How to supply 5V/2A power in a 12V car?

[danci1973]

Hi,

I need to power a 5V device consuming up to 2A of current on a motorcycle (12V battery). I tried using a simple 7805 regulator, but the heat generated is just too much for the confined space under the seat - the plastic has started to melt.

So I figure I need some more efficient way of getting the 5V - enter DC/DC switched converters... Unfortunately my knowledge in electronics is limited to very basics, so I need some already worked-out solution with as little 'special' parts as possible - I mean the coils and transformers - these are always a pain to get or make...

So, to sum it up:

Input: 12V (13.8V)
Output: 5V / 2A (and as little heat as possible)


Thanks, D.

 

[Papabravo]

If you just want to solve the problem then you should be able to buy a module that meets your needs. It might be expensive however.

If you want to build one then I suggest you download a copy of LTSpice/Switcher CAD III. Enter your requirements, and voila a schematic appears that you can use to simulate the circuit. After you succeed with your first DC/DC converter you will gain the confidence to use other chips.

 

[justDIY]

also some other choices for ya, texas inst also has free design tools:

http://power.ti.com

and national semiconductor has a product called web bench that'll design and simulate:

**broken link removed**

national has a "simple switcher" product line that requires two or three low cost external components

 

[Hero999]

**broken link removed**