Hi,
I am new to this forum hopefully yall can help me out. I am going to attempt to convert a 40watt 4 foot fluorescent light bulb to dc power. I am going to go with a DC ballast for the light. Im looking at the
PST-EB40S12 ballast on the site http://www.powerstream.com/ballast-1.htm ... Now all tha i need is a proper power supply. Of course I was going to use a battery. Which i might later. But for now im looking at getting a AC-DC wall power supply. According to the powerstream.com site, the specs for the proper ballast needs an input voltage of 10-15 VDC and input current of 1.8-2.2 Amps. What would be a proper power supply for this. I have looked and looked for it and found one that was close but the amps were higher than the specified amps. Is this ok? The reason im going DC is that im going to use this light as a fish attractant near water so to be safe im trying to convert it to DC power. Any help would be greatly appreciated!!!! Thanks!

Travis

 

While I can't help you, I remember reading how the WWII submarines did this. They used a resistor as a ballast. It got hot (which is why AC used a ballast coil), so they bolted it to the skin of the submarine to dissipate the heat. Basically you need a starter, which causes the filaments on each end to heat up (like a light bulb). This ionizes the gas inside, so when you disconnect the power to the filaments and put the bulk of the voltage across the tube, causing it to glow. The resistor (or ballast) restricts the current through the device. Since the ballast is reactive it is extremely efficient, while the resistor is really inefficient.

Reading through your device it is a SMPS constant current source, which is much more efficient.

 

Interesting... I remember hearing of submarine ballasts, just didnt know about the heating up factor. Well maybe someone else will be able to help! Thanks for the quick reply!

 

We've had similar posts about using LEDs for the same purpose.

 

You can go to an RV store and find fluorescent lamps that run on 12 V. That might not be as fun as rolling your own, but I'm pretty sure it will be less work. I put one in our RV about a decade ago -- my wife found it at a second hand store for a few bucks (it was new). It has worked great for us.

 

If you want to check out LEDs, here is a similar project.

How to connect 50 Leds

 

A power supply with a higher A rating than the 40W lamp requires is no problem, just possibly a small bit more power loss.