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5V reference module
clutch_kick - 19/1/09 at 10:34 AM

Do any electronics buffs on the forum know if I can buy a voltage regulator as a module or kit. The input voltage would be 12-14v DC, I need a very stable 5v output and the unit would be required to handle up to 1Amp or close. Thanks.

designer - 19/1/09 at 10:41 AM

Maplins is the place. But, in Malta?

BenB - 19/1/09 at 10:43 AM

You basically need a 7805 regulator. Depending on the environment you might need to fit some capacitors either side of the regulator. You'll need a hefty heatsink as you'll be turning approx 9W into heat......

BenB - 19/1/09 at 10:50 AM

You could try something like this from Ebay if you don't fancy making one on some stripboard....

ebay linky

iank - 19/1/09 at 10:56 AM

LM2940CT was suggested to me as a better choice for automotive than the older 7805 series regulators. Harder to get, but copes better with the rather aggressive electrical environment. As BenB says for full 1A operator you need a good heatsink.

Can be got from Farnell (and probably RS) datasheet attached to this page.

http://uk.farnell.com/jsp/search/productdetail.jsp?SKU=9490191

02GF74 - 19/1/09 at 11:05 AM

quote:
Originally posted by iank
As BenB says for full 1A operator you need a good heatsink.



locost way is to put some rectifier diodes in between the supply voltage and the input to the regular - the heat will be shared amongst the diodes thus reduce that dissipiated by the regulator hence allow use of smaller heatsink. Obviously the diodes need to be beefy enough to take the heat.

The diodes will protect against incorrect polarity connection too.

clutch_kick - 19/1/09 at 11:35 AM

Wow thanks for the quick replies guys.

MikeRJ - 19/1/09 at 09:05 PM

A switching regulator gives much better efficiency, it won't get very warm at all since the excess voltage is not converted into heat.

Something like this would be ideal if you want a module ready to wire up.