Is Induction lamp based streetlighting in UK/Europe/USA/World still being sold?

[PointyOintment]

Sodium lamps are certainly more pleasant to the eye, but LEDs are a bit of a no brainer when it comes to energy costs (150W vs 600W+ adds up for thousands of lamps) another positive is they tend to throw light downwards so there is a reduction in light pollution (at least that is how the council advertised the upgrade to LED). You will need thick curtains however if you have a bedroom window near a lamppost. We had LEDs installed 4/5 years ago, wasn't a fan of the bright white light at first, but used to it now.

I had the opposite experience. My street used to have LPS and was upgraded to LED about a year and a half ago. The lamp that's visible from my bedroom is about one lot along and on the other side of the street. Also, the top of my bedroom window is at nearly the same elevation as the lamp head, due to the house being higher than the street.

The old lamp, with its hemispherical diffuser, used to shine in my bedroom window quite brightly at night, casting a bright projection of the window on the wall, which would then by scattering illuminate the whole room dimly. When I was a little kid, my parents had to install a blackout blind so I could sleep. (When we renovated, it was replaced by a fancy wooden top-down/bottom-up blind, which doesn't block as much light, but I'm no longer as sensitive to light when sleeping.)

The new LED lamp emits much less light sideways, and while you can still see a projection on the wall, it's very dim and it doesn't perceptibly illuminate the room. When it was installed, I was surprised to be in pretty much total darkness the first time I turned off the room lighting at night with the blind open—the old LPS lamp gave enough light to see my way around the room by!

Somewhat off the direct topic, but maybe of general interest.

I grew up in the UK, and back then, (dodging dinosaurs), street lighting was controlled by electro-mechanical time switched. A small synchronous motor drove gearing turning the switch once per 24 hours. settings on the clock face would flip a microswitch on/off at the set times.

The timers for street lights had one extra feature, more gearing for a cam that turned once per year. This cam advanced/retarded the set times to follow daylight at (about) 52 degrees latitude. So long as someone went around and adjusted them after any power outage (rare in those days) they worked fine. Turning on the lights at dusk, and off at daybreak.

Ah the venerable Venner, I begged a few of those from the guys who refitted the lights in my street with photoelectric cells, the Venner switches were an absolute work of mechanical art and must have been in use for decades

Yes, I think that was the make. I had one, just could never think of a good use for it :-)
But you are right, mechanical works of art.

Big Clive did a video on a Sangamo brand streetlamp timer, for anybody who wants to see what one of those timers looks like inside:

[Cyberdragon]

Many cities are going to smart city streetlighting where the "controllers" can remotely control the lights with schedules but also turn entire cityblocks on in case of an emergency. The lamps can be remotely controlled and signal themselves when something is out of order eg a light is not performing to specifications or other problems. Annual energycosts can be monitored in case of running over budget low cost schedules or lighting patterns can be selected, eg one of two lights on etc. Etc.
Endless possibilities.

https://www.currentbyge.com/ideas/intelligent-cities
http://www.lighting.philips.com/main/systems/lighting-systems/citytouch

Pfft, "smart". As predicated by that word being totally opposite...hack fodder! The only reason it's not widespread is because these controllers are somewhat rare and people are far more interested in the traffic signals than the road illumination.

How do series string lights avoid going out like old fairy lights?

[Kjelt]

Pfft, "smart". As predicated by that word being totally opposite...hack fodder! The only reason it's not widespread is because these controllers are somewhat rare and people are far more interested in the traffic signals than the road illumination.

Don;t understand what this has to do with the subject. Ofcourse as with any internet connected facility it is a potential target for hackers.
The "smart" part is that in case of an emergency for instance or a criminal at large entire city blocks can be put to full illumination as a simple example.
Or to save energy put at dimming levels in case there is little trafic for instance on christmass nights or other occasions people stay at home.

How do series string lights avoid going out like old fairy lights? 

What do you mean with strings? They can be individually controlled have their own IP or wireless connection and mains connection.

[Cyberdragon]

You seemed to confuse the bottom with the top. I mean the older style incandescants/discharge.

[dmills]

Series string bulbs are designed so that tension in the filament holds a contact gap open, when the filament snaps, the contact closes shorting out the failed lamp and leaving the series chain functional (The constant current driver just has a lower terminal voltage).

You can see something similar in the old school series Christmas light sets, except they were usually directly across the mains so as more lamps failed the rest of the chain got brighter until the one bulb (usually IIRC with a white cap) that did not have the shorting switch failed and shut the whole thing down.

Regards, Dan.

[PointyOintment]

How do series string lights avoid going out like old fairy lights? 

What do you mean with strings? They can be individually controlled have their own IP or wireless connection and mains connection.

Referring to those described in james_s's post. My understanding (and it's a bit shaky because I'd never heard of them in street lighting before this thread) is that they're not wired directly in series, but instead there's one wire, carrying 6.6 amps, with several current transformers wrapped around it, one for each bulb. When one of the bulbs fails, that current transformer just stops drawing power, and the power supply can reduce its voltage a little bit to maintain the 6.6 A current.

From the early 1920s up into the 1960s many systems were installed using HV 6.6A series loops which used an electromechanical constant current regulator to power a loop with anywhere from a handful up to hundreds of lights all wired in series. These used special incandescent lamps at first, but later HID, mostly with special ballasts that really are just current transformers for each lamp.

I assume "special incandescent lamps" means

Series string bulbs are designed so that tension in the filament holds a contact gap open, when the filament snaps, the contact closes shorting out the failed lamp and leaving the series chain functional (The constant current driver just has a lower terminal voltage).

[bodger]

Pfft, "smart". As predicated by that word being totally opposite...

They're pretty smart the new systems, I was speaking some installers a few years back; They were installing outposts that control the lamps replacing the old light sensor fitted on top of every ballast (I think that's the technical term). Anyway these outpost can individually be programmed, they can report back things like when a lamp is blown, power factor, power usage, brown outs, etc. I think what the council liked is they have power meters in each individual outpost, which means they no longer have to use the energy supplier's reading and pay for power lost in the wire getting to the lamp.

[Cyberdragon]

How do series string lights avoid going out like old fairy lights? 

What do you mean with strings? They can be individually controlled have their own IP or wireless connection and mains connection.

Referring to those described in james_s's post. My understanding (and it's a bit shaky because I'd never heard of them in street lighting before this thread) is that they're not wired directly in series, but instead there's one wire, carrying 6.6 amps, with several current transformers wrapped around it, one for each bulb. When one of the bulbs fails, that current transformer just stops drawing power, and the power supply can reduce its voltage a little bit to maintain the 6.6 A current.

From the early 1920s up into the 1960s many systems were installed using HV 6.6A series loops which used an electromechanical constant current regulator to power a loop with anywhere from a handful up to hundreds of lights all wired in series. These used special incandescent lamps at first, but later HID, mostly with special ballasts that really are just current transformers for each lamp.

I assume "special incandescent lamps" means

Series string bulbs are designed so that tension in the filament holds a contact gap open, when the filament snaps, the contact closes shorting out the failed lamp and leaving the series chain functional (The constant current driver just has a lower terminal voltage).

I assume the contact is on the filament holder somewhere near the bottom? (This is actually from a current store listing )

[Kjelt]

Referring to those described in james_s's post. My understanding (and it's a bit shaky because I'd never heard of them in street lighting before this thread) is that they're not wired directly in series, but instead there's one wire, carrying 6.6 amps, with several current transformers wrapped around it, one for each bulb. When one of the bulbs fails, that current transformer just stops drawing power, and the power supply can reduce its voltage a little bit to maintain the 6.6 A current.

We don't have those in our country but I believe I once saw this in Italy being used.

[PointyOintment]

Referring to those described in james_s's post. My understanding (and it's a bit shaky because I'd never heard of them in street lighting before this thread) is that they're not wired directly in series, but instead there's one wire, carrying 6.6 amps, with several current transformers wrapped around it, one for each bulb. When one of the bulbs fails, that current transformer just stops drawing power, and the power supply can reduce its voltage a little bit to maintain the 6.6 A current.

We don't have those in our country but I believe I once saw this in Italy being used.

That would make sense, given that

For a long time I was not aware of any series streetlighting anywhere else in the world however we did discover similar systems being used in Italy.

[james_s]

Series string bulbs are designed so that tension in the filament holds a contact gap open, when the filament snaps, the contact closes shorting out the failed lamp and leaving the series chain functional (The constant current driver just has a lower terminal voltage).

You can see something similar in the old school series Christmas light sets, except they were usually directly across the mains so as more lamps failed the rest of the chain got brighter until the one bulb (usually IIRC with a white cap) that did not have the shorting switch failed and shut the whole thing down.

Regards, Dan.

No, that's not how the Christmas lights work, there is no spring tension. The shunt is coating with an insulating oxide and acts as an open circuit. When the filament opens, the full mains voltage appears across the shunt and flashes through the oxide completing the circuit.

Incandescent series streetlights indeed wire the lamps directly in series but the bulbs themselves don't have shunts. Instead there is a shorting disc between the prongs where the special lampholder plugs into a socket. The way it is set up, you can pull the lampholder out of the socket and the contacts in the socket spring closed to complete the circuit, and when you plug it in, if the lamp itself goes open the shorting disc will flash through its mica insulator and also complete the circuit. The lamps are special in that they are rated for 6.6 Amps rather than being rated for a specific voltage. The actual voltages they run at are oddball values that depend on the wattage, typically anywhere from 12V to around 90V. The lamps are printed only with a rating in lumens though, 6000L is one of the more common sizes.

When HID lamps are used on these same series circuits, each lamp has an isolation current transformer. They did make special mercury vapor lamps intended for direct operation on special series circuits but they had some serious drawbacks. Due to the fact that a mercury lamp won't restrike until it cools off, a momentary power interruption would activate the shunts in the whole string of lamps, requiring them to all need replacing.

[Cyberdragon]

There's a website that seems to have alot of vintage electrical info.

http://www.kbrhorse.net/streetlights/understanding_shunts02.html

[james_s]

That site has some great info, if you back up one level there is a picture of a series lamp, they are easily identifiable due to the unusually short V shaped filament. The picture posted earlier in this thread is actually a 120V lamp with a C filament.