converting 5v to 12 V

I have a question..I know Arduino Uno just gives 5v as output..But i need 12 V as output..How can this be done?

Use a transistor to get the 5V output up to 12V. You will also need a 12V power supply for the transistor to pull up to.

which transistor should I use …Any suggestion?

Any NPN transistor wil do. I use a BC183 but there are hundreds like the 2N2222. Use the cheapest you can find.

could you provide me a schematic of the circuit? I was using NPN B331 transistor..I connected base to ground,collector to 12 V and emmiter to 5v..is that how it is suppose to work?

Why do you need 12Volts. give us a URL to the device needing 12 volts.

could any one help me out to convert 5 V to 12 V...Arduino gives 5V but the device that i have needs 12 Volt..Some one said using NPN transistor will work? any one has schematic for that...can i use the relay? I do i do it..ANY HELP

you will still need something to provide the 12 volts, then something else to interface it with the arduino (which is where the transistor comes in)

What kind of device are you trying to power? Maybe a MOSFET can do the trick http://www.youtube.com/watch?v=Te5YYVZiOKs

A npn transistor to begin with.. 1k resistor from your arduino pin to the base pin...

Then your 12v device + side takes the 12v+ rail on the NPN emitter connects to ground... the - side of your 12v goes to the collector...

If it's not a device, place in an appropiate current limiting resistor.

I am just using arduino to operate electromagnetic lock…It needs 12 v supply

If the lock needs 12 volts, the arduino can not supply it,

what you need is an external power supply ( PSU ) that provides 12 volts, this could be a mains block, or a battery, depending what you have.

You then use the arduino to switch this 12 volts on / off to the lock.

the arduino would drive something like a transistor or a relay,

circuit 7 or 19 might help

http://ruggedcircuits.com/html/circuit_-7.html

http://ruggedcircuits.com/html/circuit_-19.html

G'day sir. The easiest way. If you do not wish to add an 12V external supply is to build a step up converter (smps). This can be done very easily using a controller made for the purpose.

National (now TI) have made some very easy to set up IC's. You do however need to set up some external components. An Alternative could be to buy a small DC/DC converter and use that.

I don't think we really know what he wants. We don't know if he has a 12volt power supply or not. I think he just needs the signal from an output pin, to trigger something at 12 volts. I ask what he is trying to trigger, but have not yet received his answer. Maybe today.

That is true, we don’t really know what it is for. In case it is only a high signal a voltage multiplier could also be a solution.

If you're going to covert without external power then be really careful about how much current you draw. Arduino IO pins are not good for much 5V, not recommended for more than 20 mA of 5V, or total from the board of 200 mA so how much 12V would you expect to get out?

It's better and cheaper to use external power and be sure to connect the grounds unless you use an isolator to level up with.

As far as we know, he may have a 12 volt external source. He's not saying. So I am not guessing!

I just need to make the electromagnetic lock work which nerds 12 v suppy..

I can have 12 v battery ...

I paid $3.50 for a 12V 1A wall wart...