I have three Switch-Mode Power Supply options. I need to go from 12V to five 6V @ 500ma devices (based on label on devices). The devices will also work fine at 5V, but I'd feel better with 6V.

OPTION A: 5V 600MA SMPS

12V input, 5V 500MA output. But it's only 5V (would work though). And I'd need to buy five of these and wire all 5 separately.

http://www.pololu.com/catalog/product/2107

OPTION B: 6V 600MA SMPS

12V input, 6V 500MA output by means of a potentiometer. I'm wary of trusting my own setting of the pot, but I assume I just hook my multimeter up and turn the little screw until it reads 6.00V? If so, this would be perfect, except I need to buy 5 and wire all 5 separately. See Option C.

http://www.pololu.com/catalog/product/2103

OPTION C: 5V 7A SMPS

12V input, 5V 7A output by means of a jumper. I could run all five devices off just this one $25 board with plenty of headroom (I only need 2.5A worst case scenario) for future additional devices. However, it's only 5V, and while 5V works fine, I'd be happier getting 6V "just cause".

http://www.pololu.com/catalog/product/2111

So what would you choose and why would you choose it?

And if any of this is wrong (possibly is), please let me know. I'm also open to other companies/suggestions. An SMPS that outputs 6V at 2.5A or higher would be PERFECT.

 

I would buy the last one , one psu minimum hassle, cheaper.

Or can you not use an LM317k regulator ready made and set your own voltage level?
http://www.ebay.co.uk/itm/Voltage-R...al_Components_Supplies_ET&hash=item5ae9b25ed8

 

My biggest concern is heat, because whatever is powering my 5 devices will be under my fabric car seat resting on fabric carpet, sometimes in 100+ degrees summer weather. Thats why I'm thinking of going with the above options. My other option was to just use a huge 6V lead acid, but since I can't discharge past 6.0V, and I need 5-6V, that kind of kills that idea. Sucks, cause a straight up battery with no circuitry would be awesome.

 

Keep in mind that even though it can take 5V instead of 6v, running it at 5V would probably draw a little more current.... It may be negligible, but if you are running at close to max spec, it becomes important. For that reason alone, i would cross off the first one.

 

Why would you start a new thread? Your other thread was sufficient.

I evaluated your options in the other thread.

Maybe this is another personality of Split Infinity.

 

My biggest concern is heat, because whatever is powering my 5 devices will be under my fabric car seat resting on fabric carpet, sometimes in 100+ degrees summer weather. Thats why I'm thinking of going with the above options. My other option was to just use a huge 6V lead acid, but since I can't discharge past 6.0V, and I need 5-6V, that kind of kills that idea. Sucks, cause a straight up battery with no circuitry would be awesome.

So its an automotive project then?

 

@ gregthegeek

Since you brought up the automotive facet of your project, you should now explain very carefully the following topics:

1. How are you planning to tap to the 12V power source?
2. What kind of devices are you going to power
3. What will their purpose be?

Your answers can keep this thread alive, since, as you may know, automotive modifications aren't allowed in AAC.

 

My project is standalone and unrelated to anything automotive. For all intents and purposes, my project could be put inside a NASA spaceship or in my basement. It's standalone and does not involve my vehicle in any way whatsoever, except that it will be "sitting in my car" on fabric carpet, under a fabric car seat. No different than if it was sitting on my living room carpet with a pillow over it. Heat and fire hazard are something I need to keep in mind.

1.) The 12V source will be a very large 12V sealed lead-acid battery (possibly as much as 100aH). In no way whatsoever will this be connected to my vehicle. This project is to isolate my devices from my car's electrical system.
2.) The devices I am powering are basically walkie-talkies. Specifically, police scanners that I use for my job in the tv news industry. They are perfectly legal.
3.) The purpose of my project is to power 5 police scanners that have 4 AA batteries each. Instead of replacing 20 AA batteries every day, I want to have one large battery that can last me several days (7-10 ideally). The output wiring from my project will go straight in to the battery compartment of each police scanner, mimicking 4 AA batteries.

Thanks

 

@ gregthegeek,

You have started 4 different threads for the same project. This not only clutters the forum, but most importantly makes it very difficult for the other members to help you effectively.

All threads will be closed, except for the original one. Please continue the discussion there.
Do not open another thread for the same project.

The threads were not merged, as it would cause confusion from the overlapping answers.