300-In-1 Electronic Project Lab (280-0270) Understanding Parts on the Kit Faxback Doc. # 19467 You have probably noticed many different terminals, switches, and controls that are already on the kit and the many colored wires and pieces that you will use to build the projects. The following descriptions explain the purpose of each one of these parts so you can understand what each part does and why you can use it in the different projects. LEDs - are light Emiting Diodes and are located on the upper left corner of the circuit board. These work just like other diodes, except that LEDs light when electrons flow through them. There are eight LEDs in the kit. LED Digital Display - is an arrangement of seven tiny LEDs called segments. The seven segments form an outline that you can use to display numbers and some letters. The display's resistors are already connected inside the kit. The diagram between the spring terminals next to the display show this connection. Cadmium Sulfide Cell or - is a special semi-conductor device that is like a CdS Cell control, except that the resistance of this device changes with the amount of light that falls on its face. To vary the resistance of a control you rotate the knob; to vary the resistance of a Cds cell, you permit more or less light to fall on the front of the cell. Speaker - converts electrical energy to sound you can hear. Antenna Coil - is a coil of wire wrapped around a dark colored rod made of ferrite, a special, form of powered iron. It is used in radio circuits to pick up the signals. It is under the window marked ANTENNA. Output Transformer - constructed of plastic wound with hundreds of turns of very fine copper wire. Thin metal plates called lamination are in the center of the plastic form. It is used to match the output of the circuit to the output of the speaker of earphone. Tuning Control - is a capacitor with a value that changes when you turn its knob. This is called a variable capacitor. It is used in radio circuit to tune to a specific frequency. Control - lets you change resistance values so you can adjust light, volume, movement, and much more. Switch - connects or disconnects electrical circuits. The one we are using is a double-pole, double-throw switch. It can control two different circuits and can Switch them into two different modes of operation. Keys - are another type of switch that let electrons flow when you press the key. When you release the key, the key stops the flow of electrons. This kit has eight keys. Terminals - connect external devices for this kit, such as an earphone, antenna, chassis ground, etc. The kit has two terminals labeled T1 and T2. Breadboard - connects the parts you will use to make the 300 projects. You will wire a major portion of the projects on the breadboard. The board has 665 small holes. These are grouped by row and column as follows: The bottom row is connected to the negative (-) side of the batteries. The top row is connected to the positive (+) side of batteries. The remaining rows let you connect parts to each other and to the top and bottom rows for projects. Each of six columns (excluding the bottom negative (-) row) connect differently, but the five holes across one column provide the same connection point. That is, the first hole in the Row A (first column) is electrically the same point as the second, third, fourth, and fifth holes. The sixth hole is a different, because it belongs to the next column. For example, if you want to connect a part to ROW B, first column, you can connect the part to any of the five holes. The markings for the middle section of rows are A through V, excluding I and O, and 1 through 30 for the hole number. The markings for the top row's columns are grouped as V1 - V6. Each column (group) connects to the positive (+) side of a battery: V1 connects to the first battery; V2 directly connects to the second battery, but also connects to the first battery through the second battery; V3 directly connects to the third battery, but also connects to the first and second battery through the third battery, and so on. Each battery provides 1.5 volts, so V1 provides 1.5 volts, V2 provides 3 volts, and so on. As you go through projects, you will find some schematics show different voltage requirements for different parts of the schematic. Be sure you use the correct voltage supply groups. The marking for the bottom row's columns is a negative sign (-) and a straight line that indicates that all the holes are connected to the same point. It does not matter which hole you connect to. Thus the total number of connection points on the board are 30 holes of 6 groups for positive (+) power supply, 35 holes of 1 group for negative (-) power supply, and 600 holes of 100 groups for mounting parts. (br/all-02/22/96)