Any IC for this problem???

Hi.
Am building a circuit to control a fan with a remote.
Can anyone pls tell me how to do it?
I want to know if there is any IC which gives 12V as o/p when it receives 5V as input. It should give 5V as output until the remote is pressed again. when the remote is pressed again, is should stop giving output. How can this be done??

What sort of remote would you like to use? Wireless RF? Infra-red? Wired?

You mention needing to convert 5v to 12v, where is this voltage coming from and where is it going? There are many different solutions depending on what you are trying to do.

This is an open ended question.

For a project like that, first you must divide the project in subcircuits...for instance: remote receiver, logic, output, power supply.

Then you start working on each subcircuit:
Power supply; switcher or linear?
Output; relay or solid state?
Logic; microcontroller or discrete?
Remote; Infrared, RF, other?

Then you start asking questions relevant to each subcircuit, fo instance, if you decide to go the microcontroller approach, you may ask whether to use Atmel, Microchip, etc.

am using RF receiver and transmitter. just tell how to do this. when the remote is pressed once the i should have o/p of 5V. if it is pressed again there should be no output... how do i do tat?

go to Digikey and look at their wireless section of components. They have loads of stuff thats already built and capable of doing any type of remote switching you would ever need, and for cheaper than you could ever build one!

So you already have the transmitter and receiver. The receiver outputs 5V after the first transmission and then stops outputting 5V on the next transmission.

You want a device that accepts the 5V and provides 12V to some device.

Do you have 12V available?
Can it provide enough power to run your 12V device?
Do you know what a relay is?

I understand what you need.
You need a flip-flop to toggle the output.

Use a CD4013