For somebody to come up with the math and the engineering of such device is just astounding! Got a lot more respect for the fluorescent now in the era of leds 😁 great video btw thanks for sharing
Actually, without a ballast, the current wouldn't raise sowly like that. It is actually quite fast, in that if the lamp happened to fire at say 120vac, then it would be the same as a dead short and the current limiter would be a fuse or circuit breaker. So you end up with a big spark and maybe a screwed up lamp. But usually 120v is not enough to fire the lamp, so most of the time no current flows and nothing happens.
Remember, in the US 120 V mains voltage is actually about 170 V peak. The figure quoted for mains voltage is actually the "RMS" value. The peak value is then: 1.414 x 120V == 169V
nice movie but explaination is simply said not correct ( incomplete and WRONG) 1. when the neon-bimetal bulb glows, the filliament is NOT heated (only the bi-metal is) 2. the heating of the filliaments only starts as bi-metal closes (which stops the glowing of the neon and ends the heating of the bi-metal) 3 then, when the bi-metal opens (after ~2 sec) the filliaments are hot and the sudden opening will cause induction and so HV over the lamp, making it easyer to start ionising the gass, that will then produce UV-light 4 the uv-licht will be transformed to normal vissible light by the powder on the inside of the tube, this powder is available in all shades and collours
+Marc Zand Your comment made me see the whole picture. Thank you. In the first stage, isn't the tungsten wire heated at all? not even a tiny little bit?
+Daniel Blanco Lauzurica the current that flows through the neon light is ~1mA, the current to heat the filliament is ~750mA. You now can draw your conclusion about the amount of heat in the first stage ;-) greetz Marc
Ballast prevents high current like a resistor. Except the ballast resistance increases with current. The lamp has very little resistance if there is no resistor like thing then it will form short-circuit. Hope u understand that the starter turns it self off after tube starts conducting...there fore current goes through one terminal (filament) to another. The filament it self does not glow when tube has started glowing.
This video is not for beginners, you can research more background prior to viewing, so for some all they need is a quick video to link concepts they already are familiar with. If you want a detailed video with proper explanations than you can donate the funds required to create such a video.
he explained everything how it should be but yeah... little fast... by the way, in reality, e- moves faster than the way it is depicted... so would you ask electricity to run by giving plenty of pauses... :D why don't you slow down the speed from featured settings option...?
Awsome Video! I'm glad to see someone has taken the time to learn about these simple lamp fixtures. In my opinion, these type of lamps last the longest compare to any other lights. I have 6 or 7 of them all 20-30 years old and still using the same bulbs that they started with =D A+ man keep up the good work!
A roughly 40 yo T12 4ft long bulb just gave up the ghost here a week or two back, one of the filaments opened up (I checked it with a DMM.) That's very good life!
they usually have a boost converter to kick a high enough voltage into the lamp without needing a starting system. you'll find these in laptops or small flouro torches
probably the same thing or they have a 12/24volt to mains (110 or 230 volt) inverter. you could probably run a regular flouro fitting off DC you'd just get the blackness you get on flouro tubes at one end and with the tube slightly over-driven and a saturated ballast cause the ballast works best on AC, but it should start pretty quick though.
I think you have missed the role of low work function coating on the filaments. Without this coating a very high voltage is reqd to intiate the arc which is called COLD START and not recommended.It reduces life of the tube.The coating when heated by the filament emits electrons which assists the creation and establishes the arc but has no role to play once the arc is struck. It is noticed that when the coating is depleted the filaments only heat up but the arc is not struck.Cheap quality lamps have improperor inadequate coating.The Cold start method can avoid the use of starter by introducing an electronic pulse.
+Cheshire Cat Janis is right, US AC power reverses polarity 120 times per second. It's easier to see this if you look at a portion of the sine wave that's not starting at zero. If you look at a single "cycle" starting at its peak of ~170V (the 120V rating is only the RMS rating, it's 170V peak to peak) you'll see it go +170 → 0 → (-)170 → 0 → +170 in 1/60 of a second - note it crossed zero twice, and thus reversed polarity twice. The frequency is expressed as "60 cycles per second (or 60Hz)" because a single cycle is a full sine wave that peaks both positive and negative. Edit: stupid RU-vid thinks I'm trying to make strikethrough text instead of indicating voltage polarity -_-
@@american0153 , I think you haven't been to school 😂One ac oscillation consists of onepositive half cycle and one negative half cycle. ... The direction changesafter every half cycle. Therefore, thedirection of an alternating currenthaving frequency 50 Hz changes 100 times in one sec. First thing, never mock others if they are wrong, second keep your knowledge correct.
Bulb gets hot . Bi metal strip bends.Makes contact . lower resistance path. Current flows through strip instead of bulb so Bi metal cools and re-sets. If the arc has established no current flows through the bulb. Pretty good eh.
They usually have some kind of AC inverter built into the fixture that converts 12 volts DC into 120 volts AC. Like the thing you plug into the cigarette lighter socket to power laptops and what not.
Nice one, although the starter action is missing - it shorts circuit and the begginning but than it disconnects as I recall - could be included into animation.
The starter is basically a neon bulb with a bimetallic strip. When the bulb heats up, the contacts touch and short out the bulb. Maximum mains power then reaches the tube for a split second. Bulb cools down, contacts open and power disconnects - causing inductive kick through the tube. Once the tube is fully lit, very little current flows through the starter, because the two filaments at each end of the tube have warmed up so draw less current. So now the starter will just glow without getting hot enough to heat and short the contacts.
@@djb22 re: "Once the tube is fully lit, very little current flows through the starter" I think it is BECAUSE the little neon bulb no longer fires. You know a neon bulb fires at a higher voltage than it takes to sustain the glow?
@@djb22 re: "But why does the neon bulb no longer fire?" Gas physics. The fluorescent tube, once fired, draws the voltage down further and the Neon bulb extinguishes, purportedly. It is possible to overdrive a little neon bulb, but it would not last long that way.
the starter switch is in the open position with only a small current running through the circuit through neon gas when the starter tube heats enough the switch closes, current increases dramatically resulting in much larger magnetic fields which collapse raising voltage the fluorescent tube now arcs i assume the resistance through the vaporized mercury is much lower than the resistance through the starter resulting in the starter cooling and opening the video is way to fast and not incomprehensible and most likely plain wrong.
1:14 Tubul fluorescent functioneaza la aproximativ 40 volt ,dar pentru aprindere este necesar un impuls de peste 800 volt. Alimentat direct din retea nu se va aprinde.
One thing I can't understand is HOW the starter stay OFF after the lamp starts. The starter is ON when cold and OFF and hot. So, moments after the lamp starts, the starter should be cold again, right? As there's no energy passing through it to keep it warm. Please someone explain me!
The excited gas in the lit tube has very little resistance so there's almost no voltage across it, not near enough to light the starter. It'd be like if you tried wiring a flashlight bulb in parallel to a shorted AA battery--bulb wouldn't light. The choke also reduces the voltage significantly after the gas is ignited so it won't blow up the tube, as shown in the video. So.. not enough voltage to keep the starter lit.
The other way around. The bimetallic switch in the starter is open (cold) initially and must be open after the fluorescent lamp has turned on (otherwise the lamp would be shorted). I think the text at 0:31 (Small neon lamp heats up a bimetallic switch) is misleading. This happened already when the AC was applied at 0:14, when the neon lamp was lit and the switch heated and closed. The text at 0:36 (1. Bimetallic switch heats up and pops into "off") is wrong. Because the switch shorts out the neon lamp, it goes out and the bimetallic switch *cools* and opens. Finally, when the fluorescent lamp is lit, there is not enough voltage to relight the neon lamp.
The reason they limit the current is because they know the tube can operate at a very low voltage/current. They have to keep it matched to 120v or it will blow. The question everyone avoids Q. how much v/amps do you need to ignite the gas ?
1:35 that's what happened whan i plugged in a fluorescent tube to a microwave oven transformer with stepped down voltage to about 400 volts (secondary)
It would have been better if all this was shown with a little slow motion. You have to read and see that freaking electrons moving so fast. Why can not this all be shown slow for understanding.
so according to you the capacitor across bimetalic strip is not needed for operation. . u didnt not explain y there is a capacitor across that bimetalic strip
That's not a capacitor; the capacitor-looking symbol below the switch is actually the neon lamp. The schematic symbols look similar, except a neon lamp is supposed to be enclosed in a circle. The parallel plates in its symbol represent the lamp's electrodes, and are used instead of the curly-cue (➰) to differentiate it from an incandescent lamp.
One Cycle = 2 Changes in direction. It's just word play. doesn't really change the theory of operation. Many of us never passed grade school, Not because we were stupid, more like we weren't really interested in much of their propaganda. Many ditched conventional education systems. Go with God and may he bless you in all you attempt.
i change the bulb and the starter , does the ballast is defective? is there any reading if i use a VOM meter to check the continuity of the ballast? if so what is the reading?
