convert 12V DC to 9V DC

[asn-naso]

If I wanted to pull power from my fans in my hood (12VDC), and convert it down to 9VDC, is there a simple and safe way to do it?

 

[sethsolomon]

You need a step down transformer.

http://www.amazon.com/HOSSEN®-Converter-Supply-Module-Non-isolated/dp/B00A71E52G

 

[asn-naso]

How safe are they, and any place local that may carry them?

 

[asn-naso]

What about something like this?

http://www.radioshack.com/product/index.jsp?productId=2062599&retainProdsInSession=1

It would drop the 12V down to 5V, which I would then send to a 10K Ohm Linear Potentiometer, then on to my driver. 5V at max should be ok, as the CREE's are only inches above the water in the nano, but will the standard 10K Ohm pot will work if it only has 5V going into it, instead of 10V?

 

[sethsolomon]

Whats the amperage of the transformer?

 

[asn-naso]

12V 500 mA is the one I am using to drive my fans. If possible, without adding too much heat I'd like to pull from that, and run it to a 10K Ohm Potentiometer, to dim my LEDs.

If I can't do that, can I take a 5V Cell phone charger, and run that through the 10K Ohm Potentiometer? Or does it need to be a 10V power supply?

 

[HondaHound]

My dimmable driver takes 0V-10V on the dimming circuit to operate. I believe 5V going through a linear pot would work for a dimmer.

 

[sethsolomon]

Just use this: http://www.walmart.com/ip/CyberPowe...V-12V-1300mA-and-AC-Power-Plug-Black/30253322

you can just hot switch the voltage. and just wire the fans in parallel. Make it easy on yourself.

 

[asn-naso]

But the fans need 12V, and if I only give them 10V, they won't spin as fast, and won't cool as well. If I give the fans 12V, then the meanwell driver will have 120% of what it was designed for.

 

[Luke.Fraizer]

I picked up a variable voltage plug in from radio shack to put in computer fans in a Vivarium I built several years ago. You may want to look into that. It allows 2v to 12v