Potentiometers in a circuit

StevenA

If I add a potentiometer to my circuit will I be able to control the brightness of the LED with the meter?

Crazymechanic

potentiometers are nothing more than variable resistors .so by adjusting it you either increase or decrease both the voltage/current as voltage is relative to current.and vice versa.
Now usually potentiometers are with low wattage so they cannot manage large currents or they will overheat and damage.In the case of a single or multiple led's that is not the problem as led draws few miliamps an average of 20mA I guess.
Yes if you have a let's say 9v battery you can put a potentiometer in series with the Led but be careful as led's have a current limiting resistor.It would be better to use the resistor in series with the pot and the battery.Without the resistor you could accidentally or on purpose turn it to very few ohms resistance and the current through the led would be too high and it would burn down your led (destroy it )

sophiecentaur

A fixed series resistor of about 300Ohms would ensure that the LED doesn't get overloaded. (The LED will take up about 1.5V of the supply volts and that leaves 7.5V from your 9V battery. 7.5V across 300Ohms will give you 25mA when your variable resistor is at zero - safe.

davenn

The only way you are going to effectively adjust a LED brightness is to use a PWM ( Pulse Width Modulation) circuit

There's numerous circuits available online using NE555 timers and a small handful of other components to do this :)

Dave

Bobbywhy

Using the search terms “adjust led brightness PWM 555” Google shows hundreds of opportunities for you to choose from. Here is only one:
http://www.circuitsgallery.com/2013/...ed-Dimmer.html

sophiecentaur

It's all a matter of the level of expertise, surely. PWM could be beyond the experience of someone who has just done Ohm's law but trying to use a variable resistor will show them the shortcomings of the method.

davenn

yup, they will learn how quickly you can pop LED's ;)

D