[Top] [All Lists]

Re: [Shop-talk] tube fluorescent wattage

Subject: Re: [Shop-talk] tube fluorescent wattage
From: Doug Braun <>
Date: Sun, 1 Mar 2009 09:21:51 -0800 (PST)
One of the things I read a few days ago about fluorescent bulbs said that some 
"Energy-saving" bulbs use less power, but their light output is lower, too, and 
the lumens-per-watt is often worse than regular bulbs.

And isn't the main job of a ballast to control the amount of current(and power 
delivered to the bulb?  So you could make an "energy saving" ballast that is no 
more efficient than a regular one- it just sends less current to the bulb, 
giving you less light output.

One other thing that occurred to me:  How can you easily measure now much power 
a fluorescent bulb is consuming, not counting the ballast? It's easy for an 
incandescent bulb: it is a pure resistive load and you simply have to measure 
the RMS current and voltage.  But the voltage and current of a fluorescent lamp 
probably have a complex waveform and phase relationship, and you would need 
laboratory-style instrumentation to accurately measure the true power.

And measuring a complete bulb+ballast fixture with a Kill-a-Watt style meter 
may not be very accurate because of the power factor of a magnetic ballast, and 
non linearity of an electronic one.

Support Team.Net

Shop-talk mailing list

<Prev in Thread] Current Thread [Next in Thread>