I wondered how long it would be...

The point is that it is a choke. The capacitor(s) within a fluorescent fitting are called capacitor(s), the terminal block within it is called a terminal block, the screws within it are called screws etc. etc. - so why is the choke within it called a "ballast"?

Ballast to my mind's eye is the stuff they put under a railway sleeper, a road, or the bottom of a boat. How does that transmute to an component in a florescent fitting? The only point of commonality is that both are heavy for their size.
 
As to choke, this would be in Henry's ....
The component within a fluorescent fitting is a choke and, as you say, has an inductance that can be measured in Henrys
but not quite that easy, it throttles back how much can flow, chokes it ...
Quite so - that is presumably how chokes came to get their name, probably ages before either of us was born.
, but also provides a volt boost ...
... as would any inductor (aka "choke") used in the same way
so not sure I could select a choke but ballast shows fluorescent tube to be with it, rather than electrical properties.
Try as I may, I can't understand what you were trying to write there.

... but why "ballast"?

Kind Regards, John
 
Ballast to my mind's eye is the stuff they put under a railway sleeper, a road, or the bottom of a boat. How does that transmute to an component in a florescent fitting? The only point of commonality is that both are heavy for their size.
As I understand it (per what EFLI wrote) the thinking was that the choke in a fluorescent fitting in some senses results in electrical 'stability' (which some may see as remotely analogous to the stability provided by ballast to a railway sleeper or ship - but that seems to me to an extremely contrived/obscure argument to produce a new word for an electrical component that already has a perfectly satisfactory name!

Kind Regards, John
 
As I understand it (per what EFLI wrote) the thinking was that the choke in a fluorescent fitting in some senses results in electrical 'stability' (which some may see as remotely analogous to the stability provided by ballast to a railway sleeper or ship - but that seems to me to an extremely contrived/obscure argument to produce a new word for an electrical component that already has a perfectly satisfactory name!
I thought you were the great defender of language democracy (evolution) so would accept that if some/enough/all call these things ballasts, for whatever reason, then that is what they are.

As 'ballast' is in the dictionary for this electrical usage then surely you must think it correct.


It seems you are as adamant as I when a word's usage is something with which you disagree.
 
I thought you were the great defender of language democracy (evolution) ....
I don't think that 'defender' is really the right word. My position is that I accept the inevitability of evolution of language - which has necessarily been occurring continuously ever since human beings uttered their first words.
so would accept that if some/enough/all call these things ballasts, for whatever reason, then that is what they are.
If enough/all (not just 'some') had, for whatever reason, come to use the word "ballast" to refer what had previously (for many decades) been called "chokes" then, yes, that would represent an evolution of language which I would accept (whether or not I was 'happy' with it).

However, since chokes always have been, and continue to be, called chokes in almost every other situation, I really don't see why they have come to be called something different when they exist in fluorescent light fittings or similar.

It would be the same if spanners were called spanners, or screwdrivers were called screwdrivers, in almost every situation, except when they were being used to work on a washing machine, when they had totally different names!
It seems you are as adamant as I when a word's usage is something with which you disagree.
Just as I have no choice but to accept that language evolves, even in relation to evolutions which I don't particularly like, I also have to accept that "ballast" is the word that has come to used to refer specifically to chokes in fluorescent fittings etc. since otherwise I would not be able to communicate effectively with those who use that word - I actually suspect that a good few electricians, and sellers of electrical items (particularly younger ones) would probably not know what I was talking about if I referred to "the choke" in a light fitting.

Kind Regards, John
 
The “ chokes” in florescent fittings run fairy warm. I would guess a choke in a 5 foot fitting dissipates around 10 watts. As well as I squared R losses there will be iron losses of course.
 
The “ chokes” in florescent fittings run fairy warm. I would guess a choke in a 5 foot fitting dissipates around 10 watts. As well as I squared R losses there will be iron losses of course.
There will obviously be some loss of energy (as heat) both in the resistance of the winding and in the core. I thought that these losses would be pretty small, hence leaving little scope for them to be reduced (by reducing voltage), but maybe I under-estimated them.

I'm p[probably not going to be around much, if at all, during the next few days, so it might be the weekend, or early next week, since you see me again!
 
AFAIW the word 'choke' originated as a form of smoothing DC. A properly designed series inductor will be low resistance but a high impedance.
 
Looking up "ballast" in the dictionary, it refers to something heavy used to stabilise a ship etc. It could be argued that the ballast in a flouro fitting is used to stabilise the current through the tube (I suspect the tube is essentially current driven with voltage determined by the physics in the tube) and so it's a similar meaning.
Also, going back "a few years", I recall we used to have ballasted and non-ballasted ignition coils. In a number of cars I changed to a ballasted setup to improve starting. There the ballast resistor is simply a resistor - there to stabilise the coil current that would otherwise be excessive running a (approx) 6V coil on 12V.
 
I recall we used to have ballasted and non-ballasted ignition coils. In a number of cars I changed to a ballasted setup to improve starting. There the ballast resistor is simply a resistor - there to stabilise the coil current that would otherwise be excessive running a (approx) 6V coil on 12V.

Yep, if it would fire when being cranked, but died as soon as you stop cranking - the resistor has gone open circuit. Rather than a ballast resistor, I would call that a dropper resistor. Sometimes the resistor was a resistive element inside the length of the loom, rather than an actual resistor at the coil.
 
I suppose the ballast balanced the cranking and non cranking volts to the coil, and in the fluorescent it balanced the start and run current in the same way, well pointed out.
 

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