Non-saber related electronics question

[TimeRender]

Hey all. I recently purchased a kit for building a nixie tube clock. The assembled kit has three voltage test points; one for the ground, one at 5v and one at 170v. I contacted the manufacturer and asked whether it would be possible to use the 5v test point as a power supply for accessory LEDs and asked him what current would be safe to draw from that point. He told me this was ok but that I shouldn't try to draw more than 60ma. This was just fine because I was planning on using a few LEDs with a forward voltage of 3.6v at 25ma, requiring nothing more than the correct resistor. Easy.

However, after talking to the manufacturer I decided it might be more interesting to use the 5v point to power a few cold cathode tubes. These tubes require 12v at 5ma. I tracked down a DC-DC step-up board that should be fine for providing the necessary voltage. I'll post the link below. However, I need to be sure that the step-up board won't draw more than the clock manufacturer's suggested 60ma. It is my understanding that a step-up board essentially converts an increase in drawn current into an increase in voltage. Does anyone here have experience with these things? Would you be able to tell me if my understanding is correct? Is there a formula for calculating the current that will be drawn? Any help would be greatly appreciated.

http://cgi.ebay.com/2PCS-1V-5V-12V-D...item4aaba3ae0a

Edit: Feel free to chime in also if you have a better alternative than this. I'm open to suggestions.

[Sunrider]

I would estimate the converter is 60% efficient. At 2.5 times the the voltage, 5ma at 12v would be something like 20-25ma at 5v.

[TimeRender]

Well it says it is 80% efficient, but it comes from Hong Kong so 60% is probably a bit closer to the truth. What is the formula for calculating the conversion from current to voltage?

[(null).exe]

Slothfurnace is somewhat of a Nixie Guru, so I'm sure he'll see this, or you can PM/Shoutbox him and ask about it.

http://slothfurnace.com/sabers/NixieClocks_01.html

^--------------- Read it, it's good for you

[TimeRender]

Thanks for the help guys!