Vintage Christmas Tree lights

[broadgage]

Originally Posted by PaulR

I think they are mainly from Woolworths. They sold very good Christmas back in the day.

Indeed, and Woolworths also uniquely sold strings of 12 series connected E10 lamp holders, but WITHOUT any lamps. This being for customers who wished to make their own selection from the many novelty shaped 20 volt, 3 watt lamps.
They also of course sold complete and ready to use lighting sets.

[PaulR]

Originally Posted by broadgage

Indeed, and Woolworths also uniquely sold strings of 12 series connected E10 lamp holders, but WITHOUT any lamps. This being for customers who wished to make their own selection from the many novelty shaped 20 volt, 3 watt lamps.
They also of course sold complete and ready to use lighting sets.

That explains why there were so many different designs of bulbs on sale there. Pick-n-Mix!!

[McMurdo]

Hi Andrew that Osram pre-lit tree looks rare to me, never seen one in the flesh. I bet most of them were thrown long ago. Puts things into perspective with the artificial trees we get today. Simple pleasures.

[The Philpott]

Two sets of new NOMA push-in sets arrived here a few weeks ago. (Not my choice)

They are fundamentally the same design as older sets of this type, but one set (which only had provision for 39 lamps out of the factory) has blown 2 lamps quite quickly, and a 3rd one was changed today as it was flickering. It may not have helped that the mains has been up by 2 to 3% lately, combined with the overvolt of 2.5% already present due to the missing socket but it's still pretty poor. The colouring of the shades and lamps is patchy, the 13A plug is light as feather but doesn't seem actively dangerous (i replaced it anyway as it was sealed and i decided to include a diode in the new one)

All the older sets we are using this xmas have not blown a single lamp. I think i'll stick with them as long as possible.

Dave

[Beeseebulbchap]

Hi Kevin.

Thanks for your kind comment regarding the Osram pre-lit tree. it is a certainly a nice item, plus the fact that it has retained its box too. I think I paid only £1 for it at the car boot sale.

I think the only likely area of failure, will be the wire 'branches' fatiguing where they are strapped to the main trunk. In addition, the lampholders are held on the end, just using tiny rubber bands.

Suffice it to say, the tree is carefully opened out, after being slid out of its box.

Somewhere in my collection, I do have an old Osram / GEC catalogue which features the Lilliput tree. Unfortunately, it is currently AWOL, however I did come across a few nice examples of Christmas lights in my 1956 edition of Brown & Co's. catalogue.

Simple pleasures, like you say.

Kind regards. Andrew.

[Pylon man .]

1960’s & 1970’s sets. The contents were the same while the packaging was updated to also incorporate the British safety standard kite Mark.

[AndiiT]

Originally Posted by Beeseebulbchap

.....a few nice examples of Christmas lights in my 1956 edition of Brown & Co's. catalogue........
Andrew.

I once owned a set of Pifco "Moonlites" (shown in the catalogue) purchased at a Chapel Christmas jumble sale many years ago; it was one of only two sets of lights I had seen with 8 bulbs, the other being a set of Bubble lights which one of my friends parents' owned.

Andrew

[Radio Wrangler]

Yes, usually you got a dozen 20v bulbs.

I'm certain my parents' visits to various relatives in the run up to Christmas were not quite independent of plans to get me to fix everyone's Christmas tree lights. 24v lorry tail light bulbs would do at a pinch if I couldn't find anything else to get them going. It's just that a series circuit seemed to defeat everyone just trying bulb swapping. I had a huge old AVO CT38 as my only test meter. It must have looked impressive!

David

[emeritus]

Our 20V bulbs set (extended from 12 to 16 bulbs some years ago) was initially intermittent this year and stopped working altogether as I was putting it up. Turned out to be a lampholder failure, the rivet forming the centre contact having pulled through the paxolin insulation disc. Fortunately I still have some spare lampholders from when I cannibalised two sets to make the one longer set.

[Buzby123]

If you want to roll your own vintage lights, here is a way to design and 3D print some.

I've no interest in building vintage lights, but the OpenSCAD script method caught my eye, as it looks like a way to design custom control knobs, and I do need some of these.

Merry Christmas,

Buzby

https://www.youtube.com/watch?v=1h9f...re=emb_rel_end

[broadgage]

A few years ago I hade a load of modern but vintage style Christmas lights, for 24 volt nominal supply.
Low cost of lamps was a concern as significant use was expected.

Cheap wire ended E10 lamp holders from ebay were connected in series groups of 4, and with 10 groups/40 lamps along a length of twin twisted flex.
Cheap 6 volt/6.3 volt pilot lamps used, purchased IIRC for only £8 per hundred.

12 such strings (480 lamps) used on a large Christmas tree. Others used outdoors.
Locating failed lamps is easy since any failure extinguishes only 4 lamps, replace all 4 if significantly blackened.
6 volt pilot lamps are cheaper and more reliable than 24 volt lamps, hence groups of these.

The supply is from an off grid home energy system with a very large 24 volt battery bank charged by renewables.
60 amp circuit to Christmas tree, 12 way fuse board to give 12 circuits each fused at 5 amps for the lights.

[Herald1360]

I picked up a free tub of 6V 2.4W clear olive MES Christmas lamps yesterday. 32 of the 33 worked


As one does, today I thought I'd try out a theory of mine that bulbs in a half wave recified series string actually consume slightly over half their normal power thanks to the positive tempco of the filaments.



On a statistically insignificant sample of one bulb, measured using dc, this does indeed seem to be the case:


Bulb at 6V took 0.34A = 2.04W
Bulb at 4.24V (6V/√2) took 0.28A = 1.19W

[Philips210]

Hi

About 25 years ago we had a set of Christmas tree lights from CPC. I think they were described as an ornate set. The wiring eventually became very fragile so the set was scrapped but I saved the bulbs. These have a standard MES base, the filament bulb itself is a standard cylindrical shape but placed inside a conical glass envelope, see attached pic.

I will eventually make a new set using these bulbs but underrun them to prolong their life.

Regards,
Symon

[The Philpott]

Post No.632

Chris, i only did a couple of manual checks on this subject with a DC clamp meter (the accuracy of which at these low currents might be questioned despite the facility to null out geomagnetic fields.) The results came out between 63%-75% of the normal dissipation on full AC. I may do a proper check before i put them all away in January.

Dave

[Herald1360]

My check was done using smooth dc from a bench PSU and two separate DMMs- one for voltage at the bulb itself, t'other to measure the current from the PSU. There might be some difference to be found if the measurements were done with true half sine wave voltage vs full sine if filament thermal inertia gets in on the act too......
I haven't got suitable meters to make any accurate RMS volts or amps measurements under the genuine conditions though.

[broadgage]

An incandescent lamp, or a series group of such lamps, connected to AC mains via silicon diode will absorb more power than it would if run at half voltage.

This may be proved very simply as follows.
Obtain three identical mains voltage lamps.
Connect two in series, directly to the mains. Connect the third single lamp to the mains via a silicon diode.

The single lamp connected via the diode will be appreciably brighter than either of the series pair of lamps.

Alternatively attempt calculation.
Consider a 240 volt 100 watt heating element. If such an element be connected to a 120 volt supply, then it will absorb not half power, but one quarter power, 25 watts.
If instead the element is connected to 240 volt mains via a diode , then it will absorb half power, 50 watts. It is in effect worked at full power for half the time, and at zero power for the rest of the time.
The non linear resistance of lamps complicates the matter somewhat, and the fact that light output varies rapidly with small changes in voltage, adds more complication.

If one desires to work an incandescent lamp at normal brightness from a half wave rectified supply, then the lamp needs to be designed for about two thirds of the supply voltage. NOT HALF.
So a set of Christmas lights worked from 240 volt AC mains via a diode, is subjected to an effective voltage of about 160 volts.
This also may be confirmed by experiment.
Obtain two identical mains voltage lamps.
Connect one lamp to the mains via a diode.
Connect the other lamp to the mains via a Variac.
Adjust the variac such that both lamps are of equal brightness.
Measure the Variac output. It will be about 160 volts.

[Herald1360]

Originally Posted by broadgage

An incandescent lamp, or a series group of such lamps, connected to AC mains via silicon diode will absorb more power than it would if run at half voltage.

This may be proved very simply as follows.
Obtain three identical mains voltage lamps.
Connect two in series, directly to the mains. Connect the third single lamp to the mains via a silicon diode.

The single lamp connected via the diode will be appreciably brighter than either of the series pair of lamps.


.......

That's not the issue I was playing about with.....

Half wave rectified mains across a pure resistance will dissipate half the average power that normal mains does (same power dissipated but with 50% duty cycle). This means the RMS voltage of the half wave supply is 1/√2 of the normal supply voltage. Half the normal RMS voltage would of course simply dissipate a quarter of the power across the same resistance.

I was pondering the non-constant resistance of a bulb filament with temperature which for a highly positive tempco as with tungsten would mean that the filament resistance at lower power (and hence temperature) would be lower. My simple experiment with dc voltages (where the RMS voltage is by definition the same as the DC voltage) did (within its limitations) confirm this.

[mrpickwick]

Hello,

Has anyone bought Noma filament fairy lights of recent? Since they were bought out by Leisuregrow i have noticed the wiring to be a really dark green as opposed to the lighter green.

Still have a set of 35 Premier berry lights, Premier brass lanterns and Pifco glass shaded lights. I emailed Premier early December and they said they wouldn't be making filament sets anymore so makes me wonder if Noma will be the only company that does.

Hope everyone had a good Christmas

[The Philpott]

Yes, my other half bought a couple of sets of Noma filament lamps for the festivities.
I did notice the one set had more than one colour of insulation used (a subtle difference, but noticeable. Different shades of green.) I assumed the reel on the production line ran out and a slightly different one was started just as this set was being made.

When i changed the plug on one of them i did notice that there was double insulation present on the cable as per modern regs. Other than that i'm not too impressed with them. (See earlier posts by me) Missing parts, budget plugs and poor quality control.

Dave

[Stuart R]

I bought my Noma/LeisureGrow set referred to in post 590 a few weeks ago. Half Price - what a bargain!

Not such a bargain as it turns out. They wouldn't light up: One empty bulb holder and 7 other open-circuit bulbs, with clearly broken filaments and some with very blackened glass around the anti-fuse. Clearly 'previously - enjoyed'

Is it just by chance that all the duff bulbs were orange or red? All blues and greens appear to have continuity, although this could just be the anti-fuse.

Can't comment on the shade of the green cable, sorry. It's a fairly good match for the green of the bulb holders and is the same colour throughout.

I did notice a small plastic tool included with the spare bulbs to help with bulb removal - when did that become necessary? I thought finger nails were good enough. Maybe a regulation 'tool' is required for gaining access to potentially live terminals.

Regards,

SR