Fluorescent Tube and Switching Ballast notes

Tube nomenclature

What does F40T12CW/IS mean? F30T8 RS ?

ANSI C82. 1, C82.1 1, C82.2 and C82.3. These standards are the basis for the Certified Ballast Manufacturers certification program. C82.1 covers electromagnetic ballast performance and C82.11 covers electronic ballast performance.

Ballast standards

These ballast standards include reference to portions of the ANSI C78 series of specifications for fluorescent lamps. These lamp standards provide the critical electrical and physical characteristics for each lamp type. A different C78 specification is written for each lamp type and the CBM Certified ballast must meet the electrical requirements as specified by the appropriate section of C82.1 or C82.11 and the C78 series.

I bought and read these - typical ANSI stuff - little content repeated constantly.

The meat and Potatoes

There are the standard output tubes, HO for High Output, and VHO, for Very High Output. The higher output tubes use different connectors. A VHO 48" lamp runs at 109W.

Your typical 40W 48" tube is supposed to run at 0.43A., start at 400 - 650 V and have about a 93V working voltage.

HO's run at 1.0A and VHO run at 1.5A

Your magnetic ballast is a crude ac current regulator - makes noise, works poorly over temperature changes, and produces a flicking light. The newer electronic ballasts were greatly delayed getting to to the market place by a spider web of patents. After the lawyes sucked away most of the profit this mess of patents and regulations are still keeping the price higher than it should be. They added a new a power factor specification that makes them a bit more pricey. They run at a high frequency so the light doesn't flicker and the tubes work more efficiently in the kHz range. The bulbs also last longer and they can be dimmed by lowering the regulated current. Most of these are made for the 33W 48" tubes in a T8 package (1") that put out almost as much light as a 40W lamp.

The Power factor is corrected by having a boost circuit in the regulating circuit that keeps the ballast drawing power over the entire cycle and not just at the ac wave form crests.

IR remotes and IRDATA interference

Some of the ballast interfered with IR control equipment which have a carrier frequency's of 32.75, 36, 36.7, 38, 40 and 50 kHz.. Now that the ballasts are running at 100kHz (1999) we have the new IRDATA specification that negotiates at about that frequency. Hopefully at 100Khz the mercury gas will stay ionized constantly enough that they won't interfere. I read someplace that 400Khz is the best frequency for efficiency of the tubes - may not be practical for many reasons (RF, supply efficiency etc.)

The quest is to make CHEAP ballasts that work well - one way is to use a small supply cap so that some of the 60 hz AC wave form slips through and the thing starts to make noise again. The patent processes is full of notes on this. One of the problems is to have a high starting voltage that won't reverse couple the tubes capacitance to the primary when the bulb starts and kill the driving transistors. One way is to use saturating magnetics to form a switch.

Once you have a current regulator it is a simple trick to make that current adjustable. Then you have a dimmable light.

Olek nilssen is Mr. ballast patent

Other things from my notes - there are tubes that run at 0.265A and 0.8A if anyone knows their designations I would appreciate.


With permission form Jeffrey Meade Saturday, October 26, 2002 :

48" 40 watt lamps have been replaced with 34-watt lamps. EPA and tube manufacturers have reduced the mercury content in tubes. This makes a lamp less efficient. Less mercury makes it harder to start a tube. A tube must be 1/2" or less from a true metal ground, the length of the tube, to ignite the tube. Each end has a low voltage filament. High voltage is applied to the two ends of a tube. The ignition starts at both ends of a tube, by capacitively coupling with said ground and traveling toward the middle. A new tube will swirl or pulse for a few moments. If a new tube won't ignite, swing it around or rub it with a cloth. If one end of a tube is cold, then that filament is bad, or the ballast is bad, or that socket is bad, or a wire connection to that socket is bad. If one end of a tube is cold, rotate the tube to test whether the filament is okay. So far, residential lamps may be disposed of without penalty. Commercial tubes must be recycled. It costs more to recycle than to buy a tube. A business may recycle their tubes. If a commercial tube is accidentally broken, it may be disposed of without recycling. I wish they would increase the mercury content in a tube to the old standard, and require each spent tube to be recycled. --


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