Schematics and Component Connections

Which way you start is your preference, but I do not recommend changing directions as you go along. I usually work from positive to negative because this convention is more traditional, but it is just as easy to work from negative to positive.

The important things to remember when wiring an electronic circuit are:

1. Be sure that the power is disconnected while you are making connections.

2. Use the right tools for the job.

3. Work methodically to avoid making careless mistakes such as crossing wires, reading the schematic incorrectly, or failing to make a connection.

4. Work carefully to avoid making poor connections that could cause your circuit not to work properly and possibly even damage your electronics.

5. Check over your work carefully until you are fairly sure that you have made no obvious mistakes before you turn the power on. (A good fast check is measured circuit impedence with an ohm meter compared to calculated values on your schematic.)

What component should be connected first?

The first component to always connect first is any chips that you may need for the schematic. Other than that, it usually does not matter. Being able to see the schematic you are referring to would probably help also.

What direction should the components be connected?

Resistors as well as inductors do not matter which way their leads are connected. Capacitors can matter depending on what kind of capacitor you have. Look closely at the capacitor, is there any "+" or "-" marks? If there are none to be found (and you are sure it wasn't rubbed off accidentally), chances are you have a ceramic capacitor. Ceramic capacitors are not polarized, so just like resistors and inductors, the orientation into the board does not matter.

If there are "+" or "-" marks on the capacitor, there is a certain way they need to be connected. The side of the capacitor that has the sign denotes which of the two leads are "+" or "-". You want to insert "-" (or the side that isn't "+") toward ground, if you are only working with positive voltages. If you are working with negative voltages also, the "-" lead is connected to the most negative voltage (for example: the "-" lead would connect to -9V instead of -5V [or ground]).

For Supplemental Information on Components, go to these blog entries:

Electronic Projects for Beginners - Components (Part I)

Electronic Projects for Beginners - More Components (Part II)

I typically place the smallest components first. That means I place resistors first, followed by smallest sized capacitors. I then solder all the resistors and caps to the pcb board and only if I am satisfied all is placed correctly. During this placement, it helps to build knowing where the POS and NEG traces are. I build outwards from a major component such as IC...helps with understanding my pcb layout during large jobs. Understanding prevents many errors. I also build regards to function....I start with the input side and finnish at the output side. I don't ever recall using the POS and NEG traces as a main guide to placement. You might prefer a different way. Do what is easiest for you.

Larger components are added such as the larger sized capacitors, pots, relays etc.. These are also soldered once I am happy all is correct. Trying to fit a resistor between to large parts is not an easy task, which is why I normally place and solder the smallest first. The IC's are the last to go on to prevent damage. DIP sockets are great and if you can use them, put them on first, otherwise just draw on the pcb where your IC's are to go and build outwards from them.

A step-by-step approach is ideal for large projects. Start with grouping identified functions of particular components and place them onto the board using method mentioned above. This helps with preventing errors of placement, as an understanding of what the components do in a given group prevents crazy placement of parts.

There is a stash of information on the WWW regards how to solder too. I bet also you get heaps of advice from others in this forum