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at any given time. Voltage or current source is applied to an analog load in the form of ON
or OFF repetitive pulse sequence. When it is on, DC power supply will be applied to the load;
when it is off, DC power supply will be disconnected. If only the bandwidth is wide enough,
any analog value can be encoded by PWM. The output voltage value is calculated by the
on and off time. V
out
= (T
on
/ T)*V
max
.
We can see from the top oscillogram that the amplitude of DC voltage output is 5V. However,
the actual voltage output is only 3.75V through PWM, for the high level only takes up 75% of
the total voltage within a period.
Here is the introduction to three basic parameters of PWM:
1.
The term
duty cycle
describes the proportion of 'on' time to the regular interval or 'period'
of time
SunFounder
