7/30/2019 How Does a Fluorescent Starter Work

1/4

How does a fluorescent starter work?Afluorescent lightdoes not have the usual glowing filament of anincandescent bulb, but instead contains

a mercury vaporthat gives off ultraviolet light when ionized. The ultraviolet light makes particles that

coat the inside of the tube, and these particles glow or fluoresce (seeHow Fluorescent Lamps Workfor

details).

Fluorescent starters are used inseveral typesof fluorescent lights. The starter is there to help the lamplight. Whenvoltageis applied to the fluorescent lamp, here's what happens:

1. The starter (which is simply a timed switch) allows current to flow through the filaments at the

ends of the tube.

2. The current causes the starter's contacts to heat up and open, thus interrupting the flow of

current. The tube lights.

3. Since the lighted fluorescent tube has a low resistance, the ballast now serves as a current

limiter.

When you turn on a fluorescent tube, the starter is a closed switch. The filaments at the ends of the tube

are heated by electricity, and they create a cloud of electrons inside the tube. The fluorescent starter is a

time-delay switch that opens after a second or two. When it opens, the voltage across the tube allows a

stream of electrons to flow across the tube and ionize the mercury vapor.

Without the starter, a steady stream of electrons is never created between the two filaments, and the

lamp flickers. Without the ballast, the arc is a short circuit between the filaments, and this short circuit

contains a lot of current. The current either vaporizes the filaments or causes the bulb to explode.

According toSam's F-Lamp FAQ:

The most common fluorescent starter is called a "glow tube starter" (or just starter) and contains asmall gas (neon, etc.) filled tube and an optional radio frequency interference (RFI) suppressioncapacitor in a cylindrical aluminum can with a 2 pin base. While all starters are physicallyinterchangeable, the wattage rating of the starter should be matched to the wattage rating of thefluorescent tubes for reliable operation and long life.

The glow tube incorporates a switch which is normally open. When power is applied, a glow discharge

takes place which heats a bimetal contact. A second or so later, the contacts close and provide current to

the fluorescent filaments. Since the glow is extinguished, there is no longer any heating of the bimetal and

the contacts open. The inductive kick generated at the instant of opening triggers the main discharge in

the fluorescent tube. If the contacts open at a bad time, there isn't enough inductive kick and the process

repeats.

http://home.howstuffworks.com/fluorescent-lamp.htmhttp://home.howstuffworks.com/fluorescent-lamp.htmhttp://home.howstuffworks.com/fluorescent-lamp.htmhttp://home.howstuffworks.com/light-bulb.htmhttp://home.howstuffworks.com/light-bulb.htmhttp://home.howstuffworks.com/light-bulb.htmhttp://home.howstuffworks.com/fluorescent-lamp.htmhttp://home.howstuffworks.com/fluorescent-lamp.htmhttp://home.howstuffworks.com/fluorescent-lamp.htmhttp://howstuffworks.com/framed.htm?parent=question337.htm&url=http://www.misty.com/%7Edon/f-lamp.html#wd5http://howstuffworks.com/framed.htm?parent=question337.htm&url=http://www.misty.com/%7Edon/f-lamp.html#wd5http://howstuffworks.com/framed.htm?parent=question337.htm&url=http://www.misty.com/%7Edon/f-lamp.html#wd5http://home.howstuffworks.com/question501.htmhttp://home.howstuffworks.com/question501.htmhttp://home.howstuffworks.com/question501.htmhttp://home.howstuffworks.com/framed.htm?parent=question337.htm&url=http://www.misty.com/%7Edon/f-lamp.htmlhttp://home.howstuffworks.com/framed.htm?parent=question337.htm&url=http://www.misty.com/%7Edon/f-lamp.htmlhttp://home.howstuffworks.com/framed.htm?parent=question337.htm&url=http://www.misty.com/%7Edon/f-lamp.htmlhttp://stat.dealtime.com/DealFrame/DealFrame.cmp?bm=882&BEFID=96650&aon=891^891&MerchantID=432889&crawler_id=432889&dealId=RylqUhepa8r5sHDqlhY2uA==&url=http://www.1000bulbs.com/38626/?utm_source=SmartFeedShoppingcom&utm_medium=Shopping&utm_term=CFTR26WGX24q827NAED2087926Watt4PinGX24q3Base2700KCompactFluorescentCFLLightBulb&utm_content=CFTR26WGX24q827NAED2087926Watt4PinGX24q3Base2700KCompactFluorescentCFLLightBulb&utm_campaign=SmartFeedShoppingcom&site=www.shopping.com&linkin_id=8044909&searchID=p8.53002526dfe03de95e06&DealName=CFTR26W/GX24q/827+-+NAED+20879+-+26+Watt+-+4+Pin+GX24q-3+Base+-+2700K+-+Com...&dlprc=2.27&crn=USD&istrsmrc=0&isathrsl=0&AR=1&NG=5&NDP=&PN=1&ST=7&DB=sdcprod&MT=phx-pmt3-1&FPT=DSP&NDS=&NMS=&MRS=&PD=&brnId=14305&IsFtr=1&IsSmart=0&DMT=1000&op=&CM=&DlLng=&RR=&cid=&semid1=&semid2=&IsLps=&CC=&SL=&FS=&code=&acode=&category=&HasLink=&frameId=&ND=&MN=&PT=&prjID=&GR=&lnkId=&VK=http://stat.dealtime.com/DealFrame/DealFrame.cmp?bm=882&BEFID=96650&aon=891^891&MerchantID=432889&crawler_id=432889&dealId=RylqUhepa8r5sHDqlhY2uA==&url=http://www.1000bulbs.com/38626/?utm_source=SmartFeedShoppingcom&utm_medium=Shopping&utm_term=CFTR26WGX24q827NAED2087926Watt4PinGX24q3Base2700KCompactFluorescentCFLLightBulb&utm_content=CFTR26WGX24q827NAED2087926Watt4PinGX24q3Base2700KCompactFluorescentCFLLightBulb&utm_campaign=SmartFeedShoppingcom&site=www.shopping.com&linkin_id=8044909&searchID=p8.53002526dfe03de95e06&DealName=CFTR26W/GX24q/827+-+NAED+20879+-+26+Watt+-+4+Pin+GX24q-3+Base+-+2700K+-+Com...&dlprc=2.27&crn=USD&istrsmrc=0&isathrsl=0&AR=1&NG=5&NDP=&PN=1&ST=7&DB=sdcprod&MT=phx-pmt3-1&FPT=DSP&NDS=&NMS=&MRS=&PD=&brnId=14305&IsFtr=1&IsSmart=0&DMT=1000&op=&CM=&DlLng=&RR=&cid=&semid1=&semid2=&IsLps=&CC=&SL=&FS=&code=&acode=&category=&HasLink=&frameId=&ND=&MN=&PT=&prjID=&GR=&lnkId=&VK=http://home.howstuffworks.com/framed.htm?parent=question337.htm&url=http://www.misty.com/%7Edon/f-lamp.htmlhttp://home.howstuffworks.com/question501.htmhttp://howstuffworks.com/framed.htm?parent=question337.htm&url=http://www.misty.com/%7Edon/f-lamp.html#wd5http://home.howstuffworks.com/fluorescent-lamp.htmhttp://home.howstuffworks.com/light-bulb.htmhttp://home.howstuffworks.com/fluorescent-lamp.htm

7/30/2019 How Does a Fluorescent Starter Work

2/4

CFTR26W/GX24q/827 - NAED 20879 - 26 Watt - 4 Pin GX24q-3 Base - 2700K - Com...Plusrite - F02623416201 - PL26W/3U/4P/827 - 4-Pin Triple Tube Plug In CFL - 26 Watt - GX24q-3 - 2700K - 5.28 in.

$2.27

22 WATT Circline Fluorescent Light BulbsA 22 Watt T9 circline fluorescent light bulb in cool and warm white from Pegasus Associates Lighting.

$3.75

GE 26w FLE26 PAR38 XL compact fluorescent light bulb

FLE26/2/PAR38/XL FREE SHIPPING on ORDERS OVER $100.00.

What is the difference between a fluorescent light anda neon light?

Noel Hendrickson/Photographers Choice RF/Getty ImagesMany offices are lit with fluorescent lamps.

A neon light is the sort of light you see used in advertising signs. These signs are made of long, narrow

glass tubes, and these tubes are often bent into all sorts of shapes. The tube of a neon light can spell out

a word, for example. These tubes emit light in different colors.

A fluorescent light, on the other hand, is most often a long, straight tube that produces white light. You

see fluorescent lights in offices, stores and some home fixtures.

The idea behind a neon light is simple. Inside the glass tube there is a gas like neon, argon or krypton at

low pressure. At both ends of the tube there are metal electrodes. When you apply a high voltage to the

electrodes, the neon gas ionizes, and electrons flow through the gas. These electrons excite the neon

atomsand cause them to emit light that we can see. Neon emits red light when energized in this way.

Other gases emit other colors.

A fluorescent light works on a similar idea but it has an extra step. Inside a fluorescent lightis low-

pressure mercury vapor. When ionized, mercury vapor emits ultraviolet light.Human eyesare not

sensitive to ultraviolet light (although human skin is -- seeHow Sunburns and Sun Tans Work!).

Therefore, the inside of a fluorescent light is coated with a phosphor. A phosphor is a substance that can

http://stat.dealtime.com/DealFrame/DealFrame.cmp?bm=882&BEFID=96650&aon=891%5E891&MerchantID=432889&crawler_id=432889&dealId=RylqUhepa8r5sHDqlhY2uA%3D%3D&url=http%3A%2F%2Fwww.1000bulbs.com%2F38626%2F%3Futm_source%3DSmartFeedShoppingcom%26utm_medium%3DShopping%26utm_term%3DCFTR26WGX24q827NAED2087926Watt4PinGX24q3Base2700KCompactFluorescentCFLLightBulb%26utm_content%3DCFTR26WGX24q827NAED2087926Watt4PinGX24q3Base2700KCompactFluorescentCFLLightBulb%26utm_campaign%3DSmartFeedShoppingcom%26site%3Dwww.shopping.com&linkin_id=8044909&searchID=p8.53002526dfe03de95e06&DealName=CFTR26W%2FGX24q%2F827+-+NAED+20879+-+26+Watt+-+4+Pin+GX24q-3+Base+-+2700K+-+Com...&dlprc=2.27&crn=USD&istrsmrc=0&isathrsl=0&AR=1&NG=5&NDP=&PN=1&ST=7&DB=sdcprod&MT=phx-pmt3-1&FPT=DSP&NDS=&NMS=&MRS=&PD=&brnId=14305&IsFtr=1&IsSmart=0&DMT=1000&op=&CM=&DlLng=&RR=&cid=&semid1=&semid2=&IsLps=&CC=&SL=&FS=&code=&acode=&category=&HasLink=&frameId=&ND=&MN=&PT=&prjID=&GR=&lnkId=&VK=http://stat.dealtime.com/DealFrame/DealFrame.cmp?bm=527&BEFID=96650&aon=518%5E518&MerchantID=478516&crawler_id=478516&dealId=NI8D1c7s7uZebe_yf7BojQ%3D%3D&url=http%3A%2F%2Fwww.pegasusassociates.com%2FFluorescentCeiling-P7008.html%3Futm_source%3Dshopping-com%26utm_medium%3Dcpc%26utm_term%3DFC8T9-xW%26utm_campaign%3Dshopping-com&linkin_id=8044909&searchID=p8.53002526dfe03de95e06&DealName=22+WATT+Circline+Fluorescent+Light+Bulbs&dlprc=3.75&crn=USD&istrsmrc=0&isathrsl=0&AR=2&NG=5&NDP=&PN=1&ST=7&DB=sdcprod&MT=phx-pmt3-1&FPT=DSP&NDS=&NMS=&MRS=&PD=&brnId=14305&IsFtr=1&IsSmart=0&DMT=1000&op=&CM=&DlLng=&RR=&cid=&semid1=&semid2=&IsLps=&CC=&SL=&FS=&code=&acode=&category=&HasLink=&frameId=&ND=&MN=&PT=&prjID=&GR=&lnkId=&VK=http://stat.dealtime.com/DealFrame/DealFrame.cmp?bm=541&BEFID=96650&aon=532%5E532&MerchantID=308534&crawler_id=308534&dealId=SFwBVmyWePjQdzXRrk_qSQ%3D%3D&url=http%3A%2F%2Fwww.bulbamerica.com%2FGE-26w-FLE26-PAR38-XL-compact-fluorescent-light-bulb-4433-prod.htm%3Fdfc%3DMw%3D%3D&linkin_id=8044909&searchID=p8.53002526dfe03de95e06&DealName=GE+26w+FLE26+PAR38+XL+compact+fluorescent+light+bulb&dlprc=13.18&crn=USD&istrsmrc=0&isathrsl=0&AR=3&NG=5&NDP=&PN=1&ST=7&DB=sdcprod&MT=phx-pmt3-1&FPT=DSP&NDS=&NMS=&MRS=&PD=&brnId=14305&IsFtr=1&IsSmart=0&DMT=1000&op=&CM=&DlLng=&RR=&cid=&semid1=&semid2=&IsLps=&CC=&SL=&FS=&code=&acode=&category=&HasLink=&frameId=&ND=&MN=&PT=&prjID=&GR=&lnkId=&VK=http://howstuffworks.com/framed.htm?parent=question293.htm&url=http://www.gettyimages.comhttp://howstuffworks.com/framed.htm?parent=question293.htm&url=http://www.gettyimages.comhttp://howstuffworks.com/framed.htm?parent=question293.htm&url=http://www.gettyimages.comhttp://home.howstuffworks.com/atom.htmhttp://home.howstuffworks.com/atom.htmhttp://home.howstuffworks.com/fluorescent-lamp.htmhttp://home.howstuffworks.com/fluorescent-lamp.htmhttp://home.howstuffworks.com/fluorescent-lamp.htmhttp://home.howstuffworks.com/eye.htmhttp://home.howstuffworks.com/eye.htmhttp://home.howstuffworks.com/eye.htmhttp://home.howstuffworks.com/sunscreen.htmhttp://home.howstuffworks.com/sunscreen.htmhttp://home.howstuffworks.com/sunscreen.htmhttp://stat.dealtime.com/DealFrame/DealFrame.cmp?bm=541&BEFID=96650&aon=532^532&MerchantID=308534&crawler_id=308534&dealId=SFwBVmyWePjQdzXRrk_qSQ==&url=http://www.bulbamerica.com/GE-26w-FLE26-PAR38-XL-compact-fluorescent-light-bulb-4433-prod.htm?dfc=Mw==&linkin_id=8044909&searchID=p8.53002526dfe03de95e06&DealName=GE+26w+FLE26+PAR38+XL+compact+fluorescent+light+bulb&dlprc=13.18&crn=USD&istrsmrc=0&isathrsl=0&AR=3&NG=5&NDP=&PN=1&ST=7&DB=sdcprod&MT=phx-pmt3-1&FPT=DSP&NDS=&NMS=&MRS=&PD=&brnId=14305&IsFtr=1&IsSmart=0&DMT=1000&op=&CM=&DlLng=&RR=&cid=&semid1=&semid2=&IsLps=&CC=&SL=&FS=&code=&acode=&category=&HasLink=&frameId=&ND=&MN=&PT=&prjID=&GR=&lnkId=&VK=http://stat.dealtime.com/DealFrame/DealFrame.cmp?bm=527&BEFID=96650&aon=518^518&MerchantID=478516&crawler_id=478516&dealId=NI8D1c7s7uZebe_yf7BojQ==&url=http://www.pegasusassociates.com/FluorescentCeiling-P7008.html?utm_source=shopping-com&utm_medium=cpc&utm_term=FC8T9-xW&utm_campaign=shopping-com&linkin_id=8044909&searchID=p8.53002526dfe03de95e06&DealName=22+WATT+Circline+Fluorescent+Light+Bulbs&dlprc=3.75&crn=USD&istrsmrc=0&isathrsl=0&AR=2&NG=5&NDP=&PN=1&ST=7&DB=sdcprod&MT=phx-pmt3-1&FPT=DSP&NDS=&NMS=&MRS=&PD=&brnId=14305&IsFtr=1&IsSmart=0&DMT=1000&op=&CM=&DlLng=&RR=&cid=&semid1=&semid2=&IsLps=&CC=&SL=&FS=&code=&acode=&category=&HasLink=&frameId=&ND=&MN=&PT=&prjID=&GR=&lnkId=&VK=http://stat.dealtime.com/DealFrame/DealFrame.cmp?bm=541&BEFID=96650&aon=532^532&MerchantID=308534&crawler_id=308534&dealId=SFwBVmyWePjQdzXRrk_qSQ==&url=http://www.bulbamerica.com/GE-26w-FLE26-PAR38-XL-compact-fluorescent-light-bulb-4433-prod.htm?dfc=Mw==&linkin_id=8044909&searchID=p8.53002526dfe03de95e06&DealName=GE+26w+FLE26+PAR38+XL+compact+fluorescent+light+bulb&dlprc=13.18&crn=USD&istrsmrc=0&isathrsl=0&AR=3&NG=5&NDP=&PN=1&ST=7&DB=sdcprod&MT=phx-pmt3-1&FPT=DSP&NDS=&NMS=&MRS=&PD=&brnId=14305&IsFtr=1&IsSmart=0&DMT=1000&op=&CM=&DlLng=&RR=&cid=&semid1=&semid2=&IsLps=&CC=&SL=&FS=&code=&acode=&category=&HasLink=&frameId=&ND=&MN=&PT=&prjID=&GR=&lnkId=&VK=http://stat.dealtime.com/DealFrame/DealFrame.cmp?bm=527&BEFID=96650&aon=518^518&MerchantID=478516&crawler_id=478516&dealId=NI8D1c7s7uZebe_yf7BojQ==&url=http://www.pegasusassociates.com/FluorescentCeiling-P7008.html?utm_source=shopping-com&utm_medium=cpc&utm_term=FC8T9-xW&utm_campaign=shopping-com&linkin_id=8044909&searchID=p8.53002526dfe03de95e06&DealName=22+WATT+Circline+Fluorescent+Light+Bulbs&dlprc=3.75&crn=USD&istrsmrc=0&isathrsl=0&AR=2&NG=5&NDP=&PN=1&ST=7&DB=sdcprod&MT=phx-pmt3-1&FPT=DSP&NDS=&NMS=&MRS=&PD=&brnId=14305&IsFtr=1&IsSmart=0&DMT=1000&op=&CM=&DlLng=&RR=&cid=&semid1=&semid2=&IsLps=&CC=&SL=&FS=&code=&acode=&category=&HasLink=&frameId=&ND=&MN=&PT=&prjID=&GR=&lnkId=&VK=http://stat.dealtime.com/DealFrame/DealFrame.cmp?bm=541&BEFID=96650&aon=532^532&MerchantID=308534&crawler_id=308534&dealId=SFwBVmyWePjQdzXRrk_qSQ==&url=http://www.bulbamerica.com/GE-26w-FLE26-PAR38-XL-compact-fluorescent-light-bulb-4433-prod.htm?dfc=Mw==&linkin_id=8044909&searchID=p8.53002526dfe03de95e06&DealName=GE+26w+FLE26+PAR38+XL+compact+fluorescent+light+bulb&dlprc=13.18&crn=USD&istrsmrc=0&isathrsl=0&AR=3&NG=5&NDP=&PN=1&ST=7&DB=sdcprod&MT=phx-pmt3-1&FPT=DSP&NDS=&NMS=&MRS=&PD=&brnId=14305&IsFtr=1&IsSmart=0&DMT=1000&op=&CM=&DlLng=&RR=&cid=&semid1=&semid2=&IsLps=&CC=&SL=&FS=&code=&acode=&category=&HasLink=&frameId=&ND=&MN=&PT=&prjID=&GR=&lnkId=&VK=http://stat.dealtime.com/DealFrame/DealFrame.cmp?bm=527&BEFID=96650&aon=518^518&MerchantID=478516&crawler_id=478516&dealId=NI8D1c7s7uZebe_yf7BojQ==&url=http://www.pegasusassociates.com/FluorescentCeiling-P7008.html?utm_source=shopping-com&utm_medium=cpc&utm_term=FC8T9-xW&utm_campaign=shopping-com&linkin_id=8044909&searchID=p8.53002526dfe03de95e06&DealName=22+WATT+Circline+Fluorescent+Light+Bulbs&dlprc=3.75&crn=USD&istrsmrc=0&isathrsl=0&AR=2&NG=5&NDP=&PN=1&ST=7&DB=sdcprod&MT=phx-pmt3-1&FPT=DSP&NDS=&NMS=&MRS=&PD=&brnId=14305&IsFtr=1&IsSmart=0&DMT=1000&op=&CM=&DlLng=&RR=&cid=&semid1=&semid2=&IsLps=&CC=&SL=&FS=&code=&acode=&category=&HasLink=&frameId=&ND=&MN=&PT=&prjID=&GR=&lnkId=&VK=http://home.howstuffworks.com/sunscreen.htmhttp://home.howstuffworks.com/eye.htmhttp://home.howstuffworks.com/fluorescent-lamp.htmhttp://home.howstuffworks.com/atom.htmhttp://howstuffworks.com/framed.htm?parent=question293.htm&url=http://www.gettyimages.comhttp://stat.dealtime.com/DealFrame/DealFrame.cmp?bm=541&BEFID=96650&aon=532%5E532&MerchantID=308534&crawler_id=308534&dealId=SFwBVmyWePjQdzXRrk_qSQ%3D%3D&url=http%3A%2F%2Fwww.bulbamerica.com%2FGE-26w-FLE26-PAR38-XL-compact-fluorescent-light-bulb-4433-prod.htm%3Fdfc%3DMw%3D%3D&linkin_id=8044909&searchID=p8.53002526dfe03de95e06&DealName=GE+26w+FLE26+PAR38+XL+compact+fluorescent+light+bulb&dlprc=13.18&crn=USD&istrsmrc=0&isathrsl=0&AR=3&NG=5&NDP=&PN=1&ST=7&DB=sdcprod&MT=phx-pmt3-1&FPT=DSP&NDS=&NMS=&MRS=&PD=&brnId=14305&IsFtr=1&IsSmart=0&DMT=1000&op=&CM=&DlLng=&RR=&cid=&semid1=&semid2=&IsLps=&CC=&SL=&FS=&code=&acode=&category=&HasLink=&frameId=&ND=&MN=&PT=&prjID=&GR=&lnkId=&VK=http://stat.dealtime.com/DealFrame/DealFrame.cmp?bm=527&BEFID=96650&aon=518%5E518&MerchantID=478516&crawler_id=478516&dealId=NI8D1c7s7uZebe_yf7BojQ%3D%3D&url=http%3A%2F%2Fwww.pegasusassociates.com%2FFluorescentCeiling-P7008.html%3Futm_source%3Dshopping-com%26utm_medium%3Dcpc%26utm_term%3DFC8T9-xW%26utm_campaign%3Dshopping-com&linkin_id=8044909&searchID=p8.53002526dfe03de95e06&DealName=22+WATT+Circline+Fluorescent+Light+Bulbs&dlprc=3.75&crn=USD&istrsmrc=0&isathrsl=0&AR=2&NG=5&NDP=&PN=1&ST=7&DB=sdcprod&MT=phx-pmt3-1&FPT=DSP&NDS=&NMS=&MRS=&PD=&brnId=14305&IsFtr=1&IsSmart=0&DMT=1000&op=&CM=&DlLng=&RR=&cid=&semid1=&semid2=&IsLps=&CC=&SL=&FS=&code=&acode=&category=&HasLink=&frameId=&ND=&MN=&PT=&prjID=&GR=&lnkId=&VK=http://stat.dealtime.com/DealFrame/DealFrame.cmp?bm=882&BEFID=96650&aon=891%5E891&MerchantID=432889&crawler_id=432889&dealId=RylqUhepa8r5sHDqlhY2uA%3D%3D&url=http%3A%2F%2Fwww.1000bulbs.com%2F38626%2F%3Futm_source%3DSmartFeedShoppingcom%26utm_medium%3DShopping%26utm_term%3DCFTR26WGX24q827NAED2087926Watt4PinGX24q3Base2700KCompactFluorescentCFLLightBulb%26utm_content%3DCFTR26WGX24q827NAED2087926Watt4PinGX24q3Base2700KCompactFluorescentCFLLightBulb%26utm_campaign%3DSmartFeedShoppingcom%26site%3Dwww.shopping.com&linkin_id=8044909&searchID=p8.53002526dfe03de95e06&DealName=CFTR26W%2FGX24q%2F827+-+NAED+20879+-+26+Watt+-+4+Pin+GX24q-3+Base+-+2700K+-+Com...&dlprc=2.27&crn=USD&istrsmrc=0&isathrsl=0&AR=1&NG=5&NDP=&PN=1&ST=7&DB=sdcprod&MT=phx-pmt3-1&FPT=DSP&NDS=&NMS=&MRS=&PD=&brnId=14305&IsFtr=1&IsSmart=0&DMT=1000&op=&CM=&DlLng=&RR=&cid=&semid1=&semid2=&IsLps=&CC=&SL=&FS=&code=&acode=&category=&HasLink=&frameId=&ND=&MN=&PT=&prjID=&GR=&lnkId=&VK=

7/30/2019 How Does a Fluorescent Starter Work

3/4

accept energy in one form (for example, energy from a high-speed electron as in a TV tube -- seeHow

Television Works) and emit the energy in the form of visible light. In a fluorescent lamp, the phosphor

accepts the energy of ultraviolet photons and emits visible photons.

The light we see from a fluorescent tube is the light given off by the phosphor that coats the inside of the

tube (the phosphorfluoresces when energized, hence the name). The light of a neon tube is the colored

light that the neon atoms give off directly.

How Fluorescent Lamps WorkThe central element in a fluorescent lamp is a sealed glass tube. The tube contains a small bit of

mercury and an inert gas, typically argon, kept under very low pressure. The tube also contains a

phosphor powder, coated along the inside of the glass. The tube has two electrodes, one at each end,

which are wired to an electrical circuit. The electrical circuit, which we'll examine later, is hooked up to an

alternating current (AC) supply

When you turn the lamp on, the current flows through the electrical circuit to the electrodes. There is a

considerable voltage across the electrodes, so electrons will migrate through the gas from one end of the

tube to the other. This energy changes some of the mercury in the tube from a liquid to a gas. As

electrons and charged atoms move through the tube, some of them will collide with the gaseous mercury

atoms. These collisions excite the atoms, bumping electrons up to higher energy levels. When the

electrons return to their original energy level, they release light photons.

As we saw in the last section, the wavelength of a photon is determined by the particular electron

arrangement in the atom. The electrons in mercury atoms are arranged in such a way that they mostly

release light photons in the ultraviolet wavelength range. Our eyes don't register ultraviolet photons, so

this sort of light needs to be converted into visible light to illuminate the lamp.

This is where the tube's phosphor powder coating comes in. Phosphors are substances that give off light

when they are exposed to light. When a photon hits a phosphor atom, one of the phosphor's electrons

jumps to a higher energy level and the atom heats up. When the electron falls back to its normal level, it

releases energy in the form of another photon. This photon has less energy than the original photon,

because some energy was lost as heat. In a fluorescent lamp, the emitted light is in the visible spectrum -

- the phosphor gives offwhite light we can see. Manufacturers can vary the color of the light by usingdifferent combinations of phosphors.

http://home.howstuffworks.com/tv.htmhttp://home.howstuffworks.com/tv.htmhttp://home.howstuffworks.com/tv.htmhttp://home.howstuffworks.com/tv.htmhttp://home.howstuffworks.com/tv.htmhttp://home.howstuffworks.com/tv.htm

7/30/2019 How Does a Fluorescent Starter Work

4/4

Conventional incandescent light bulbs also emit a good bit of ultraviolet light, but they do not convert any

of it to visible light. Consequently, a lot of the energy used to power an incandescent lamp is wasted. A

fluorescent lamp puts this invisible light to work, and so is more efficient. Incandescent lamps also lose

more energy through heat emission than do fluorescent lamps. Overall, a typical fluorescent lamp is four

to six times more efficient than an incandescent lamp. People generally use incandescent lights in the

home, however, since they emit a "warmer" light -- a light with more red and less blue.

As we've seen, the entire fluorescent lamp system depends on an electrical current flowing through the

gas in the glass tube. In the next section, we'll see what a fluorescent lamp needs to do to establish this

current.