Electronic Projects for Beginners - Notes Concerning Chips (Part V)

Part I and II focused on components, but I felt that chips needed more clarification before I begin to use them in a project. This entry focuses on all you need to know about chips before you insert them into the breadboard. Different projects will focus on different kinds of chips, which will be discussed as they are presented.

Inserting Chips Into Breadboards

When inserting chips into the breadboard, it is very important to insert them as pictured to the left. Notice that four pins of the chip are on the left side of the trench that is running through the center of the breadboard and four pins are on the right side.

Not inserting the chip over this trench can lead to chip malfunction and even breaking (in the electrical sense, you will not see a large crack running through the chip denoting its disrepair). Chips may do various things when they break like let out smoke or get very hot. Sometimes they get so hot that the top of the chip starts melting away and you can see the glowing red of the internal connections (I have witnessed this once, not my doing, mind you), so proceed with utmost caution when touching chips if you think they are bad while power is on.

If you ever see smoke or smell burning after turning the power on or attaching the battery, turn it off or remove the battery immediately. This indicates that something is not wired right and you fried a component and it will no longer work. If you hear a "pop" noise, this could indicate an LED or capacitor has broken. If you see black or brown scorch marks on an LED, capacitor, or other component, replace it.

Orientation and Pins

The next most important step besides inserting the chip in the right part of the breadboard is to have the right orientation. As a basic rule of thumb, it is best to keep all chips on the board all orientated toward the top of the board, or at the very least, facing the same direction.

The image at the right has labeled the 555 timer chip. Every chip has either a notch or an indented spot. The notch indicates the top of the chip with the top left pin being pin one. The pins are sequentially numbered counter clockwise around the chip. Most chips have more than eight pins, but they are still counted in the same fashion. The indented spot usually indicates pin one on the chip and can also be used as a reference as to which end is the top.

Type of Chip We Will Be Using

When choosing chips, there are many different package types available. Certain packages are meant to be used for various things, which I will not discuss in this blog. The package type that is used for a breadboard is DIP, which stands for dual in-line packaging. Variations of these packages include CERDIP and PDIP which are distinguished for their packaging material.

Chips and Schematics

As you can tell from the example schematic to the right, the pins on the chip are labeled, although not in the correct orientation around the chip. On the schematic, the first pin (top left) is labeled "2". This corresponds to pin 2 on the chip (second down on the left side), NOT the first pin on the left (as the orientation on the schematic would suggest). When connecting wires to the pins, make sure that the pin number on the schematic corresponds to the pin number on the chip.

Notice also in the example schematic that lines cross. The lines that cross and have dots on them are electrical connections, but the lines that cross without dots are not meant to be electrically connected. Sometimes in order to make schematics visually appealing, they need to cross lines, but make sure there is a dot on them before connecting them electrically.

Part VI of this series will kick off the project making portion of the series. This project starts by using a 555 timer to make LEDs blink. This project will also lay out the steps needed to produce the resulting frequency from a speaker.

Previous Blogs in Series:

Electronic Projects for Beginners – Components (Part I)

Electronic Projects for Beginners – More Components (Part II)

Electronic Projects for Beginners – Reading Components (Part III)

Electronic Projects for Beginners – Translating the Schematic onto a Breadboard (Part IV)