|
General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
|
Thread Tools |
15th Mar 2018, 2:00 am | #1 |
Banned
Join Date: Nov 2014
Location: Derry, Northern Ireland, UK.
Posts: 167
|
Unknown, valve/sodium lamp pinout?
Hi forum, would any of you know the pinout for this lamp, which ones are for the heater and which are for the filament? The pins on the valve are offset and not evenly/uniformly spaced if you know what I mean.
I can only find this about it, page 24, Laboratory lamps. http://www.lamptech.co.uk/Documents/...01960%20UK.pdf I see that it says 100V.A.C supply, is that for the filament voltage or the heater voltage or both? The writing on the box says; GEC Ltd. Patent Osram P.D Sodium SL/D1.3 For A.C. Use Made In England Any help would be very much appreciated, Thank you. Last edited by tritone; 15th Mar 2018 at 2:12 am. |
15th Mar 2018, 8:19 am | #2 |
Octode
Join Date: Jan 2004
Location: Southport, Merseyside, UK.
Posts: 1,156
|
Re: Unknown, valve/sodium lamp pinout?
I don't know anything about this particular lamp but as it looks like a discharge lamp you may need to run it with a ballast resistor otherwise as soon as it strikes it will pass a very high current and go pop.
John |
15th Mar 2018, 8:52 am | #4 |
Nonode
Join Date: Aug 2015
Location: Cambridge, Cambs. UK.
Posts: 2,196
|
Re: Unknown, valve/sodium lamp pinout?
ISTR using a lamp like this back in the day in a lab for spectroscopic calibration on the sodium D-lines. It came with its own control ballast unit - a transformer I think.
Martin
__________________
BVWS Member |
15th Mar 2018, 11:59 am | #5 |
Dekatron
Join Date: Apr 2012
Location: Worksop, Nottinghamshire, UK.
Posts: 5,549
|
Re: Unknown, valve/sodium lamp pinout?
If it is an ordinary sodium lamp there will only be two connections.
Just use a Megger like a continuity tester. They need a constant current with a striking voltage equal to what you get when you connect a DVM in parallel to the Megger. The current needs to be enough to warm up the sodium until you get the yellow glow you want. |
15th Mar 2018, 12:40 pm | #6 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,951
|
Re: Unknown, valve/sodium lamp pinout?
That description says "The lamps have 4-pin caps such that the cathodes may be electrically heated before starting, to enable the lamps to start easily on the 230V mains electricity supply" so I'd expect there to be a heater in there!
And it talks about 1.3 Amps: which at 240V would give a murderously-bright light from something so small, so I suspect the 1.3Amps is the heater. |
15th Mar 2018, 12:44 pm | #7 |
Dekatron
Join Date: Apr 2012
Location: Worksop, Nottinghamshire, UK.
Posts: 5,549
|
Re: Unknown, valve/sodium lamp pinout?
If it is pure sodium it will need a heater and a warm-up time before light will be seen.
|
15th Mar 2018, 2:41 pm | #8 |
Guest
Posts: n/a
|
Re: Unknown, valve/sodium lamp pinout?
A sodium lamp needs a current limited supply (via a choke) and will have an arc voltage of the order of 70 to 150V depending on length of arc. So, say 100V at 1.3A, not an enormous amount for a bulb. They will run (but warm up very slowly) on a lesser current. I would try a 40W florescent lamp fitting.
|
15th Mar 2018, 2:58 pm | #9 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
|
Re: Unknown, valve/sodium lamp pinout?
Open this link and keep scrolling, the pin connections etc are given, including calc. for R:
flickriver-lb-1710691658.us-east-1.elb.amazonaws.com/photos/51699638@N06/sets/72157634373949553/ EDIT: link won't highlight, copy and paste in URL address box. EDIT again!: Another link: https://www.lighting-gallery.net/gal...=35&pid=114109 Lawrence. Last edited by ms660; 15th Mar 2018 at 3:14 pm. |
15th Mar 2018, 3:14 pm | #10 |
Nonode
Join Date: Aug 2015
Location: Cambridge, Cambs. UK.
Posts: 2,196
|
Re: Unknown, valve/sodium lamp pinout?
Sodium lamps intended for street lamps normally include neon gas for the first strike to heat up and vaporise the sodium -hence the initial red glow before the golden sodium light appears.
A laboratory application, which I suspect this lamp is for, would not normally want the 'polluting' neon spectrum and typically uses a hot cathode for vaporisation - hence the extra couple of pins. I found the attached circuit for typical control gear. I guess that if you explore with a DMM, a couple of the pins will exhibit the resistance of the cathode heater, though the rating remains a puzzle. Martin
__________________
BVWS Member |
15th Mar 2018, 3:15 pm | #11 |
Guest
Posts: n/a
|
Re: Unknown, valve/sodium lamp pinout?
A whole hobby of spectrum lamps, makes us lot look sane (ish!) The values stated lead to 70W, I was in the right ball park.
|
15th Mar 2018, 3:28 pm | #12 |
Guest
Posts: n/a
|
Re: Unknown, valve/sodium lamp pinout?
As far as I know the starting gas is a Penning mixture of Argon and Neon, this has the lowest striking voltage, rather clever. And once the sodium has started the voltage isn't enough to light the Argon/Neon, you need the gas to get the Sodium hot anyway.
I may seem very knowledgeable, but a few weeks ago I found a book "Electric Lamps" from 1955 in a second hand book shop, this one (the shop) http://cottagebookshop.co.uk/ if you are in the area well worth a look. The shop has featured in a couple of "Midsommer Murders" too. |
15th Mar 2018, 9:59 pm | #13 |
Nonode
Join Date: Dec 2012
Location: Kirk Michael, Isle of Man
Posts: 2,346
|
Re: Unknown, valve/sodium lamp pinout?
Yes, a laboratory sodium lamp for sure. We used them at tech back in the day (1961 ish) I recall one experiment was to use fraunhoffer diffraction to calculate the diameter of lycapodium * (sp) pollen, which I seem to recall was around 26 (nm or angstroms?) - you do forget some things, but I could go out to the 'bike shed and find my notes for certain. Obviously mad!
* (Lycapodium was very uniform in size, so ideal to give us something to aim for.) Les. |