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Old 02-09-2022, 11:40 PM   #1
jinu_j
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Default XL4015 Step-Down DC Module

Hi Folks

I need help in trouble shooting a "XL4015 Step-Down DC Module with CV/CC Control". This is something i am trying to use to create a variable power supply which will allow me to control/limit both voltage and current. This device has an overall limit of 5A.

But when i am testing this, the voltage control works fine, but the Current control does not. I need help in troubleshooting why the CC is not working. The schematic of this device and the working is explained here Schematic and explanation

The problem with testing the CC is that i have to short the output to get some visible current and then adjust the potentiometer to get the current current value. But when i short the output, the display shows high current flowing but changing the potentiometer has no impact on the current value. What is surprising is that the current value displayed is 9A when the system is supposed to have a limit of 5A. I tried this on 2 units, both show the same behavior.

Any ideas ?

EDIT: found one issue where i had wired the potentiometer wrongly. But correcting that has the following effect. The current (when i short output) always goes to 5A which is the self limit of the system. Moving the potentiometer has no impact on the current. Still continue to be stumped by this.

Last edited by jinu_j; 02-10-2022 at 12:42 AM.. Reason: Some more info
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Old 02-10-2022, 05:21 AM   #2
jinu_j
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Default Re: XL4015 Step-Down DC Module

Finally solved this. For whatever reason if the output voltage is kept below 2V the CC does not work. I am not sure why. I retested the whole thing with an output of 2V and the CC works perfectly. Below that it does not seem to work.
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Old 02-11-2022, 06:05 PM   #3
sam_sam_sam
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Default Re: XL4015 Step-Down DC Module

This is not unheard of this is common for these devices to have a voltage higher than the output voltage
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