convert 24vdc to 5vdc??

[sunmix]

Hi Guys,

Sorry for this question, maybe this question exists in the forum, but I tried hard to source around but failed. How do I Convert 24vdc to 5vdc? I think it needs some transistors or thrysistors to convert it. maybe 2 of them, if im not wrong. Could you guys help me out? Thanks! =)

[kreutz]

What current will be needed on the +5 volt circuit?

[Al_The_Man]

To give a usefull answer it is helpfull to supply a bit more information, what power supply are you converting from? switching? Linear? What Current? Regulated?
For example, if you had a linear non-regulated supply that had a Toroidal transformer, it is far more efficient to add a 5v winding.
Al.

[NC Cams]

Or you can simply add a wall bug transformer for a "quickie" 5vdc.

Even in an industrial cabinent, it is often easier to find a place to craft in a wall bug than to build a regulating circuit, all things considered.

[mxtras]

Why not just use a power supply out of a PC for the 5VDC? You did not mention amps needed but I would assume that since it is 5V it would be for a control circuit - if so, the PC power supply would likely work very well and it will also give you 12VDC (plus and minus) which could come in handy for something.

Scott

[sunmix]

Hmm, i need to have 24vdc for my mechanical relays, so might as well take some from there and convert it to 5vdc.

Al The Man,

The 24vdc is unregulated, from a transformer. Mind explaning the meaning of linear and switching?

If possible, I hope that it's possible to regulate the power supply, by some kind of electronic components...

[One of Many]

To make any suggestions as to specific circuits or components, the current demands on this DC to DC conversion must be known.

What will the 5 volts be driving in total?

There are standard 7805 5volt regulators in several package styles capable of 1-3 amps. There are also DC to DC regulating converter modules in many current capacities.

For now, the missing value in the equation is the amp draw on the output side of your 5 volt supply.

DC

[Al_The_Man]

Again you did not specify the current you need.
To obtain 5v from 24vdc is very inefficient, It seems you do not presently have any supply, so for the 24vdc, if only for relay loads etc, you do not need a regulated supply.
If you can wind a few turns (7~10t) on top of the present transformer winding then feed a bridge and capacitor follwed by a 7805 3 terminal regulator.
Simply put, Linear supply is by direct linear (standard) transformer method, switching is by hi-freq. electronic switching and regulation.
Al.

[sunmix]

I'm not quite sure how much current I need, all I know is i need to drive some Hex Level Shifter ICs and a couple of opto-couplers. Sorry!

[Davidh]

...i made this up. It consists of a 7812 (12v) and a 7805 (5v) power voltage regulator.They cost very little ,are available in 18v and 9v variants. google will tell you more and with better accuracy than I can!

has a few handy ground connections, the spec for the input , from memory is 13 to 30 vdc. outputs are 12v and 5v at the terminals. 1 amp max total load. I use it to drive a little fan (12v) and to supply a pulse generator for manual inching.

PSU

COPPER SIDE

[Holescreek]

http://www.cuttingedgecnc.com/images...ical/24-5v.jpg

[Davidh]

....that's the one