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How to power various DC devices from closet cleanly

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mklein

New Member
I already have a 12v? rack-mount cctv power supply.

Some serial LCDs which I need to drive from wiring closet offer 'high' voltage option and will run from 9-15vdc. So this should work on cctv power supply unit.

But I have some devices like an iButton reader w/led that takes 2.7vdc and short of moving my bench power supply down into closet to dial in right voltage...how best is this done?

My cctv power supply wouldn't be appropriate correct?

I'm looking for something that could drive 'n' devices also.


thanks in advance.

mike
 
Last edited:

tralfam

New Member
I already have a 12v? rack-mount cctv power supply.

Some serial LCDs which I need to drive from wiring closet offer 'high' voltage option and will run from 9-15vdc. So this should work on cctv power supply unit.

But I have some devices like an iButton reader w/led that takes 2.7vdc and short of moving my bench power supply down into closet to dial in right voltage...how best is this done?

My cctv power supply wouldn't be appropriate correct?

I'm looking for something that could drive 'n' devices also.


thanks in advance.

mike
I am confused about what exactly you are asking, but I think you just need a resistor for the button's led.
 

mklein

New Member
Ok, so for any dc device I want to power from 12vdc cctv rack power supply...I can merely insert resistor (appropriate one) to bring voltage down to 2.7vdc.

I should do this on + side of power on cctv power supply or does it matter.

I think this reference explains it well...thanks for help.

resistors
 
Last edited:

tralfam

New Member
Ok, so for any dc device I want to power from 12vdc cctv rack power supply...I can merely insert resistor (appropriate one) to bring voltage down to 2.7vdc.

I should do this on + side of power on cctv power supply or does it matter.

I think this reference explains it well...thanks for help.

resistors
Basically, that is the how you can power your led. You just need to calculate the right resistor for whatever you are trying to run off it.
 

Leftyretro

New Member
A better option would be to use a voltage regulator to change the 12vdc input to the 2.7 vdc output for your device. A resistor will only drop the correct voltage at one specific current draw and many devices vary the current they draw depending on what they are doing at any specific time.

Lefty
 
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