Automation of Street Lighting

Use a photo-switch (at least, that's what we call them). They can be set to switch on or off depending on the amount of light. There should be lots of suppliers for this.

Light intensity switches are standard practice for street light installations in the UK.

v

As roomates point out its a simple work to build up the set, I can also offer you one circuit. but where shall we send you? (I;d be hard put to post any picture here because the conmmunicatin optic fiber which broken by earthquake hasnt been fixed yet)

try talking to "X10 Pro" they have some advanced techniques for automating such things

otherwise, you can do like everyone else - use photo switch (adjustable intensity) for on-off with the amount of light outside - google "photo sensor high power street lights"

In Brazil, the photo switch is also a standard, and is present over each lamp support. I installed some myself at home for my backyard illumination. They support a considerable ammount of power for a relly low price (my ones costed less than USD 10,00 each, and are expected to last over 5 years). You don't even need internet to find some. Go to the next hardware shop and they'll certainly show you 2 or 3 models they have off-the-shelf, so you can examine them.

Either you could install a light intensity switch on each light or put a junction box in and wire one light intensity switch for several of the lights. Another option is to install some PLC controls, this would also give the town the room for future automation of their traffic lights.

If it is not too late your supplier should be able to supply you with a lighting fixture already fitted with a photo cell for just such a task, if it is a small village I would suggest using the individual photo cells instead of a single one or the timer circuit. I have never had any problems with this method, but occasionally a batch will have the photo cells wired incorrectly and the light will blink on and off, they just need to be re-connected correctly by you.

Photo cells can also be retro fitted easily, there are many types available to fit your space requirements. See the links below they are for US companies, but I guessing your in the UK if so see the last link (some of those featured looked like they were made from bakelite, ex 1930's stock)

http://www.geindustrial.com/cwc/products?pnlid=3&id=photocon

http://www.residential-landscape-lighting-design.com/store/PPF/Category_ID/58/products.asp

http://www.streetlightonline.co.uk/Photocells/index.htm

Just a thought...have the lights on a motion detector. Save the world, reduce power, turn off the lights when you leave.

Of course!

Two local authorities near this location have recently advocated turning the street lights off between 00:00 and 05:00 on the basis that there are so few people out-and-about at those times and a lot of energy is being used to light them.

A motion detector on each lamp makes a lot more sense and would save even more. They may now expect to receive correspondence on this subject. Thank you for the suggestion.

I think that a timer circuit will have to be used in series with the photo switch, then.

Motion detectors would only work with lamps with immediate response. And more: The circuit would have to be done in a way that a car's motion is detected along the way, and a series of lamps ahead of the car would need to be turned on. It's no use to turn lamps above a car running...

And the detectors would have to be duplicated to include people walking detection and car movements. And would have to incorporate some control or special position to avoid actuation by trees branches, birds, and teenagers looking for fun (I can imagine guys using the lamps to light words when turned on in a certain sequence...).

Definitely, motion detection is not good. Turn everything off by a timer in the middle of the night. Let the photo switches do their job at sunrise and sunset.

Photo cell is the right solution as advocated by all.Even in day time if light is low for some reason this can switch on w/o human intervention.Plenty of stuff is availableon the net

hi,

As above all person said use photo switch for lighting, I just add you use 1 photo switch with Mag. contactor for many light. Its so cheap than others. we use a lot.

habib haider

karachi.

If you have electricity available a photo cell is the answer.

An alternative is to have all the people in the village raise their hands above their heads at sunset. MANY HANDS MAKE LIGHT(S) WORK!

LOL, funniest thing I've seen in a long time!

I find it difficult to believe that the OP is a trained electrical engineer who has never heard of a photo cell for street lights. That has been the design standard for 30+ years that I know of. Nobody does remote control of street lighting any longer. Also, forget motion sensing; HID lighting takes up to 15 minutes to "strike" and get to a high enough intensity to do any good.

Well, I've known some old electrical engineers who were not able to keep up with technology. Of course, as you say, photo-switches have been around for decades so it is very unusual.

Then again, I've known a few new graduates to whom the obvious answers just don't come immediately. Takes them a couple of years to acquire that.

You're also right about using motion detectors for street lighting. If they're using ordinary incandescent lamps, it's going to work though I wouldn't recommend it. If a car passed through, you'd get a nice flash everytime the car passed a lamp post ! Distracting to say the least.

There are plenty of places where a car already gets a flash as it passes through. This technology already exists:

Red traffic lights...

Speed cameras...

Ah yes. I saw one on the way home. 'Even waved back at a cop. Nice guy.

Nice joke! First time I've heard it. Thanks.

The standard solution, used worldwide, is to simply buy fixtures with an incorporated photo cell, or alternately control whole lighting circuits with a photo cell controlled switch.

Which one depends on the particulars of the lighting circuit and what it is used for (general street lighting, along highways, etc), along with whether it is a completely new lighting system including the wiring, as in along a new highway, or whether they are "replacement" fixtures on a pre-existing circuit, which may or may not be separate from the supply system as a whole, from a potential control standpoint.

Obviously, from a cost standpoint it is easier to have each street light have its own photo cell and just tie it in to the adjacent power lines, with no separate circuit at all.

As a historical note, older incandescent street lights in many places in the US were wired in series to save wiring, and allow operation off a higher voltage supply that was switched on and off from some central location. In each fixture, was a spring loaded "clamp" that was held open by a resistive wafer shaped material (I don't recall what the material was). This clamp was part of the circuit, and was wired parallel to the bulb in each separate fixture. When the bulb burned out, the much increased current flow through the wafer caused it to melt or burn away, allowing the clamp to close and complete the circuit so that the remaining series wired lights would remain lit. Sounds strange in a way, but it was standard technology of the day. I used to have one of the bulb holders, with the "clamp" on the back of it. It was removable so when the bulb was replaced, a new wafer was installed also.

Greg

Hi guy,

Instead of using the time switch, why don't you use the light sensitive automatic switch which is triggered by the light intensity and the sensitivity can be tuned.

This kind of switch can be easily found in the market.

Brgds,

Seno

I have designed RTC based programmable switch which can Turn On and Turn OFF street light or water pump at set time of day.

If we use Light intencity based device due to dust and heavy rains there may be problem in sensing.

Bharat,

We've used light intensity based devices for years and, personally, I've never had to clean them. The only time when I needed to climb up was when I needed to replace them. Some of those have been up and running for so many years that I can't remember when they were installed.

I don't want to rain on your idea or work, but I've always held the belief that simplest is best in most cases.