In electronic circuits, many different types, frequencies, and shapes of Waveforms are produced such as Square Waves, Rectangular Waves, Triangular Waves, Saw-toothed Waveforms and a variety of pulses and spikes. Each wave has specific characteristics and effects on the human body.
Electrical Waveforms are visual representations of the variation of a voltage or current over time.
This voltage (y-axis) or current variations set out on a graph paper against a base (x-axis) of time, ( t ) the resulting plot represent the shape of a Waveform. There are many different types of electrical waveforms and generally, they are broken down into two distinctive groups.
Uni-directional Waveforms – electrical waveforms are positive or negative in nature flowing in one forward direction only as they do not cross the zero axis point. Common unidirectional waveforms include Square-wave timing signals, Clock pulses, and Trigger pulses.
Bi-directional Waveforms – electrical waveforms (also called alternating waveforms) they alternate from a positive direction to a negative direction constantly crossing the zero axis point. Bi-directional waveforms go through periodic changes in amplitude.
Whether the waveform is uni-directional, bi-directional, periodic, non-periodic, symmetrical, non-symmetrical, simple or complex, all electrical waveforms include the following three common characteristics:
Period: – This is the length of time in seconds that the waveform takes to repeat itself from start to finish. This value can also be called the Periodic Time, ( T ) of the waveform for sine waves, or the Pulse Width for square waves.
Frequency: – This is the number of times the waveform repeats itself within a one second time period. Frequency is the reciprocal of the time period, ( ƒ = 1/T ) with the standard unit of the frequency being the Hertz, (Hz).
Amplitude: – This is the magnitude or intensity of the signal waveform measured in volts or amps