what is max i/p voltage for normal led and power led?

hi,
any body can help me to know what is max input voltage can give to normal led, as well as for power led?

It varies according to type. Check the data sheet for the particular type of LED.
Typically for a single 'normal' red LED it will be about 1.6V and a little higher for other colors. For 'super bright' LEDs using fluorescent dye the voltage is usually around 3.5V per LED regardless of color. Most 'Power' LEDs use several individual fluorescent LED dies inside one package so the voltage will be a multiple of 3.5V.

You should understand that you do not actually provide a voltage to an LED, you provide a current through them and let the LED set the voltage itself. They are essentially constant voltage devices which means that if you provide them with less voltage than they want, they either don't light at all or are very dim, if you provide them more voltage, even a small amount, they burn out. What you shuld do is control the current to set the brightness within it's permitted range and accept the voltage at whatever it happens to be.

Brian.

If u are meaning to ask "at what voltage the LED will burn" then the asnwer is- it will not burn at any voltage as long as the current is within the max rating limit as rightly mentioned by betwixt.....