General Purpose Circuit Boards at Radioshack

[CogSciFanatic]

Hi..im new here so im not really sure where i need to post this..

I was just curious, at radio shack you can buy general purpose bread boards and circuit boards that you can just put your discrete components into..How do these work? I have a beginners electronics kit, so it has a bread board in it, I was just wondering how I would build a circuit on one of the boards from Radio Shack (i know you solder the parts on to it, i just dont know how the circuit will work properly) I am not very familiar with circuit terminology but I'll try my best to understand whatever advice is given

[ranger]

Solder on a breadboard? A breadboard is used to prototype circuits before any soldering is done.

http://www.iguanalabs.com/breadboard.htm

[CogSciFanatic]

i dont really know what its called...its just got the holes..and its flat thats all i know

[ranger]

So when you said solder, you probably meant in a circuit board and not breadboard. They are two different things. The link above is for using a breadboard. If you're a beginner, it would be a good idea to prototype on a breadboard first. Use a circuit board when you have learned good soldering techniques. In general you would insert components into the circuit board a solder them on the underside of the board.

Probably we are talking about something different because the terminology got mixed up. Post a link to the stuff you bought at the Shack.

[mgb_phys]

CogSciFanatic breadboards (http://en.wikipedia.org/wiki/Breadboard) are a neat way of prototyping circuits without soldering. They are plastic boards with holes that you can push wires into to make connections.

The circuit boards you saw need the components soldering to - but this is a useful skill to learn!

[berkeman]

For soldered prototypes, the pad-per-hole circuit boards from Twin Industries are commonly used (0.1" hole grid):

http://twinind.com/catalog.php?id=7

You can use the blank, non-plated perf boards if you don't want any metal on the boards (like if you're doing high voltage prototyping), or more commonly you would have a metal pad per hole, with plated through holes. You insert the leads of your components through the holes and solder them to the board for mechanical stability, and then connect the components with wire soldered to the appropriate leads to make the electrical connections matching your schematic.

As you plan your assembly, you will look at the schematic and the pinouts and sizes of your parts, and experiment physically with the placement and orientation of the parts. When you are satisfied with the placement, you will typically make a scale drawing (I like to use 2x on engineering paper) of the placement, and add the interconnect wires to the drawing. Then make photocopies of the drawing and the schematic, and as you wire up the circuit, highlight the parts that you have completed on both the schematic and the physical layout copy. That helps to keep your construction work methodical, and cuts way down on wiring errors.

Personally, since most of my prototypes are mixed-signal (using both analog & digital components), I prefer to use the prototyping boards with ground planes on both sides in addition to the plated-through holes:

http://twinind.com/catalog_detail.php?id=115

That helps me to make low-impedance ground connections, to help keep the noise levels low. To make a ground connection, you just solder-bridge the pad to the adjacent ground plane. Remember to make some connections between the top and bottom ground planes with some dedicated holes, though.

BTW, I just noticed that Twin Industries also sells inexpensive electronics kits:

http://twinind.com/catalog.php?id=19

That's a good way to get experience soldering to regular PCBs -- build up a couple fun kits.

[berkeman]

Oh, and one more prototyping tip: It is a good idea to solder down sockets for semiconductors that may fail at some point (like if you miswire something, or over-stress a transistor). So instead of soldering down your 14-pin DIP IC, for example, you would solder down a 14-pin DIP socket, and then after everything is wired up and soldered, you would put your IC into the socket. I typically socket all ICs and transistors in my prototype designs, and sometimes use sockets and carrier things for groups of resistors, caps, diodes, etc.