Swahiliteknolojia

Fixed resistors are marked in several ways. These are: Color coding Straight numerical  value Certain numerical codes that can be easily translated Because carbon resistors are small physically, they are color coded to mark their R value in ohms. In memorizing the colors, note that the darkest color, black and brown are the for the lowest numbers, zero and one, through lighter colors to white for nine. Typical Example on How to Calculate the Resistor Color Code Reading form left to right, the first band close to the edge gives the first digit in the numerical value of R. the next band marks the second digit. The third band is the decimal multiplier, which gives the number of zeros after the two digits. Example 1: The first band is red for 2 and the next band is violet for 7. The red multiplier in the third band means add two zeroes to 27. The result can be illustrated as follows: Therefore, this R value is 2700Ω with tolerance ±5%. The resistor t...

There is a lot of confusion in text books and on the web about CURRENT FLOW. WHICH WAY DOES CURRENT FLOW? Current is a flow of electrons. These electrons are negatively charged particles and they are attracted to the POSITIVE of the supply. This means they flow from NEGATIVE to POSITIVE. The first inventors and discoverers of electricity did not know this. They thought electricity flowed from POSITIVE to NEGATIVE. So, they made a CONVENTION (statement) that electricity (CURRENT) flows from POSITIVE to NEGATIVE. They were wrong. But hundreds of text books had already been written, so we have TWO situations. The answer is simple. When we discuss electrical and electronic circuits, we use the old convention, called  CONVENTIONAL CURRENT FLOW  (from positive to negative). To get away from any idea of thinking about "electrons" we say " electricity flows from positive to negative ." We say this so we can follow all the electrical and electronic circuits using arrows...