In a previous post we had a look at transistors, in the next few posts we will look at 3 other basic electronic components; resistors, capacitors and diodes.
Let us start with the most basic of the 3 today, the resistor. As their name suggest, they resist the flow of electrical current through a circuit. The change in current can be determined using Ohm’s Law, which states that the current flowing through a conductor equals the Voltage across the conductor divided by the resistance present in the conductor, or I = V/R, where I represents current (measured in Amps), V represents Voltage (measured in Volts) and R represents the resistance (measured in Ohms Ω).
Resistors have coloured stripes along their sides which are used to indicate their values, here is the table used for value lookup:
A simple way to remember the sequence of the colours is with the rhyme:
Better Be Right Or Your Great Big Venture Goes Wrong.
The last stripe indicates the tolerance of the resistor:
Here is an example of how to utilise the table:
The resistor above has 3 colour stripes and a tolerance stripe.
Red Red Brown with a Gold tolerance stripe.
This translates to:
2 2 x 10¹ ± 5% = 220Ω ±5%
Now for an example with a Resistor with 5 stripes:
The resistor above has 4 colour stripes and a tolerance stripe.
Brown Black Black Red and a Gold tolerance stripe.
This Translates to:
1 0 0 x 10²± 5% = 10,000Ω ±5% = 10kΩ ±5%
Here is the schematic used to represent Resistors in a circuit diagram: