Dc to dc buck converter drops voltage

Thread Starter

Wolf999

Joined Aug 9, 2023
24
Why does dc to dc buck boost converter drops output voltage from 12v to around 1.9v when I connect potentiometer to control amperage?
But voltage controlling potentiometer works just fine.
 

Papabravo

Joined Feb 24, 2006
20,993
Why does dc to dc buck boost converter drops output voltage from 12v to around 1.9v when I connect potentiometer to control amperage?
But voltage controlling potentiometer works just fine.
Without a schematic diagram it is difficult to speculate on the root cause of your observations. I can't believe your expectations of psychic divination.
 
Last edited:

Thread Starter

Wolf999

Joined Aug 9, 2023
24
Without a schematic diagram it is difficult to speculate on the root cause of your observations. I can't believe your expectations psychic divination.
Without a schematic diagram it is difficult to speculate on the root cause of your observations. I can't believe your expectations psychic divination.
Sorry I'm new to electronics, Here I attached a picture of my buck converter.
Without a schematic diagram it is difficult to speculate on the root cause of your observations. I can't believe your expectations psychic divination.
Sorry I'm a newbie to electronics, Here I attached a picture of my buck converter and how I connected the wires.20230810_014643.jpg
 

Thread Starter

Wolf999

Joined Aug 9, 2023
24
What load did you connect? What did you set the current to?
I connected a 120mm LED casing fan to test, I adjusted the amp potentiometer to max level incase it was too low current but still fan stayed off. But as soon as I removed wires from amps pot fan spins back again.
 

Thread Starter

Wolf999

Joined Aug 9, 2023
24
This fan will definitely get burned if it got the full output of 9ah from this converter, But it works fine when I removed amps pot. When checked the voltage it's still at around 1.66v.

Thank you so much for your quick reply and kindness.
 

Ian0

Joined Aug 7, 2020
9,494
We can't tell you anything useful without figures. What is the load (in Amps/Volts/Watts)? What did you set the current to (in Amps)? What did you set the voltage to (in Volts)? And get your units right - Ampere-hours is a measure of battery CAPACITY.
 

Thread Starter

Wolf999

Joined Aug 9, 2023
24
I took 12v from this pc psu. (12v lines have 21Ah)

I have attached a picture of the fan I used as well.

My buck converter is xl4016 and rated for 9Ah.

I used a 100k pot for voltage adjustments and 1k pot for amperage.

So when connected the amperage pot to the buck converter voltage drops down to around 1.6 to 2v. But when I again disconnected the amperage pot voltage goes back up to 12v.

Voltage is perfectly adjustable without any issues when I disconnected the amperage pot.

I adjusted the amperage pot from beginning to end to see if the fan will spin incase amperage wasn't enough. But no matter what position I place the pot nothing changes or even the voltage also. Without any load still same issue as well.

I double triple quadriple check the connections and soldering joints also nothing seems odd. Ah I connected the original small pots that had in this buck converter but still same issue.

I don't know what to do .
 

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Ian0

Joined Aug 7, 2020
9,494
Start with the voltage control.
Choose a few settings, say minimum, maximum and a couple in between.
Start with no load.
measure the output voltage and write it down, along the the voltage it should be.
Repeat with a load.
Then set the voltage to maximum, and connect a 1Ω load.
Choose a few settings of the current control, and write down the measured output current, and the value it should be.
(For a 1Ω load, simply measure the voltage across it to get the current)
 

Thread Starter

Wolf999

Joined Aug 9, 2023
24
Start with the voltage control.
Choose a few settings, say minimum, maximum and a couple in between.
Start with no load.
measure the output voltage and write it down, along the the voltage it should be.
Repeat with a load.
Then set the voltage to maximum, and connect a 1Ω load.
Choose a few settings of the current control, and write down the measured output current, and the value it should be.
(For a 1Ω load, simply measure the voltage across it to get the current)
Thank you, I will do this and let you know about the results.
 

Audioguru again

Joined Oct 21, 2019
6,608
Wolf, you do not understand about electricity. You say the fan will get burned if it got the full 9Ah.
1) It is labelled, 12V/0.15A which is a power of only 1.8W. Then it draws a current of only 0.15A when running, not the maximum current that the converter can produce.
2) How much current in Amps can the converter produce? It is not 9Ah which is 9A multiplied by the usage time. It might produce a maximum current of 0.1A for 90 hours.
3) The battery in my car can produce 600A in winter to turn the cold starter motor. But the clock in the car draws only 0.01A and it does not burn.
 
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