newbie question

[leedude]

hi, i have just started with electronics, and i was wondering, is there a component out there that would sort of strip off power from a power supply to give a 5v output, as the power supply dropped from 12v?

is this called a zener diode or something?

 

[ante1]

A zener diode might work for low currents and low stability requirements but an LM7805 (there are many others too) will supply more current and high stability!

 

[leedude]

hmm..ok, i have refined the concept a little,
i need the power supply to accomodate an lcd(consumes about 250ma). The input must be a 9v battery, and it must produce an output of 5v. what should i use to build this supply? could i use this: http://www.maplin.co.uk/module.aspx?detail=full&ModuleNo=46321&doy=20m2#more_info

if so, what caps/other components do i use with it? a circuit diagram would be nice.

 

[audioguru2]

What kind of LCD display consumes 250ma? It must have a very bright light in it.
A little 9V alkaline battery can supply 250mA for only a short amount of time. The low dropout 5V regulator will work fine for a little more than one hour.

The circuit diagram for the low dropout 5V regulator is in its datasheet that is in your Maplin link. Use two tantalum capacitors as shown.

 

[ante1]

You must mean 250uA which is more realistic!