Variable voltage and led

[Shaam]

Hello,

I want to mount a circuit which switch on different LEDs at different voltages.
For example, lets say I have 3 LEDS and i want them to light up at the voltages below:
5V, 1st LED
8V, 1st and 2nd LEDs
12V,1st, 2nd and 3rd LEDS.

For varying the voltages, i will be using a 10K potentiometer.

I need a simple circuit with basic components. I will be trying this circuit on a breadboard.
Thanks in advance.

[pebe]

It can be done with comparitors. However, to design a circuit you must state exactly what you want - not just 'for example'.

[PradeepKumar]

Comparators is the right option to go with. Just try using that one to see good results.