1

Hi have this buck converter : Step Down Buck 9A 300W Converter 5-40V To 1.2-35V Power Module XL4016

I've done my research, read some posts and articles but I'm still quite confused, some say a constant current supply "constantly push" the set current, but some say a constant current supply alerts you only when you're about to reach the set current and is current limiting.

Let say my load uses like 1A, and I set my XL4016 Step Down Buck Power Module current pot to 5A.

  • Will my load receive 5A constantly or will the current limiting feature kick in once my load reaches 5A?

Edit: I'm gonna be using the XL4016 Buck Power Module to power some motors for my project, and im gonna buy like 1 or 2 converters for a bunch of 5v sensors and loads, etc. maybe a linear regulator one. But for the 12V ones, im thinking of my XL4016. My input is around 18-14V, i want it to constantly be at 12V, and 5V.

thanks a lot.

princessbubbles15
  • 37
  • 1
  • 8
  • Can't readily find a datasheet or proper documentation on that site. No datasheet, no sale! – Unimportant Apr 05 '21 at 10:29
  • Find a power supply from a reputable supplier that has a proper data sheet is my advice. [What to check for when buying an electronic component or module](https://electronics.stackexchange.com/questions/504044/what-to-check-for-when-buying-an-electronic-component-or-module) – Andy aka Apr 05 '21 at 10:29
  • @winny, im sorry, but i think its not the answer for my question. thanks though – princessbubbles15 Apr 05 '21 at 10:35
  • @Unimportant thats what i thought too T_T lesson learned. im scared of testing it on my project, cause if it will constantly push like 5A when im not asking for 5A, it might ruin my project. I think. and i dont have an electronic dummy load tester. i just bought it because it was cheap. Lesson learned really. – princessbubbles15 Apr 05 '21 at 10:37
  • @Andyaka thanks for the advice. i appreciate it – princessbubbles15 Apr 05 '21 at 10:46
  • 1
    Your question “Will my load receive 5A constantly or will the current limiting feature kick in once my load reaches 5A?” is answered by Olin if you read a d understand his answer. – winny Apr 05 '21 at 10:50
  • @winny, i've re-read the post again, and i understand the current limiting stuff on that post. but i dont know if applies too for my specific device. i guess i need a datasheet like what the others said. thanks anyway. – princessbubbles15 Apr 05 '21 at 11:03
  • 1
    It does. Consider two boundary conditions set by the two control loops on your regulator, voltage and current. As long as output current < set current limit, voltage control takes presence. Vice versa, if you are trying to take more current than the set constant current limit, the current regulation will take presence and voltage will vary below the set point. – winny Apr 05 '21 at 13:45

1 Answers1

1

I'll not comment on the specific device you mentioned for the reasons already clear on the comments.

Will my load receive 5A constantly or will the current limiting feature kick in once my load reaches 5A?

Ideally, a voltage controlled source with current limit would work like this:

enter image description here

If configured for 10V, limited to 5A, start from the blue dot, with no load connected. As the load is increased (you can imagine smaller resistors being connected) the current increases. When the current limit is reached, the voltage starts to drop if you keep increasing the load (reducing the value of the resistor).

Obviously, the lines will not be perfectly parallel to the axes on real devices and other limitations (like power, input voltage, minimum load etc) will be detailed on the datasheet.

devnull
  • 8,447
  • 2
  • 15
  • 38
  • 1
    wow, thanks for that detailed explanation, the graph kind of explains the current limiting concept better. Though, is this concept the same for "most / general " constant current power supplies? thanks :D – princessbubbles15 Apr 05 '21 at 11:10
  • 1
    This is how regulated power supplies with two operation modes (voltage control and current limit) work. There are many types: voltage control with short cut protection and/or thermal protection, constant current only (limited by input voltage without), no regulation at all (open loop) etc... – devnull Apr 05 '21 at 11:16
  • 1
    hey. thank you so much for that, i guess i'll look for a good power supply from a reputable shop. thank you so much – princessbubbles15 Apr 05 '21 at 13:19