Equations used in electronics are frequently written in 'polar form' to mathematically represent the amplitude of an AC signal with its corresponding phase angle. A complementary method is in 'rectangular form', which then enables these values to be drawn as phasors. This is often referred to as j notation. Real numbers (± r) appear on the horizontal axis. Imaginary numbers (± j) on the vertical axis. Positive phase angles are anti-clockwise. Negative phase angles clockwise. Beginning at the +r or 3 O'clock position as 0°. TEST YOUR UNDERSTANDING: We are not suggesting you need an in-depth knowledge of complex numbers to understand electronics, but you do need to appreciate it is possible to represent circuits mathematically if you are to progress onto more interesting applications. This lesson provides an easy-to-understand explanation of the fundamentals. Click through the topics and change a few values before returning several times to gradually improve your knowledge of complex numbers. Note what happens to in the final topic if you make (j) negative.
