Posted Thu, 29 Jun 2023 18:31:23 GMT by Niebergal, Joel
Hi, I would like my 2380 electronic load to not draw any current (in CC mode) when the input voltage is below a certain threshold. 

I see in the "Setup" menu, there are to settings called "maximum voltage value" and "minimum voltage value".
The documentation isn't very descriptive for what these do.
But I expect that if I set the minimum to 2V, that the current draw to be zero whenever the input voltage is less than 2V, but this doesn't happen.

What is the purpose of these two settings ?

Thanks
Posted Mon, 03 Jul 2023 20:16:10 GMT by C, Andrea
In datasheet for the 2380, pg 3 Specifications, it lists the minimum operating voltage.
Suppose you have the 2380-500-15 model and using the low current range (3Amps), the min operating voltage is 0.6V at 3Amps.  It increases to 4.5V at 15Amps for the high range.

This means when operating in CC mode and pulling 3Amps, the 2380 will develop a voltage drop of 0.6V between the HI to LO terminals.  Think of the 2380 as using the output stage of a FET to control the CC mode.
This voltage drop could be attributed to the I*Rds of that FET plus other I*R drops in the path inside the 2380.

Consequently, your device that is supplying the current cannot have a voltage potential lower than this minimum operating voltage of the load.  The load needs to be able to develop at least the minimum voltage drop in order to maintain the CC set point.

In situations where you want to test your device at voltages lower than the minimum operating voltage, use an external (linear) power supply in series with your device.  One floats on the other.
Use the remote sense lines to still measure the voltage only from your device rather than device + external supply.

Otherwise, the entry of the max and min voltages during CC mode should be influenced by the I*R drop and open circuit voltage of the device that is suppling the current to the load.


 
Posted Wed, 05 Jul 2023 17:52:40 GMT by Niebergal, Joel
Hi, thanks for the reply. 

I understand. 
I wish the documentation was more clear on the description, .... as there is NO description of what this setting is.

I would expect these minimum & maximum voltages (e.g. 0.6V & 4.5V) to be fixed for a given model #. 
But it seems not, since these voltages can be adjusted in the setup menu. That's odd. 
 
Posted Sat, 29 Jul 2023 19:30:09 GMT by C, Andrea
Sorry the manual is a bit sparse on it.

The values are adjustable because some applications need different values.
For example, if using the load to discharge batteries to generate battery models, it will be common to avoid discharging the battery beyond its lowest voltage.  A 18650 battery is 3.7V nominally, but stop discharging at ~3.0V.
By using these values the load, you can automatically stay within bounds.

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