Installation Manual

Electrical & Electronic Application And Installation Manual
Production Release Version 1.0
Page 135
11.2 PWM Sensor - Compatibility
11.2.1 PWM Sensor Operation
A pulse width modulated signal is a signal whose voltage is either at a
maximum or a minimum. The duration of the on time as opposed to the off
time determines the strength of the outputted signal. This means that the
outputted PWM signal takes the form of a square wave as shown in figure
11.3.
Figure 11.3 Pulse Width Modulation Waveform
Figure 11.3 shows that the square wave voltage is either fully on or fully off,
the only parameter, which changes is the duration of the on time compared to
the off time. The time between one pulses rising edge and the next is classed
as the pulse width and the ratio within this pulse width of the ON time
compared to the OFF time is defined as the duty cycle. In the case of the
Perkins PWM drivers the larger the duty cycle the stronger the signal.
TIME
VOLTAGE
ON
OFF
PULSE WIDTH
DUTY CYCLE
(50%)
TIME
VOLTAGE
ON
OFF
PULSE WIDTH
DUTY CYCLE
(10%)