hot choke

[SparkyTris]

Untitled

• SparkyTris
• 1 Apr 2015
• 1

what is the insulated coil of wire in this luminaire?
I feel it must be some design of ballast.... it appears to be running very hot, although it looks as if it was designed to be running hot.
however, not so hot that it melted the starter cartridge, which it has.

I would be eternally grateful to a full explanation of this design!

thanks
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[ban-all-sheds]

 

[winston1]

It is a resistive dropper. Very inefficient. You are probably using more watts in the dropper than the light.

 

[333rocky333]

The starter looks more like damage caused from inside itself, due to continually trying to strike the lamp, they then get extremely hot, often melting the housing.

 

[SparkyTris]

B-A-S, the ring of wire to which I have drawn attention is, I believe, double insulated: that is, the conductor is insulated in the normal manner of wire by a basic PVC(?) plastic jacket. this has then been fed through a supplementary woven textile heatproof(?) tube. Basic+supplementary insulation = double insualtion....?

the damage to the starter cartridge - yes possible was caused by a bad starter indeed, but please be aware that I had turned the cartridge around in the photo. when I dismantled the lumi the cart was turned around with the melted part right in line with the hot wire. the light starts and runs reliably. the wire ring gets too hot to touch.

sticker on back of lumi rates tube at 40W, luminaire at 150W.

as can be seen from close inspection, one of the lines from the BNC fitting rivets straight to the metal backplate of the lumi, making the (enamelled) metal possibly line volts. (depending on how the BNC is secured)

Winston - resistive dropper - does this then simply fulfil the same current limiting function as the choke in a standard tube lumi? ie, limits the current once the arc has struck?

what is the purpose of this design? (other than as a sort of X-rated light fitting for those who like their luminaires to be hazardous)

 

[JohnW2]

what is the purpose of this design? (other than as a sort of X-rated light fitting for those who like their luminaires to be hazardous)

Cheaper than a choke? (as well as much less efficient and more potentially hazardous)

Kind Regards, John

 

[winston1]

sticker on back of lumi rates tube at 40W, luminaire at 150W.

as can be seen from close inspection, one of the lines from the BNC fitting rivets straight to the metal backplate of the lumi, making the (enamelled) metal possibly line volts. (depending on how the BNC is secured)

Winston - resistive dropper - does this then simply fulfil the same current limiting function as the choke in a standard tube lumi? ie, limits the current once the arc has struck?

what is the purpose of this design? (other than as a sort of X-rated light fitting for those who like their luminaires to be hazardous)

Gosh it is even worse than I thought, 110watts lost in the dropper.

A BNC fitting is a type of coaxial plug used in video and RF. Are you referring to the earth connection from the choc block?

Resistive dropper fulfils the same limiting function as a choke. As JohnW2 says it is done for cheapness but once you factor in running costs over the life of the fitting it probably won't be cheaper.

But hey you could run it on DC mains which which you can't with a choke. (I once saw fluorescents on DC mains in Calcutta in the 70s and they were standard units with a large dropper resistor in series).

 

[bernardgreen]

In the 1950's ( and probably later ) there were fittings where an incandescent lamp was used as the ballast.

 

[ban-all-sheds]

A BNC fitting is a type of coaxial plug used in video and RF. Are you referring to the earth connection from the choc block?

Don't forget that the first 6 characters of the OP's username are extremely misleading - he is not an electrician.

 

[Taylortwocities]

Don't forget that the first 6 characters of the OP's username are extremely misleading - he is not an electrician.

Many (apparently) "expert" posters, who give advice, on this forum are not qualified electricians either

 

[ban-all-sheds]

Indeed not, but do they adopt a misleading, in that context, username?

 

[Taylortwocities]

True, and I see that your campaign againgst The Sheds is starting to take effect

 

[JohnW2]

Many (apparently) "expert" posters, who give advice, on this forum are not qualified electricians either

Very true, but I don't recall any of them claiming to be electricians, let alone "experts".

I think the reality is that if all the people to whom you refer were to disappear, the forum would be a much quieter place - whether that would be good or bad is, I suppose, a matter of opinion!

Kind Regards, John

 

[bernardgreen]

Lets face it, anyone with Sparky in his name is either a dodgy chap who works with live wires or has a talking piano.

 

[JohnW2]

Lets face it, anyone with Sparky in his name is either a dodgy chap who works with live wires or has a talking piano.

Well, there are at least a few around here who have "spark" (even if not "Sparky") in their username - and I think that most, if not all, of them are probably genuine electricians.

Kind Regards, John