Classifications

• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
  • H05B41/14—Circuit arrangements
  • H05B41/36—Controlling
  • H05B41/38—Controlling the intensity of light
  • H05B41/40—Controlling the intensity of light discontinuously
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B47/00—Circuit arrangements for operating light sources in general, i.e. where the type of light source is not relevant
  • H05B47/10—Controlling the light source
  • H05B47/16—Controlling the light source by timing means
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
  • Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
  • Y02B20/40—Control techniques providing energy savings, e.g. smart controller or presence detection

Definitions

• the present invention relates to a hybrid device for the step regulation of the brightness of a lamp for street lighting and/or general exterior lighting.
• hybrid denotes a device which uses a magnetic regulator in combination with electronic control circuitry.
• the regulation of the brightness of a lamp for street lighting and general exterior lighting in other words the regulation of its light emission, is an important requirement in certain circumstances, when the aim is to make energy savings, or when it is simply desirable to reduce light pollution.
• a magnetic step regulator for high-intensity discharge lamps is described in US patent 5,216,333. It comprises a discharge lamp and a magnetic regulator.
• the magnetic regulator has three windings, namely a first winding connectable to an alternating current source, a second winding and a starting circuit connected to the discharge lamp for lighting the lamp, and a third winding having a ballast capacitor connected between said winding and a power tap.
• the magnetic regulator of the cited patent also has an inductive reactor and a switch with a switchable conductive path, connected in series with each other between one end of the third winding and the tap. When the path is conducting, the reactor stores energy from the capacitor and reduces the power available to the lamp, thus reducing the light emission.
• the switch is controlled by an actuator which can be operated by a manual command or by means of movement sensors, which detect the presence of persons who would benefit from the lighting.
• the aforementioned patent is intended to be associated with a lamp for lighting an outdoor space which is only occasionally occupied. It is known that it is undesirable to extinguish the discharge lamp completely when the space is unoccupied, since its relighting requires a certain amount of time and causes certain difficulties in operation. Repeated relighting also shortens the service life of the lamp.
• the aforesaid patent is therefore intended to achieve a step reduction of the voltage, primarily by reducing the power absorption, and consequently a saving of energy. This voltage reduction leads to a reduction of brightness.
• the voltage reduction is carried out manually or automatically, by means of movement sensors.
• the known regulation device essentially uses only electrical components, in a rather large quantity.
• the object of the present invention is also to achieve a saving of energy, but is based on the finding that, especially on very busy roads, the traffic intensity is not constant during the hours of darkness, but decreases as the night goes on. It would therefore be useful if the light emission of a lamp for street lighting and general exterior lighting could be varied over the different time bands characterized by decreasing traffic. However, the light emission can only be reduced by an amount that does not affect transport safety.
• the reduction of light emission may also be necessary in ordinary city streets where, particularly after midnight and before dawn, the number of moving persons is generally very small.
• the principal object of the invention is therefore to reduce in a stepped way the brightness of a high-intensity discharge lamp for exterior lighting in general in specified periods of time.
• Another object of the invention is to reduce in a stepped way the brightness of lamps, used for exterior lighting in general, which are different from discharge lamps, but in which the brightness depends on the supply voltage, including incandescent lamps.
• Yet another object of the invention is to reduce the brightness of a lamp with a device which can be installed in the light fitting and made from small, highly economical and reliable components.
• a further object is to reduce the brightness of a lamp in order to slow its aging and thereby lengthen its service life.
• a hybrid device for the step regulation of the brightness of a lamp for street lighting and general exterior lighting, comprising an autotransformer having a plurality of taps with corresponding voltage outputs, at least one of which is a low-voltage output, and an electronic control circuit, supplied through said low-voltage output and including a rectifier and voltage stabilizer, a timer for presetting periods of time during the hours of darkness and a multiplicity of control circuits acting as an interface between the timer and electromechanical relays arranged in parallel between the corresponding voltage outputs of the autotransformer and a supply line of a load consisting of a street lighting lamp, in order to supply the voltage required to give the lamp the desired brightness in each period that has been preset by means of the timer.
• the invention has the advantage of permitting a reduction in light pollution, which, as is known, particularly affects astronomical observation and has a negative effect on aerial navigation.
• Figure 1 shows a block diagram showing the principal components of the hybrid device according to the invention
• Figure 2 shows a circuit diagram of a particular embodiment of the hybrid device according to the invention
• Figure 3 shows a table of the components indicated in the circuit diagram of Figure 2.
• Figure 4 shows schematically a light fitting to which the device according to the invention is applied.
• FIG. 1 shows the functional components of the device according to the invention.
• the hybrid device comprises an autotransformer (block 1), having a plurality of taps with corresponding voltage outputs, and an electronic control circuit, supplied through a low-voltage output of the autotransformer and including a rectifier and voltage stabilizer (block 2), a timer (block 3) and a multiplicity of control circuits (block 4).
• the multiplicity of control circuits acts as an interface between the electronic circuit and the autotransformer, by means of electromechanical relays arranged individually (as shown in Figure 2) between the corresponding voltage outputs of the autotransformer and a supply line of a load consisting of a street lighting lamp (block 5) of the discharge type.
• Figure 2 shows a specific embodiment of the hybrid device according to the invention.
• the intensity of vehicular traffic in the hours of darkness, from sunset to dawn in the summer has been approximately determined, and has been divided into five bands, characterized by way of example as follows:
• the device is intended for lamps with power ratings from 70 W to 150 W.
• TR1 is an autotransformer provided with a multiplicity of taps, for example eight taps with corresponding voltage outputs, as indicated, the first and last of these being 0 N and 220 N at the input (phase Lin and neutral ⁇ j n ).
• a 12 V output is used to drive the electronic circuit, while the 206 V, 198 V, 190 V, 182 V and 174 V outputs are used to reduce the voltage across the load consisting of the discharge lamp, indicated only by L ou t and Nout.
• the power of the transformer is calculated by assuming a cosD value of 0.75. In other words, for a 150 W load, a 200 VA (150 x (1/0.75)) transformer is used.
• the electronic circuit is supplied by the autotransformer TR1 through a rectifier BR1 and a voltage stabilizer (indicated as block 2 in Figure 1) which uses a dropping resistor R20 and a Zener diode ZD1 and filter/reservoir capacitors CIO and CH. Clearly, a different stabilizer configuration could also be used.
• IC1, IC2 and IC3 form part of the timer indicated as block 3 in Figure 1.
• IC1 is a 14-bit binary counter with an oscillator, such as the 4060 model, produced, for example, by Semiconductor Components Industries, Denver, Colorado, USA, or by other manufacturers.
• the output will deliver a pulse every 4.55 minutes.
• IC2 is a first decade counter, such as the 4017 model produced, for example, by National Semiconductors, Arlington, Texas, USA, or by other manufacturers.
• IC2 When the signal from IC1 passes through IC2, a pulse is generated every 45.5 minutes.
• the second decade counter of the same type as the first, is used to activate the outputs when necessary.
• the time intervals are selected according to the time bands indicated above: 90 minutes, 90 minutes, 45 minutes, 90 minutes, and finally to the lowest output. This is done by linking outputs Q 0 to Q 9 to each other as shown: Q 0 and Q 1 joined together, Q 2 and Q 3 joined together, Q 4 left alone, Q 5 and Q 6 joined together, and the last three, Q 7, Q 8 and Q 9, all joined together.
• the counters must be reset whenever power is supplied; otherwise any output might be activated.
• C2/R3 supply a reset pulse to IC1, C3/R5 reset IC2 and C4/R7 reset IC3. Since the outputs of the counters may fluctuate, R4 and R6 are used as pulldown resistors.
• the 4017 decade counter has a clock enabler (pin 13), which enables the clock if it is low and disabled, and keeps the state of the output irrelevant to the clock pulses if it is high.
• This additional possibility of the IC3 is used by taking a positive reference voltage from the tenth output and supplying this to pin 13 via D6 to ignore the clock and keep the output in this state until the supply voltage of the device is turned off at dawn by means of a switch of the twilight, timed or other type.
• R14 is a pulldown resistor which sends a low input to pin 13 when pin 11 of IC3 is not active.
• IC4 included in block 4 of the control circuits shown in Figure 1, is an NPN transistor array, where each transistor drives its own corresponding relay so that the five outputs connected to the load are activated individually.
• Resistors R8 to R12 are base resistors for the transistors. Diodes Dl to D5 protect the transistors.
• Capacitors C5 to C9 keep the relays energized for a few milliseconds, to prevent losses of voltage which would harm the lamps. Since the relay which is being de- energized keeps its contacts closed for a few milliseconds, the autotransformer TR1 has to withstand a brief short circuit between the outputs during switching. 1 ohm resistors Rs, in series with the relay contacts, are used to limit the current.
• the device according to the present invention can reduce the light emission of the lamp on whose fitting or lamp housing it is mounted.
• this shows a light fitting to which the device according to the invention is applied.
• the fitting is indicated as a whole by the number 6, while inside it the number 7 indicates a lamp of the aforesaid type, 8 indicates a magnetic reactor, 9 indicates a starter, 10 indicates a power factor correction capacitor, 11 indicates the device according to the invention, and 12 indicates the line input terminals.
• the installed components are shown schematically and are suitably connected by a line conductor and a neutral, represented by the bolder line and the thinner line respectively.
• the device can be located in a different position from that shown, for example on the base of the pole supporting the lighting equipment.
• energy saving it has been calculated that the annual saving is of the order of 30-35% on average when the device according to the invention is used.

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• Circuit Arrangement For Electric Light Sources In General (AREA)

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Applications Claiming Priority (2)

Publications (1)

Family

ID=11456162

Family Applications (1)

Country Status (3)

Cited By (3)

Citations (6)

• 2002
  • 2002-03-08 IT IT2002RM000131A patent/ITRM20020131A1/it unknown
• 2003
  • 2003-02-28 WO PCT/IT2003/000118 patent/WO2003077616A1/en not_active Application Discontinuation
  • 2003-02-28 AU AU2003217456A patent/AU2003217456A1/en not_active Abandoned

Patent Citations (6)

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