Hi all, thank you in advance for your help in these simple projects that i need help for...
I beg your pardon in advance that I am not from electrical field and a complete novice in this, so any help is hugely appreciated..
Ok this is what I need:

I have 1 LED(small 3mm LED), that will be powered by 3 1.5 volt button cells and 1 switch.
What i need-

1. After a switch on the LED, it automatically switches off after 2 minutes.
The circuit needs to be really simple and small, overall it should fit into a tube 17-18mm in diameter.

2. After switching on, the LED fades-in to full glow in about 30 secs and stays in full glow till switched off. again, overall it should fit in a tube 17-18 mm in diameter.

3. How can i make the LED blink or pulse while its on?

I know i am asking for too many solutions in 1 go but i really really need the help..thank you all...

 

A CMOS 555 will come close, but you need to break it down a bit. Why all the functions?

A modern white LED takes around 3.6 V, this could be a problem. Not insoluble, but it will need work.

 

I would say a small 8 pin PIC micro-controller will do the job nice. But one drawback is that it must be programmed by someone to do this job
Just a tip

 

You know, I don't usually go with µC, but in this case it does make sense. Do they go that low on voltage?

It will have to use BJTs, since it is below what a MOSFET can use (unless I'm mistaken).

 

You know, I don't usually go with µC, but in this case it does make sense. Do they go that low on voltage?

It will have to use BJTs, since it is below what a MOSFET can use (unless I'm mistaken).

My locale component pusher have the 12F629/12F675. I have used them for something like the OP want. They will work in the range 2 to 5.5 volt