two over here and move this connector to the other side of the board...) Routing can be a little daunting, but just find something that looks reasonably good and go with it.

As for the interconnections on the perfboard, you will need to use jumper wires or components themselves to do the routing.

Here are a few guidelines that might help you out.

Don't route a wire under an IC. Axial leaded components are okay to route wire under, just make sure the component in not setting directly on the wire.

For Perfboard, keed your IC's connectors and large components on the top side.

Route wires with neat corners, don't be afraid of using extra jumpers to cross wires (manhattan) and don't be too concerned about trying to minimize wire lengths..

Attach the wires to the circuit board with clips, clamps or glue to avoid putting stress on solder joints.

Wires should not be tight, but not be so loose they will snag on things or form large loops.

Use heatshrink tubing or cable ties to contain bundles of parallel wires. (not electrically parallel, just running the same direction)

When attaching a wire on the top side to a component lead, wrap the lead about half a turn around the component lead on the top side, then solder.

When attaching a wire on the bottom of the board, stick the wire up through the same hole as the lead, then solder on the topside.

Bend IC leads outwards to hold them to the board.

When branching a line, Use a short peice of solid wire with no insulation routed through the perfboard vertically (home-brew via), then wrap (about 1/2 turn) and solders wires to the top and bottom. (much prettier (and reliable) than wire splices.

Don't route multiple wires to a component lead. Instead, route the wires to a "home-brew via" and run a single wire from the home-brew via to the component.

If running wires off the board, loop the wire down and back up through the board to serve as a strain relief.

For wires carrying appriciable current, (power and ground connections) Route the forward and return wires near each other. Or better yet, spiral the wires together.


Now for some soldering tips (Pun intended!)

Use plenty of flux, and don't forget to clean off the flux when you are done, unless you are specifically using a no-clean flux.

Make sure your iron tip is the proper size for the job. Your goal is to get the solder to flow quickly onto the wire and component lead. If you iron tip is too small, even if your iron is at a high temperature, you will have to apply heat for too long to get a good solder joint, and risk damaging the component you are soldering to.

Touch the iron tip to both surfaces you are soldering at the same time. Then quickly touch the solder to the connection and watch the solder flow and wet the two surfaces. When enough solder has been applied remove the solder, and then remove the iron. The whole operation from start to finish should take about 1 to 2 seconds. The solder joints should have a shiny smooth appearance (tin-lead solder) with a concave fillet and the lead still visible at the top of the joint.

Get consistant looking solder joints by putting a bend in the solder wire to measure the amount of solder going into each joint. Just melt solder into a joint until you reach the bend. If you make your bends the same distance from the end, you will always apply about the same amount of solder to every joint.

Keep your soldering iron tip clean and tinned to improve heat flow.

You can apply a very small amount of solder to the iron tip to act as a heat-bridge and improve heat flow from the tip to the joint.


I hope that is enough to get you started. They don't really teach this kind of practical circuit construction in college. Which is a shame, in my opinion. If you are really serious about getting good at circuit construction, you will have to learn a lot on your own. There is an organization called IPC that sets quality standards for Electronics Assemblies and they publish some good reference documents about circuit construction methods.

Here is a website that has actually contributed their material to the IPC documenation. (But you can look at it for free on their site!) The guidebook is for rework, but many of the techniques will be applicable.

http://www.circuitrework.com/guides/guides.shtml

Answer 7

One of the main things is to keep the resistors away from the board or another resistor. The heat will cause other components to deteriorate also.