Author Topic: LED Dimming  (Read 191 times)

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Offline dlad87

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LED Dimming
« on: April 12, 2021, 02:09:48 am »
Hello,

I’m looking to dim a standard 5mm led based on the position of a 100k volume pot.

Not sure if it’s possible to do so using a single gang pot that is already controlling the volume of a mono audio circuit?

I am also not opposed to using a 100k double gang pot (one side for volume and one for the led) but am still not sure how I would supply the right voltage range to the led with the 100k value pot. Not sure if there’s some kind of led driver that could do the job or some kind a CCS.

The supply voltage is 9 volts.

Thanks
« Last Edit: April 12, 2021, 02:13:49 am by dlad87 »
 

Offline ledtester

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Re: LED Dimming
« Reply #1 on: April 12, 2021, 02:23:45 am »
There are two ways to control the brightness of an LED:

1 - control the current going through the LED

2 - turn the LED on and off with a duty cycle between 0 and 100% (PWM dimming)

Both methods will require extra circuitry.

Here's a link to PWM dimming an LED with a 555 timer:

https://www.electronicshub.org/pwm-led-dimmer-using-ne555/
 

Offline dlad87

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Re: LED Dimming
« Reply #2 on: April 12, 2021, 02:52:30 am »
Thanks,
I was reading that earlier. Would that circuit work with a 9V supply? And what effect would it have using a 100k pot instead of a 50k?
 

Offline ledtester

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Re: LED Dimming
« Reply #3 on: April 12, 2021, 04:42:50 am »
I would just try it - you won't blow anything up.
 


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