Fluorescent lamp choke - use in tube amp?

[Giaime]

Hello to all!!!

I found a flourescent lamp choke (you know, heavy white things mounted near the lamp starter). It has 45ohm dc resistance which I just measured. And it has these writings on it:

Type:N/39 Lamp W:30-32-2x14-15 [delta]t:55° tw:120

V:220 Hz:50 And then some semi-cancelled letters:

IL (or maybe TL): 0.xx 0.xx (those x are unreadable numbers)

cosx:0.45 (the x maybe a greek phi)

(note: the [delta] is in greek letter)

What does they mean? How a flourescent lamp works? What does the starter do?

And most important... if this is a choke, can I use it in my tube amp just to filter the B+ for the screens of the power tubes (2 EL84 per channel) and for the anode of the drivers (a couple of ECCxx series)?

Thanks in advance!!!

[kmtang]

I believe the choke used in florescent tube is for AC operation. The one we are using for B+ filtering is for DC.

With DC current through a choke designed for AC operation, the magnetic core mostly get saturated and its Inductance will become less significantly.

Just my 2 cents.

Johnny

[silicon-surfer]

A fluorescent lamp works by passing an arc from one end of the lamp to the other. In each end of the lamp there is a small filament like the filament in an incandescent lamp, which is ignited briefly to heat the gas inside the lamp - this is done by the starter which switches the filaments on for a moment and then off (usually several times which is why fluorescents flicker when they come on). The gas inside the tube is a mercury vapour which produces ultra violet light when the arc passes through it, and then the phosphour coating on the inside of the glass of the tube converts the UV to visible light.

The Choke in a fluorescent lamp limits the current that flows through the lamp after the lamp has ignited.

Don't know how this helps with a tube amp though!

[Giaime]

Originally posted by silicon-surfer
A fluorescent lamp works by passing an arc from one end of the lamp to the other. In each end of the lamp there is a small filament like the filament in an incandescent lamp, which is ignited briefly to heat the gas inside the lamp - this is done by the starter which switches the filaments on for a moment and then off (usually several times which is why fluorescents flicker when they come on). The gas inside the tube is a mercury vapour which produces ultra violet light when the arc passes through it, and then the phosphour coating on the inside of the glass of the tube converts the UV to visible light.

The Choke in a fluorescent lamp limits the current that flows through the lamp after the lamp has ignited.

Don't know how this helps with a tube amp though!

Thanks!!! I've searched the net and now I understand how a fluorescent lamp works. Now I'd like to know if someone is using the reactor choke in a tube amp...

[Zen Mod]

discussed long time ago on r.a.t
it works

[Giaime]

Originally posted by choky
discussed long time ago on r.a.t
it works

r.a.t.????? Sorry I don't know this.

[amperex]

The small & common 13-watt twin tube reactors have little inductance. The small inexpensive $8 to $10 Hammond chokes are superior for filtering in power supplies.

[gainmona]

In the last number of italian magazine "Costruire HiFi" (Building Hi-Fi) is a project of tube pre-amp using a fluorescent lamp choke in the PSU who seems work wery well.


Ciao.

[Giaime]

Originally posted by gainmona
In the last number of italian magazine "Costruire HiFi" (Building Hi-Fi) is a project of tube pre-amp using a fluorescent lamp choke in the PSU who seems work wery well.


Ciao.

Thanks!!! Anyone has details on this misusing of that choke??? I understand that Hammonds are better, but here in Italy 20 euro + 10s/h.... a bit high.

[Ouroboros]

Originally posted by Giaime


r.a.t.????? Sorry I don't know this.

Probably the usenet news group: rec.audio.tubes