Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates to a flashing light appa-
ratus, and especially to that kind of apparatus, which comprises
a plurality of flashing light units. These units may be connect-
ed in series, parallel or branched. Each unit is arranged to
give a short flash in a predetermined time slot. All time slots
allotted to a plurality of these units are so chosen that the
first unit is first activated, and after a predetermined time
period or immediately thereafter, the second unit is activated,
etc. The generated flashing lights from all units in a chain
thus give the impression of a "travelling flash". Such a flash-
ing light apparatus may be used for traffic ~urposes to give the
road user a visual indication of how a working site in the road
can be passed, in the ship yard as an indication of the emergency
exit, etc.
Previously known in the art are a large number of
different flashing light apparatuses and among those having the
features mentioned above it is common to have one master unit and
a plurality of slave units connected thereto. The master unit
is usually constructed in a complicated manner while the slave
units are more simply constructed. The master unit generates a
plurality of time separated control pulses, one for each slave
unit, in order to aciivate each slave unit within its own time
slot. Such an arrangement has the disadvantage that a cable
breakdown close to the master unit causes the ~hole apparatus
to become inactive. Further it it common to arrange the power
supply to all s~ave units through,the master unit, and a break-
down in the power supply will surely cause the apparatus to
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become inactive.
In accordance with the present invention, there is
provided a flashing light apparatus including a plurality of
flashing light units forming a chain of light units in which each
light unit produces a flash of light in a predetermined time slot
different from the time slot associated with adjacent light units
in the chain, wherein each light unit comprises: an input terminal
for receiving control signals from a preceding light unit in the
chain of light units; an oscillator for producing pulses at a
predetermined rate; a multivibrator circuit for producing output
signals; switching means for selectively connecting said multi-
vibrator to receive pulses from said oscillator in a first mode
and control signals from said input terminal in a second mode;
control circuit means responsive to the signals at said input
terminal for controlling the operation of said switching means;
flashing means responsive to an output signal from said multi-
vibrator to produce a flash of light; and an output terminal
adapted to provide output signals from said multivibrator circuit
as control signals to a subsequent light unit in the chain.
The main object of the present invention is to provide
a fla5hing light apparatus in which all flashing light units are
equally constructed, which means that the master unit is identical
to the slave unit. This object will reduce the production cost
and simplify the storage system.
A second object of the present invention is to provide
a flashing light apparatus in which each and every flashing light
unit has its own power supply.
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This object has the advantage that a cable breakdown
anywhere along the line of a chain of flashing light units allots
automatically one slave unit to become a master unit, and the
complete flashing light apparatus i6 still operative.
A further object of the present invention is to provide
a flashing light unit having an interior power supply, an oscilla-
tor, a eontrol circuit, a switching means, a monostable multi-
vibratox and a flashing light generating means.
So that further objects and advantages related to this
invention will appear, a preferred embodiment, having the novel
features of the present invention, will be described with referenee
to and illustrated in the aeeompanying drawing in whieh
Figure 1 shows partially in bloek a circuit of a
flashing light unit, a plurality of which form the flashing light
apparatus,
Figure 2 shows three units aeeording to Figure 1 connee-
ted in series and thus forming the flashing light apparatus and
Figure 3 shows a eireuit diagram of the bloek eontrol
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circuit shown in Figure 1.
The present invention relates to a flashing light
apparatus, and especially to that kind of apparatus, which com-
prises of a plurality of flashing light units. These units may
be connected in series, parallel or branched. Each unit is
arranged to give a short flash in a predetermined time slot.
All time slots allotted to a plurality of these units are so
chosen that the first unit is first activated, and after a pre-
determined time period or immediately thereafter, the second unit
is activated, etc. The generated flashing lights from a chain
of units give the impression of a "travelling flash". Such a
flashing light apparatus may be used for traffic purposes, to
give the road user a visual indication of how a working site in
the road can be passed, in the ship yard as an indication of
the emergency exit, etc.
In Figure 1 is shown partially in block diagram a pre-
ferred circuit used in the flashing light unit and the dashed
frame encircles an individual unit. Each flashing light unit 1
contains a gate or a switching means 2, capable of being switched
into one of two positions. The first position (an uninfluenced
state) is defined by a connection between the fixed contact 3
and the movable contact 4, and the other position (influenced
by a control signal) is defined by a connection between the
fixed contact 5 and the movable contact 4. The gate 2 consists
preferably of a semiconductive switching arrangement. Fixed con-
tact 3 of the gate 2 is connected to the output terminal 6 from
a free running oscillator 7 which is arranged, for example, to
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give an output pulse every other second. This output pulse is
fed, when the gate 2 is switched into its first position, to
the input terminal 9 of a monostable multivibrator 8. The mono-
stable multivibrator generates at its output terminal 10 pulses
with a definite duration, for example a duration of 0.3 sec.
and with a repetition frequency equal to that of the oscillator.
The signal occurring on output terminal 10 is connected to an
amplifier 11 which activates a light bulb 12, which gives a
flash during the time of the pulse duration. The signal from
the multivibrator 8 is also connected to an output terminal 13
for the flashing light unit 1, from which the signal, as described
later, can be connected to an adjacent flashing light unit in
the chain (see Figure 2).
Each flashing light unit is also provided with an input
terminal 14. The input terminal 14 and the output terminal 13 may
have the form of connecting means arranged onto the cover of the
unit. The input terminal 14 is connected by a cable 15 to the
fixed contact 5 of the gate 2 and an external signal, which
occurs at the terminal 14, will thus be connected to the fixed
contact 5- The external signal to the input terminal 14 is
also fed via a cable 16 to a control circuit 17 which is arranged
to receive the signal and further to send it, via its own out-
put terminal 18, to the gate 2 as a switch-over signal. This
signal is connected to input terminal 19 for the gate 2. As soon
as the gate 2 receives this switch-over signal, the movable con-
tact 4 is switched over so that a path is formed over the fixed
contact 5 and the movable contact 4 to the multivibrator 8. The
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connection to the oscillator 7 is thus broken. The control cir-
cuit 17 is arranged to delay the pulse on the output terminal 18
in proportion to that appearing on the input terminal 14 and to
keep the gate 2 in its switched-over position, for example during
4 seconds, if one single moving flash of light is desired.
If a series of moving flashes of lights is desired the
delay time for the gate 2 must be at least equal to the time
between two flashes by the master unit, that is the first unit
in the chain. ~he delay time between incoming and outgoing
signals in the control circuit is adjustable and dependent upon
how the flashes are to be produced by each unit. A necessary
delay is obtained if the monostable multivibrator 8 is triggered
by the trailing edge of a square wave pulse and the control cir-
cuit 17 is triggered by the leading edge of the pulse. It is
evident that the leading edge and the trailing edge of the pulse
are received at the output terminal 13.
Figure 2 shows a chain with only three flashing light
units of the above described type, which are given the reference
numerals 1, 1' and 1" respectively. The flashing light unit 1
has its output terminal 13 from its multivibrator 8 connected,
via a cable 20, to the input terminal 14' of an adjacent flash-
ing light unit 1', and this flashing light unit has its output
terminal 13' connected via a cable 21, to the input terminal 14"
of the adjacent flashing ligh$ unit 1". The flashing light unit
1 has its gate 2 unactivated, since a signal is not being fed to
its input terminal (14 in Figure 1) and thus its oscillator 7
will continuously send signals via its ~ate 2 to its multivibrator
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8, which partly produces flashing of its lamp 12 and partly sends
an output signal to activate the input terminal 14" of the follow-
ing flashing light unit l'. The flashing light unit l' will
thus have its gate 2 in the second position, and the signal
triggering this flashing light unit l' is the signal generated
by oscillator 7 and reshaped in multivibrator 8 in the flashing
light unit l. The same is valid for all further flashing light
units in the chain, for example the flashing light unit l".
Through the mentioned signal delay in circuit 17 or utilization
of leading and trailing edges of the signals, the different lamps
will cause a flash as soon as the adjacent lamp has gone out and
a moving flash of light is provided along the chain.
Since all flashing light units are identical, any
flashing light unit can form a controlling master unit for the
following flashing light units., w.hich automatically have their
oscillators switched off and thus form slave units.
The current supply is not shown in the illustrated
embodiment in the drawing, but can be achieved either through
interior batteries in every ~lashing light unit or from an -
exterior current source, in w.hich the connection of flashing
light units to a chain is done by a three wired cable, wherein
two wires make a current feeding wire and one wire makes a signal
transporting wire.
A master light unit, for example, the unit l in
Figure 2 can also control side chains, which is indicated by the
wire 22. If a chain would be damaged and for example the wire 20
in Figure 2 would be exposed to an interruption in the signal wire,
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the flashing light unit 1' will become a master unit for all the
following light units and the first light unit 1 in the chain will
blink or flash independently of the other light units, and the
desired function is essentially maintained. The lamp 12, is
preferably made by a conventional bulb, but can also consist of,
for example, a discharge lamp.
It should be noted that the multivibrator 8 may be a
bistable multivibrator or a monostable multivibrator. The
oscillator 7 may be free running or may be controlled.
1~ Figure 3 shows an arrangement of the controlling circuit
17 in Figure 1.
The input signal on line 14 is connected to a capaci-
tance Cl. The signal is inverted in an inverting device Dl, and
fed through a diode D2. A capacitance C2 and a resistance Rl
form the input delay for the amplifier Al, the output of which
is connected to the gate arrangement 2.
The invention is not restricted to the shown embodiment
but may be modified within the scope of the succeeding claims.
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