Here is the characteristics of a single pulse. |
The voltage rises very rapidly from zero to its maximum value. It stays steady at the maximum value for a time. It then falls very rapidly back to zero. The duration of a pulse can be anywhere from a very long time (days) to a very short time (picoseconds or less). Pulses do not rise and fall instantaneously but take time (which may be very short). They are called the RISE and FALL times. |
If pulses occur one after
another they are called a PULSE TRAIN.
The duration time of a pulse is called the MARK. The time between pulses is called the SPACE. The relative times are expressed as the MARK/SPACE RATIO. |
Mark/space ratios can vary.
Fig. 3 has a 50:50 mark/space
ratio.
Note that the last three
waveforms are of the same frequency. All the pulses start at the same instant.
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