Cr-Led Test Function; Measurement Of Voltage Rise Time - ITech IT8500G+ Series User Manual

3.10.5 CR-LED Test Function

IT8500G+ series electronic load provides LED simulation function. The LED
equivalent circuit is shown in the figure below. It is the series connection of
resistor Rd and voltage source Vf. Its VI curve is equivalent to the tangent of
the real LED nonlinear VI curve at the operating point (Vo, LED-Io) .
Users need to set 3 parameters: Vo, LED-Io, Rd-Coeff:
⚫
⚫
⚫
Therefore, the user can determine the LED-Io according to the rated output
current of the LED power supply, and then calculate the Rd-Coeff parameter in
combination with the VI curve on the LED specification, and then adjust
arbitrarily within the output voltage range of the LED power supply to realize the
real LED simulated pull test for the LED power supply.
Set CR-LED mode
1.
2.
3.
4.
5.

3.10.6 Measurement of Voltage Rise Time

The IT8500G+ series electronic load is provided with special voltage rise/drop
time measurement function. This function gives a simple analog of voltage
rise/drop speed of oscilloscope test power.
Operation methods:
1.
LED-Io
LED-Io represents the rated output current of the tested LED power supply;
Vo represents the forward operating voltage of the LED at the forward
operating current LED-Io, which can be obtained from the VI curve in the
LED specification. The real load is usually connected with n LEDs in series,
so Vo should be set to n times the single-cell parameter , Can also be set to
any value within the output voltage range of the LED power supply;
Rd-Coeff is the ratio of the series equivalent resistance (Rd) to the total
equivalent resistance of the LED load (Vo/LED-Io), that is, Rd-Coeff =
Rd/(Vo/LED-Io). In series applications, Rd- The Coeff parameter is only
related to the VI curve of the selected LED itself, and has nothing to do with
the number of series connections.
Press (Shift)+
value.
Press to save the settings.
Press (Shift)+
LED-Io and Rd-Coeff.
Press to save the settings.
Press key to turn on load input.
Press (Shift)+ keys to enter configuration menu. Press Right key.
Select Measure and press
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keys to enter configuration menu, and set the Vo
keys to enter the setup menu, and set the value of
key.
Functions and Characteristics
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