Street lights are now ubiquitous, light at night in some countries large highways. But where do they come from? And who snaps when on and off?
When were lanterns invented?
Formerly, as now served streetlights to the improving security in public places. In order not to stumble in cities on stock sinister ways, you lit in ancient times the streets with specially established lanterns. Fast forward well into modern times, one can observe how the fuels changed within a relatively short time: Have to mid-19th century still mainly walnuts and rapeseed oil used to power the streetlights, rose the larger cities then on gas lighting by http://www.bridgat.com/shop/led-night-lights/. The gas was of central gasworks led to the lanterns and burned there. The first permanent electric street lighting in Germany was taken in June 1882 in Nuremberg in operation and a short time later, in September, Berlin also moved to. But that gas lighting was far from sold: Until after the 2nd World War many places lit their streets with gas which provide well proven available and technologically was and also for a very unique light ambience ensures.
How are street lights turned on?
The mystery streetlight does not end with the switch to electric lamps. Even more exciting is the question of the connection of the streetlights: When they go to nd when again? For the control, there are several possibilities:
Control via Twilight switch
The circuit on a dimmer switch is done either centrally or locally. In a central controller turns on light sensitive resistor , the control lines and Fort switching devices, for example, an entire city dusk dependent and at the same time on or off. In contrast, the decentralized control via dimmer switch. By switching individual streets additional control lines can be avoided.
Other control techniques
But the lights can also by an audio frequency or radio ripple control or a timer can be controlled. The timer works by a stored astronomical calendar in which the twilight times are stored.
When going to the lanterns and when the lights go out again?
This question is not easy to answer with a time. Instead, it must be said: When it gets dark, go to the lamps when it gets light, they turn off. Depending the time of the season, but also the weather. On very cloudy and dark days, controlled via a twilight sensor lights go possibly earlier and later again.
Why go from street lamps, when you step on the other hand?
No, at an earthquake-proofing, it is not that street lights go out after a good kick for a minute or two. Instead, the reason – as so often – the technique used: In streetlights today mainly are mercury vapor lamps and sodium vapor lamps used. This does not shine as a classic light bulb due to the heating of a filament, but by an arc between two electrodes. This is so sensitive that it breaks off at a vibration, for example, in a blow to the lantern, and again after cooling the lamp can rebuild.
What are streetlights? And how far they are apart?
For more facts about streetlights complacent? The height of streetlights unfortunately we can not clearly indicate. Because they are limited only by lanterns model from. Between 3 and 6 meters high can be as a lantern. On the question of the distance between the lights there are also no universal answer: The determined namely the respective municipality, which prepares the streetlights. Depending lantern distance but also on the type of road to be illuminated: In residential areas the streetlights are less far apart than in commercial areas.
Where to Report broken streetlights?
Even streetlights get broken once. Since the municipal administration may not always be anytime anywhere, there are central offices where one can report broken streetlights. However, they differ from city to city. In smaller communities it is aimed most directly to the Administrator, in larger are often Stadtwerke responsible.