I'm trying to use the potentiometer to control the brightness of the LED board. (everything works perfectly fine without the potentiometer)
Before adding the potentiometer to the circuit, I tested it with a single LED on a separate breadboard and it worked.
After the potentiometer was added to the circuit, it worked for like 1 minutes with me turning the potentiometer back and forth, then it started to make noise, smell and eventually spark was coming out too.

Here is the schematic:

I checked the voltage and current with multimeter afterward:
I= 0.058 A
V = 12.93 V
so, P= 0.696 W

Is it because the power is exceeding the potentiometer's limit (0.696 > 0.5)? If so, what would be the proper way of modifying the circuit (different types of potentiometer maybe)?

The model for this potentiometer is WH148 (B10k) and it has resistance of 10k, rated power 0.5W according to the website I purchased from.

 

Did it spark like this?

If you turn the pot to short the wiper #2 to terminal #3 then the full voltage of the supply will be across that small resistance.

 

Hello,

When moving the wiper of the potentiometer towards the 12 Volts, you will create a short accross the 12 Volts.
This will burn the part between the wiper and the 12 Volts side of the potentiometer.

Bertus

 

Did it spark like this?

If you turn the pot to short the wiper #2 to terminal #3 then the full voltage of the supply will be across that small resistance.

The spark (maybe it's more like the inside was glowing red) was constant without me touching it. It was exactly like in the video after 39 seconds.

 

The spark (maybe it's more like the inside was glowing red) was constant without me touching it. It was exactly like in the video after 39 seconds.

You've just completed lesson 101 about smoking pot(s).

 

Hello,

When moving the wiper of the potentiometer towards the 12 Volts, you will create a short accross the 12 Volts.
This will burn the part between the wiper and the 12 Volts side of the potentiometer.

Bertus

Hi bertus,

When turning the wiper towards the 12 volts, wouldn't it increase the resistance of the potentiometer which could block the current flow and thus making it an open circuit?

 

Congrats-
You know now how to zap a pot.

Here's the correct way to connect the pot.
R1 is to limit the current to the LED at the zero ohms pot setting (which you may already have).

 

Congrats-
You know now how to zap a pot.

Here's the correct way to connect the pot.
R1 is to limit the current to the LED at the zero ohms pot setting (which you may already have).

View attachment 114808

Hi crutschow, in your schematic, are you using only two pins from the pot, making it a variable resistor?

 

Hi crutschow, in your schematic, are you using only two pins from the pot, making it a variable resistor?

I connected the wiper to one end of the pot but has the effect of making it a variable resistor, yes.

 

You cant dim L.E.D with resistanse that is a bad idea look on youtube how to use LM317T constant current regulators.

 

You cant dim L.E.D with resistanse that is a bad idea look on youtube how to use LM317T constant current regulators.

Yes you can.
Why do you think it's a bad idea?

 

Becuase potentiometer Burns easy trust me just be a pro and use lm317 like in this picture

 

Becuase potentiometer Burns easy trust me just be a pro and use lm317 like in this picture

Depends upon the size of the potentiometer and the LED current.
And I'm a "pro".