In the PWM-controlled mode the output currents of the XLC4 control unit are set and adjusted by two external opto-isolated input signals, ON and PWC.
Parameter | Value |
|---|---|
cuPar.WorkingMode | 2 |
The LEDs are switched on with a high level at input ON and are switched off with a low level.
The current for the 4 channels are controlled by the duty cycle of the PWC input.
Resulting output current
PWC is a pulse-width-modulated signal. The duty cycle of PWC defines a current factor F. F is multiplied with the default channel current of each individual channel to set the resulting output current:
I(channel) = Idefault(channel) × F
Duty cycle D
The duty cycle D ist defined as D = tP/T
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Current factor F
The current factor F is defined:
F(PWC) = D(PWC)/0.8 | for 0.1 ≤ D(PWC) ≤ 0.8 |
F(PWC) = 1 | for D(PWC) > 0.8 |
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Pulse width tP and pulse period T
The base currents Idefault(channel) are read from cuPar.DefaultCurrent[0..3].
The following limits are valid for tP and T:
Item | Description | Min | Nominal | Max | Unit |
|---|---|---|---|---|---|
tP | pulse width (high) | 10 | 100 | µs | |
T | pulse period | 20 | 250 | µs |
Additional condition: tP ≥ 0.1 × T