EP2628652B1 - LED light source for a dwarf signal - Google Patents

Description

The present invention relates to an LED light source arrangement for a dwarf signal according to the patent claim 1 and the patent claim 2.

• HALT 40,
• FAHRT MIT VORSICHT 41 oder kurz VORSICHT 41,
• FAHRT 42.

Dwarf signals (for: signaux nains suisse) are used by the Swiss Federal Railways (SBB) and more than 30 private railways and serve as a beacon to secure the routes within a railway station. Dwarf signals thus fulfill both shunting and traction functions. As a rule, dwarf signals are always placed to the left of the track. Dwarf signals are located directly on the ground next to the track, only in special cases they are raised for better visibility. A dwarf signal has three white lamps or three lights arranged in an L, see FIG. 1 , Three different signal terms are displayed:

• STOP 40,
• RIDE WITH CAUTION 41 or briefly CAUTION 41,
• TRAVEL 42.

On the back of a dwarf signal 50, the words CAUTION 41 or TRAVEL 42 are displayed with a white light; For this purpose, the light source is used for the upper light; The light is directed through a mirror on the back. This back signaling as a luminous oblique bar means that a road on TRAVEL 42 or on CAUTION 41 is released and thus an oncoming vehicle is to be expected. The return signaling also allows a train driver to read the dwarf signal 50 from behind, this is particularly important in shunting.

For the replacement of light bulbs by LED's is in writing US 2004/0070519 A1 [1] discloses a signal lamp in which bulbs are replaced by LED bulbs. In this case, Fresnel lenses are used for optical adjustment. The LED bulbs already include one own energy supply. This solution does not include an electrical replica of the bulb.

To date, it has not been possible to replace the incandescent lamps in a dwarf signal by LED technology in a migration step. Today, only solutions are on the market that build on a new product (completely new dwarf signal with housing and other physical interface, i.e. current values adapted). In order to make the compatibility of an LED bulb with the incandescent lamp, the electrical and mechanical parameters must match. For the realization, the parameters of the incandescent lamp (40V / 20W) are decisive. The incandescent bulbs used in the dwarf signals have proven themselves over many years and locomotive drivers have adjusted to the resulting perception characteristics. Due to the installed base, i. In order to control the Domino interlockings of Integra AG and the electronic interlockings, the 40V / 20W interface to the dwarf signals must be maintained. In this case, nothing has to be changed at the interlocking system. This maintenance must also solve the problem of heat radiation, since LEDs have a very low power consumption.

From the patent application AT 505 154 A4 2008-11-15 [2] an optical signaling device is known which contains at least one LED light source, supply electronics and an electrical load component. This load component is therefore required in order to "display" the same current-voltage characteristic curve in relation to the existing safety technology in the interlocking. For better heat dissipation, the load component is thermally coupled to the housing of the signaling device.

The present invention is therefore an object of the invention to provide an LED light source arrangement for a dwarf signal, which replaces the incandescent lamp arrangement in existing dwarf signals, so that the electrical control and visual perception remain unchanged and the LEDs are exposed to any additional thermal stress.

This object is achieved by the measures specified in the independent patent claims. Advantageous embodiments of the invention are specified in further claims.

1. i) Lichtstromerzeugung,
2. ii) optische Ausbreitung,
3. iii) Phantomlicht,
4. iv) Kennliniennachbildung und
5. v) Wärmeabfuhr

wie folgt:

1. i)Lichtstromerzeugung
   LED-Quelle statt Glühlampe
2. ii) optische Ausbreitung
   Dazu wird eine in einem Plexiglasrohrbefindliche Kollimatorlinse eingesetzt und die homogene Lichtwirkung nach aussen wird durch eine mattierte Scheibe sichergestellt. Letztere dient als "Ersatz" einer matten bzw. "milchigen" Glühlampe.
3. iii) Phantomlicht
   Die verwendeten Komponenten LED-Quelle, Kollimatorlinse, Plexiglasrohr und mattierte Scheibe verhindern das Auftreten von Phantomlicht.
4. iv) Kennliniennachbildung
   Die Steuerlogik ist zur Nachbildung des Energieverbrauchs (Kennlinie) einer Glühlampe mit einem Energiebalancer verbunden, der die nicht benötigte Energie einem Lastwiderstand zuführt.
5. v) Wärmeabfuhr
   Die im Lastwiderstand "vernichtete" Energie muss thermisch abgeführt werden, da die Lebensdauer von LED-Quellen durch unnötige thermische Belastung massiv reduziert wird, muss der Lastwiderstand ausserhalb des Zwergsignals platziert werden.

The invention solves the vorgenanten sub-problems, namely

1. i) luminous flux generation,
2. ii) optical propagation,
3. iii) phantom light,
4. iv) characteristic simulation and
5. v) heat dissipation

as follows:

1. i) light generation
   LED source instead of light bulb
2. ii) optical propagation
   For this purpose, a Kollimatorlinse located in a plexiglass tube is used and the homogeneous light effect to the outside is ensured by a frosted disc. The latter serves as a "replacement" of a dull or "milky" light bulb.
3. iii) phantom light
   The used components LED source, collimator lens, plexiglass tube and frosted disc prevent the appearance of phantom light.
4. iv) Characteristic simulation
   The control logic is connected to emulate the energy consumption (characteristic curve) of a light bulb with a Energiebalancer that supplies the unneeded energy to a load resistor.
5. v) heat dissipation
   The energy "destroyed" in the load resistor must be dissipated thermally, since the life of LED sources is massively reduced by unnecessary thermal load, the load resistance must be placed outside the dwarf signal.

1. a) Durch eine mechanische Konstruktion von LED-Quelle, Plexiglasrohr und Kollimatorlinse kann dies steckerkompatibel kompakt realisiert werden und bei deren steckerkompatiblen Ausgestaltung braucht die Glühlampe nur durch diese Konstruktion ausgetauscht zu werden. Zusätzlich muss die mattierte Scheibe noch angebracht werden.
2. b) Die Unterbringung der elektrischen Komponenten auf einer Leiterplatte erlaubt eine einfache Installation im Zwergsignal.
3. c) Für Platzierung und Anschluss des ausserhalb des Zwergsignals (genau Zwergsignalgehäuse) benötigten Lastwiderstands sind Anpassungen hinsichtlich Verkabelung und Fixierung erforderlich. Dies stellt jedoch einen weit geringeren Aufwand dar, als eine neue Ansteuerung in einem Stellwerk vorzusehen.

This may result in the following additional benefits:

1. a) By a mechanical construction of LED source, Plexiglas tube and collimator lens this can be realized plug-compatible compact and in their plug-compatible design, the bulb needs to be replaced only by this construction. In addition, the frosted glass must still be attached.
2. b) The placement of the electrical components on a circuit board allows easy installation in the dwarf signal.
3. c) For placement and connection of the outside of the dwarf signal (exactly dwarf signal housing) required load resistance adjustments in terms of wiring and fixation are required. However, this represents a much lower cost than to provide a new control in a signal box.

The aforementioned three advantages make it possible to retrofit the dwarf signals successively in a railway station. This would not be possible with a so-called central solution, that is, with a new control on the interlocking side. Successive retrofitting means that in the event of failure of an existing incandescent lamp dwarf signal, the abovementioned components can be virtually kept as spare parts.

• Figur 1 Zwergsignal mit den drei Signalbegriffen;
• Figur 2 erste Ausführungsform der Erfindung mit einer einzigen LED-Quelle, die ebenfalls die Erzeugung des Rücklichts beinhaltet;
• Figur 3 zweite Ausführungsform der Erfindung mit einer zweiter LED-Quelle zur Lichterzeugung für das Rücklicht des Zwergsignals;
• Figur 4 Ausführungsform einer LED-Lichtquellen-Anordnung für ein Zwergsignal mit zwei alternativen Platzierungen eines externen Lastwiderstandes;
• Figur 5 Ausführungsform einer LED-Lichtquellen-Anordnung für ein Zwergsignal mit einem Widerstandsring für die Wärmeabgabe.

The invention will be explained in more detail with reference to the drawing, for example. Showing:

• FIG. 1 Dwarf signal with the three signal terms;
• FIG. 2 first embodiment of the invention with a single LED source, which also includes the generation of the tail light;
• FIG. 3 second embodiment of the invention with a second LED source for generating light for the backlight of the dwarf signal;
• FIG. 4 Embodiment of an LED light source arrangement for a dwarf signal with two alternative placements of an external load resistor;
• FIG. 5 Embodiment of an LED light source arrangement for a dwarf signal with a resistance ring for heat dissipation.

FIG. 2 shows a first embodiment of an LED light source arrangement for a dwarf signal 50. The detailed representation of the optical paths includes the generation of the light for the tail lamp 44 via the interior mirror 5 and the mirror 9. This representation is thus for the upper light of the dwarf signal 50 provided in which a tail lamp 44 is provided with an obliquely arranged light beam. This bar is illuminated by the signal terms TRAVEL 42 and CAUTION 41. The tail lamp 44 is in the FIG. 2 merely symbolic and not constructive. The lower two lights 43 of the dwarf signal 50 do not need the return light generation, these are summarily shown on the right side by the reference numeral 8.

Aspherical lenses - here called collimator lens 2 are used to minimize aberrations. Instead of a complicated structure with several individual lenses, it is often sufficient to use an asphere. Collimators or collimator lenses 2 made of two materials, namely plastic and glass, are on the market. According to the spatial and geometric conditions within a dwarf signal 50, collimator lenses 2 are preferably used with an aperture angle of 5 ° to 15 °. The opening angle ω of an optical system is the angle formed by a point on the optical axis with the diameter of the entrance or exit pupil. Light emitted by the LED source 6 is collimated by the collimator lens 2 and exits inside the plexiglass tube 4. With the passage of the light through the frosted disc 10 results in a more homogeneous optical representation, ie a large-area light distribution on the front light 43. The light is previously passed through a front lens 19.

In the interior of Plexiglas tube 4, an interior mirror 5 is attached. At this inner mirror 5 light emerging from the collimator lens 2 is reflected by a lens 29. Behind this lens 29, a mirror 9 for returning the light to the tail lamp 44 of the dwarf signal 50 is arranged. The aforementioned interior mirror 5 may be formed as vapor-deposited aluminum surface "Al surface". Constructively, this inner mirror 5 can be divided into two parts, on the one hand a part relative to the shell of Plexiglas tube 4 and on the other hand for additional light rays for the front light orthogonal to the axis of Plexiglas tube. 4

The selected construction without reflective elements, in particular with the frosted disk and the collimator lens 2, can not form a basis for the occurrence of so-called phantom light.

The optical design for the lower front lights is the same structure, but eliminates components for the generation of the light for the tail light. This is in terms of the electrical part in the FIG. 2 represented by the reference numeral 8.

The electrical control of the LED source 6 is carried out from a control logic 11, which in turn is powered by the internal voltage conditioning 13 and a TRMS voltage measurement 12. This control logic 11 also controls a Energiebalancer 18, which is powered by the safety circuit 15 with energy. At this Energiebalancer 18, an external load resistor 20, usually a 40W resistor is connected. The control logic controls a total electrical load of 40W to maintain the interfaces or load specification with respect to the interlocking. This is necessary because the LED source 6 has a power consumption of around 2 to 3 watts compared to 18 to 20W for a light bulb. Likewise, about 2W for the electronics on the circuit board 26 (see. FIGS. 4 and 5 ). The bulb to be replaced, however, has a power consumption of 20W, so about 33-34W to consume. It should be noted that with a dwarf signal 50 always two lights are active. The dwarf signal 50 can be connected via a 4-wire or a 6-wire interface. According to the FIG. 2 a 6-wire interface 32 is provided. The components EMC protection 17 and input stage 16 are shown only for the sake of completeness, these have no function with respect to the aforementioned load balance.

The embodiment according to the FIG. 3 differs in terms of the generation of the tail light by a second embodiment, in which this tail light is generated by an additional second LED source 7. The further optical path to the tail light does not differ from the embodiment according to the FIG. 2 , On the other hand, the control logic 11 must now control the energy balancer 18 so that the sum of the loads through LED source 6 and LED source 7 and load resistor 20 again reaches 40W or the specified power value.

Both embodiments according to the Figures 2 and 3 can be placed on the Plexiglas tube 4 to increase the security levels, a light sensor 3. It actually detects if the LED source 6 is emitting light. The light sensor 3 is connected to a light monitoring unit 31. This transmits the detected LED state to the safety circuit 15. Here is known whether the relevant front light 43 is active or passive. From this, a fault can now be detected and, depending on the (legal or normative) security specifications, either a feedback to the signal box and / or the dwarf signal 50 can be switched to "dark". Signals switched to "dark" have the signal term HALT.

The LED source 6 is preferably part of an LED socket 1 including the Plexiglas tube 4. It is particularly advantageous to form the socket 1 plug-compatible with a light bulb. In this way, the assembly of the LED light source arrangement is considerably simplified.

The heat dissipation via the load resistor can therefore not be done inside the dwarf signal 50, because the heating of the life of the LED sources 6 and 7 is very considerably reduced. The significantly longer life of an LED source is a major advantage over incandescent lamps. For this reason, the heat removal must be done externally.

The FIGS. 4 and 5 show the constructive structure in a different view from the functional representation according to the Figures 2 and 3 , The in the Figures 2 and 3 are shown with the exception of the external load resistor 20, the LED sources 6, 7 and 8 and with the exception of the light sensor 3 on a circuit board 26 included. The printed circuit board 26 is fastened with a holder 25 in the dwarf signal 50. The connection to an interlocking via a terminal block 24, so the aforementioned 4-wire or 6-wire interface is routed through this terminal block 24.

1. i) Platzierung eines Lastwiderstandes 22 am Fuss 33 des Zwergsignals 50;
2. ii) Platzierung eines Lastwiderstandes 23 im das Zwergsignal 50 umgebenden Schotter 28.

In FIG. 4 two alternative placements of the load resistor 20 are shown:

1. i) placing a load resistor 22 at the foot 33 of the dwarf signal 50;
2. ii) placing a load resistor 23 in the ballast 28 surrounding the dwarf signal 50.

As in FIG. 5 shown, the load resistor 20 is formed as a load resistance ring 21 around the foot 33 of the dwarf signal 50.

For the simulation of the load other solutions are possible, for example, a feed back via a T-switching network. This (environmentally friendly) solution has the disadvantage that further installations are required for this.

List of reference numbers, glossary

1

LED base

2

collimator lens

3

light sensor

4

plexiglass tube

5

Interior mirror, vapor-deposited Al surface

6

first LED source, first LED for the upper lamp of the dwarf signal

7

second LED source, second LED for the upper lamp of the dwarf signal

8th

further LED sources, further LED for the lower two lights of the dwarf signal

9

Mirror for returning the light to the tail light of the dwarf signal

10

frosted glass

11

control logic

12

TRMS voltage measurement

13

Internal voltage conditioning

14

Luminous flux monitoring

15

safety circuit

16

doorstep

17

EMC protection

18

Energiebalancer

19

Front lens of the dwarf signal

20

External load resistance, e.g. 40W

21

External load resistance, e.g. 40W; designed as a load resistance ring

22

External load resistance, e.g. 40W; arranged at the foot of the dwarf signal

23

External load resistance, e.g. 40W; arranged in the gravel at the dwarf signal

24

terminal block

25

bracket

26

Printed circuit board with electronic components

27

Socket of the dwarf signal

28

gravel

29

lens

30

Monitoring function with safety-related failure reaction

31

Light monitoring unit

32

6-wire interface to the interlocking

33

Foot of the dwarf signal

40

Signal Term HALT

41

Signal concept RIDE WITH CAUTION, beginning or continuation of the journey; Immediately after the dwarf signal must be expected with an obstacle

42

Signal concept RIDE

43

Light, front light

44

Taillight

50

Zwergsignal

EMC

Electromagnetic compatibility

LED

light emitting diode

TRMS

True Root Mean Square

List of cited documents

1. [1] US 2004/0070519 A1
   «Compact light emitting diode retrofit lamp and method for traffic signal lights»
   Wu et al.
2. [2] AT 505 154 A4 2008-11-15
   «Optical Signaling Device»
   SWARCO FUTURIT
   Traffic Signal Systems Ges.mbH
   AT - 7343 Neutal

Claims (7)

1. LED light source arrangement for a dwarf signal (50) as a replacement for a light bulb arrangement, whereby

   - the dwarf signal (50) features a lamp (43) with a front lens (19) at its front panel; the lamp (43) is provided with light via a LED source (6) in a Plexiglas tube (4) with a LED base (1) and the light is transmitted by the LED source (6) via a collimating lens (2) and then being transmitted through a shaded slice (10) to the front lens (19) of the lamp (43),

   - a control logic (11) is provided in order to supply the LED source (6) with electrical energy,

   thereby characterized that
   the control logic (11) is connected with an energy balancer (18) for the replication of the energy consumption, whereby the energy balancer (18) supplies the energy that has not been used for the LED source (6) to the load resister (20), which is arranged outside the dwarf signal (50),
   and that
   for a tail lamp (44) arranged on the back side of the dwarf signal (50), transmitted light from the LED source (6) is conducted over an interior mirror (5), fixed to the Plexiglas tube (4), through a lens (29) and over a mirror (9) to the tail lamp (44) of the dwarf signal (50).
2. LED light source arrangement for a dwarf signal (50) as a replacement for a light bulb arrangement, whereby

   - the dwarf signal (50) features a lamp (43) with a front lens (19) at its front panel; the lamp (43) is provided with light via a LED source (6) in a Plexiglas tube (4) with a LED base (1) and the light is transmitted by the LED source (6) via a collimating lens (2) and then being transmitted through a shaded slice (10) to the front lens (19) of the lamp (43),

   - a control logic (11) is provided in order to supply the LED source (6) with electrical energy,

   thereby characterized that
   the control logic (11) is connected with an energy balancer (18) for the replication of the energy consumption, whereby the energy balancer (18) supplies the energy that has not been used for the LED source (6) to the load resister (20), which is arranged outside the dwarf signal (50),
   and that
   for a tail lamp (44) arranged on the back side of the dwarf signal (50), transmitted light from a second LED source (7) is conducted through a lens (29) over a mirror (9) to the tail lamp (44) of the dwarf signal (50).
3. LED light source arrangement according to claim 1 or 2,
   thereby characterized that
   for the observation of the light transmitted by the LED source (6) a light sensor (3) is provided, which is connected with a light observation device (31) that is connected with a safety shutdown (15) in the case of absence of transmitted light.
4. LED light source arrangement according to one of the claims 1 to 3
   thereby characterized that
   the external load resister (20) is applied as a load resister ring (21) around the foot (33) of the dwarf signal (50).
5. LED light source arrangement according to one of the claims 1 to 3,
   thereby characterized that
   the external load resister (20, 22) is applied to the foot (33) of the dwarf signal (50).
6. LED light source arrangement according to one of the claims 1 to 3,
   thereby characterized that
   the external load resister (23) is imbedded in the gravel (28) around the dwarf signal (50).
7. LED light source arrangement according to one of the claims 1 to 6,
   thereby characterized that
   the LED base (1) is combinable plug-compatible in the dwarf signal (50).

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