Electronic Components
Resisters- It resists the flow of electrons in a circuit. It’s value is measured in ohms.

Resistance is the ratio of the current flowing through to the potential difference across a conductor.


Diodes- Two types of diodes are the rectifier and the signal. Rectifier diodes converts a.c. to d.c. they handle high voltages but works at lower frequencies. Signal diodes manage much lower power but works at higher frequencies.

Diodes has current flowing in only one direction. When current flows forward, the resistance is low while in reverse it is high.



LEDs-Also known as light emitting diodes varies in size, shapes and brightness. Red, green and yellow ones are common. It also comes in shapes like rectangles, square and bar shapes.

LEDs can be damaged easily by too much current and thus makes it normal when you see that they are connected to the power supply through a limiting resistor usually within the range of 100 – 330R. the anode of the LED is connected to the positive supply through the limiting resistor while the cathode is connected to the negative supply.


Transistors -Are used to act as electronic swithches and current amplifiers. There are tree ‘legs’- the base, collector and emitter. Current that flows to the base will switch the transistor on and thus letting even larger amounts of current to flow through the collector and emitter. The ratio of the emitter and the collector is the ‘gain’ of the transistor.

These transistors comes in many shapes and sizes and it’s important to decide which transistors is needed at the outset. Voltage and power using capacities, cost and availability needs to be considered. Transistors need at least o.6V at its base. Normally, a 1K limiting resistor is used to protect the transistor, from overheating and its destruction, at the base. Transistors are available in NPN and PNP kinds. And one must always consider all the types of transistors before designing and building a circuit.