P/S requirements

Design Concepts
1

Hiya MB’ers

quick question:

I have a 15v 3A powerpack

I wish to use this to supply 1x core with a LCD & also 1x MF module

Here’s the question: Can I just connect the 15v to my core and let the regulator on the core board handle the volts down to 5v or do I need to run it through another regulator to reduce the volts to say 9V?

Im a little concerned as I do not wish my 7805 to overheat since it will be running a LCD

If anyone else has used 1 P/S to supply both boards please let me know the best way.

2

The 7805 is rated to supply 1 amp. It’s only going to suck as much as it can give. Should slap a heatsink on him though. Mine get hot when they’r doin nothin. :o :o :o

I got a nice 15volt 1 amp wallwart with your name on it.

Let me know and I’ll courier it to your work. :wink:

Ian

3

::)thanks ::slight_smile:

hey yeah that would be cool.

if you need the address etc give me a bell

4

I’ll get that to you tomorrow Matt :wink:

Ian

5

OK…

I lost sight of my question,

So its alright to have excess amps cause it ill only draw what it needs, but what about the fact that 15v is being pushed in to da 7805 regulator, is dis a bad thing? (7-9v was recommended?)

I also wish to do the same thing for my SID & core.

Do I need to put an extra “part” in the circuit so the voltage to the 7805 is reduced? if so how?

LO