EP0637195A1

EP0637195A1 - A device for controlling and managing lamp functioning state

Info

Publication number: EP0637195A1
Application number: EP94830206A
Authority: EP
Inventors: Piero Cecchini; Alberto Grossi
Original assignee: Sa Metas
Current assignee: Sa Metas
Priority date: 1993-07-30
Filing date: 1994-04-29
Publication date: 1995-02-01
Also published as: EP0711498B1; ATE160253T1; DE69406796D1; ITBO930339A0; EP0711498A1; IT1264183B1; WO1995004446A1; DE69406796T2; ITBO930339A1; AU7387194A; ES2113120T3

Abstract

The microprocessor device is characterised in that it exploits guided waves to send signals between a control console and a series of tranmitters serving to identify a working state of a single lamp in a series of lamps. The signals identify a phase angle between lamp current and voltage, specifying a type of fault on the basis of the angle identified. A permanent memory associated to the microprocessor manages the entire process.

Description

The invention relates to a device for controlling and managing lamp functioning state, comprising a microprocessor unit and a waveguide transmission system.
It is well known that in the field of public streetlighting systems, or wherever a series of lamps is required, remote control of the lighting network is required, as well as - given the vast areas often illuminated by such networked systems - a trouble-shooting system to report failure and location of a single lamp and give reasons (such as a short-circuit or loss of gas) for such failure.
Progress in the area of modern industrial electronics has provided intelligent command and control systems able to obviate the above problems, but the task of adapting old existing networked systems to new intelligent electronic methods laborious and ultimately uneconomical.
Nevertheless, there exist examples of such adaptations, which make use of microprocessor apparatus but are still not able to identify exactly which lamp has failed and what kind of failure has occurred. Also, they are not able to offer direct management of every single lamp in the network: for example, not every lamp can be singly lit, nor can certain lamps be turned on and others not.
All of the above systems exploit the waveguide criterion, using the same electrical supply line both to send and to receive the signals, but are not sufficiently capillary and developed in terms of system intelligence (even where the microprocessor is used to its full extent) to be reliable, rapid and economical.
To sum up, prior art disclosures exploiting the waveguide system, use a microprocessor so that the system is intelligent, able to manage a lamp system, but cannot identify a single faulty lamp, nor the nature of a fault: finally, they do not provide absolute system reliability for the individual users (the lamps themselves).
A solution to the above problems has been proposed, in which the whole range of service functions relative to the remote control of a lamp system are integrated in a single multi-functional circuitry installed both on each lamp-post and on the central command and control unit managing the whole system. Waveguide technology was used so that the same means used to supply the lamps with current could also be exploited for the above-mentioned service functions. The whole system would therefore be controlled both centrally and peripherally by microprocessor circuit units.
The present invention adopts the above technology as well as other parameters (which will be better explained hereinbelow) in order to obviate the above-described drawbacks in the pior art and provide a control and management device for lamp circuits, which integrates all of the circuitry relative to the control functions of the lamps, in which the said circuitry is entirely microprocessoried both centrally and peripherally with the aim of lowering realization costs and rendering the management of the system more precise, more direct and easier to operate.
This and other aims besides are attained by the microprocessor device for control and management of lamps of the invention, as it is characterized in the claims that follow.
Further characteristics and advantages of the present invention will better emerge from the detailed description that follows, of an embodiment of the invention, illustrated in the form of a non-limiting example in the accompanying drawings, in which:

figure 1 is a block diagram of the transmitting and receiving units of the device;
figure two shows a plurality of identifying situations of the state of a lamp according to the invention.

With reference to the diagrams and in particular to figure 1, the three squares evidenced by broken lines refer to the following: 1 denotes the part of the block diagram relating to the circuitry of the waveguide device transmitter; 2 the part of the diagram relating to the waveguide transreceiver interface; and 3 a block diagram relating to the device receiver.
Taking first the transmitter circuitry 1, 2 denotes the waveguide transreceiver interface, more completely illustrated in square 2, while 3 (also represented in an independent square) denotes a single-chip microprocessor managing the transmitter unit.
The microprocessor is provided with an EEPROM permanent memory 4 memorizing transmitter parameters and code. The permanent memory 4 memorizes the identifying number of the transmitter, assigning it a code of from 1 to 128, as well as the transmitter functional parameters, that is, the various timings, the threshold values of the phase displacement angle, the number of lamps, and so on.
Since the transmitter can be identified through its code, the lamp it is associated to (with its various parameters) can also be identified. The parameters can be modified to adapt the transmitter to the various kinds of lamps and diverse transmitter application conditions.
The voltage zero is read by a sensor block 5 constituted by a logic gate comparator which compares the actual voltage with zero voltage and further checks that the voltage does not fall below a certain minimum value.
Subsequently, a circuit block 6 effects a circuit check of the current zero, verifying when that occurs and also ensuring that the current does not fall below a predetermined minimum threshold and cause the microprocessor 3 to signal a halt to the lamp supply circuit. Said circuit block 6 is constituted by a logic gate comparator which compares the current value with a zero value.
Block 7 denotes an electronic switch consisting of a piloted transistor serving to control the on/off operations of the lamp, which the device of the invention is connected to through connection 7a.
With regard to the waveguide transceiver interface 2, it can be seen how the 220 volt supply is used through a network connection circuit 9 constituted by a circuit section consisting of transistors and a coil.
Downstream of the network connection circuit 9 is a corresponding transmitter-receiver circuit 10, constituted by a circuit filter 11.
Downstream of the transmitter-receiver circuit 10 is situated a tone-decoding circuit 12, which by means of a PLL circuit intercepts a signal of a certain frequency in the envisaged period and takes on the assigned value.
The uncoded signal leaving the decoder 12 is then sent, through line 10a, to the local microprocessor 13 of the microprocessor 3 set on the lamp which is to be checked.
Likewise the network supply is guaranteed through line 9a, which supplies the supply circuit of the microprocessor 3, represented by circuit block 15.
The local microprocessor 13 coupled to line 10a, and a communication interface 14 serving for connection with a central data transmission system (through a line 16), are situated on the microprocessor 3.
Figure 2 shows the different possible functioning conditions of a lamp 19, subdivided into 2a, 2b, 2c and 2d according to the state of the lamp.
2a shows normal functioning situation, wherein the lamp is supplied through clamps 21a and 21b; a rephasing condensor 20 being provided, as well as a traditional-type reactor 17 and an ignition device for fluorescent lamps, denoted by 18.
The lamps described and illustrated are mercury or sodium vapour lamps 19. The difference between the two types of lamp consists in the fact that for sodium vapour lamps no ignition system is present.
2b shows a lamp 19 where the rephasing condensor is switched off and therefore not illustrated.
2c illustrates a classic situation in which the lamp 19 is in short circuit, as the clamps 19a and 19b are directly connected one to another.
Finally, 2d illustrates a lamp 19, switched off due to a defective ignition 18.
The functioning of the system will now be decribed, in order to evidence the control characteristics.
First it must be underlined that the device uses the waveguide system; that is, a system in which a signal is transmitted in frequency by a transmitter, travelling on a normal electrical line, and which is received by a receiver when the network is enabled, and hooked up to the functioning frequency decided on during its design. In essence, there is superposition of a frequency signal on the grid electric supply, which in Italy is of 50Hz.
When the signal, travelling on a normal electric wire, reaches the desired point, the receiver couples into the network, hooks the signal, decodes and interprets it.
This being established, it can be evidenced how the device, using the waveguide system, can not only check the lamps, but also manage them singly, as it reads the phase angle between voltage and current.
With reference to figure 2, the identification and thus the determination of the various functioning states happens as has already been described, exploiting the measurement of the phase angle between voltage and current, actuated by comparison circuits 5 and 6.
This criterion is very important, since the phase angle between the current and voltage is independent of the type and power of the lamp and thus cannot place constraints or limitations and is not therefore influenced by a variation in the supply voltage, while it is very characteristic of the state of the lamp.
This phase angle is determined by measuring the time interval between the passage through zero of the voltage, that is the negative-positive transition, and the current passage through zero, that is the always-negative-positive transition.
At 50 Hz the period corresponds to about 20ms, equivalent to 360 degrees.
With reference to the situations of figure 2, the following can be specified.
In relation to situation 2a, in normal lamp conditions the phase angle must oscillate between 20 degrees and 25 degrees.
In relation to situation 2b, where the rephasing condensor 20 is broken, the angle to be read must oscillate between 50 degrees and 75 degrees.
In situation 2c, on the other hand, where the lamp 19 is in short circuit, the angle must oscillate between 77 degrees and 86 degrees.
The situation in 2d, that is, with the lamp broken, the angle must oscillate between 260 degrees and 270 degrees, while obviously if the connection with the lamp is broken there is no current at all.
The sensing is done by means of comparators 5 and 6, which send the signal to the processor 3 which processes the corresponding situation in order to determine the angle range and to see what situation the lamp 19 is in, according to the memory.
Obviously each transmitter 1 is identifiable by a code going from 1 to 128, and a specific easily-interpretable communication protocol is proevided between the central unit, which can be situated at distance from the lamp series line and the single processors 3 and 13 present on each lamp-post.
In a connection between switchboard and transmitter 1, the protocol is such that the first byte identifies the transmitter while the second byte serves to command the switch 7 to turn the lamp on or off, or group of lamps, in the case of transmitters controlling more than one lamp.
In an opposite situation, a connection from the transmitter 1 to the switchboard, the first byte identifies the transmitter 1 code and the second byte indicates the lamp situation.
Obviously the maximum possible number of lamps is 128, that being the maximum number of transmitters installable. As each transmitter controls more than one lamp, more than 128 lamps can be controlled and managed.
In a lamp network several electric supply panels are needed, each having a control switchboard installed allowing data to be collected from the single lamps 19.
Now dialogue is between the transmitters 1 and the receivers 2 by a waveguide signal transmission which exploits the supply line 8a-9a of the electricity grid supplying the lamps.
Data on the situations of the single lamps and the turn on-off command for each lamp are read by each single transmitter/ receiver 1 and 2 on a local device, and are then sent to the central unit of the system centralizing panel through a modem or another transmission device.
At predetermined intervals the remote central unit, not illustrated in the figures, calls the single transmitters, which, having received the signal on its receiver 2, send their own identification code and the state of their own lamp back. It is possible then to activate or deactivate each lamp centrally, simply by using the on/off switch 7.
With regard to waveguide systems, considering a quartz emitting 3.58 MHz it is possible to send a 112 KHz signal modulated with a binary code to tranmit the on/off signal. The modulation is on request, that is, of the ASK type with the MANCHESTER codification.
All the information relating to the state of the lamp is contained in one bit.
The 112 KHz transmitter is present in the transceiver 2 circuit interface of the transmitter 10 and is commanded by the microcontroller, which is in effect the on/off switch 1 and 2.
The filter 11 frequency-filters such signals and decode them through a tone-decoding operation performed by the decoding circuit 12.
The microprocessor 3 and the microprocessor 13 permit of interfacing between the various modules 1, 2 and 3, actuate the decoding of the received waveguide signals, being provided with resident firmware, and participate, together with the comparators 5 and 6, in verifying that the lamp supply voltage is present and is not below a predetermined value, in order to gurantee and optimal management of the communication and modulation of the waveguide transmission carrier.
Using the electricity grid line and exploiting the waveguide criterion, the voltage-current phase angle signal of each lamp is sent, and according to the measurement of the angle, a lamp state situation is established and an actuation command is transmitted.
Thus, by exploiting the known art relating to guided waves, and the novelty of the voltage-current phase angle measurement, through actuator circuit modules, direct control of each single lamp is made possible. The system is economical and, in terms of circuitry, simple, and allows for remote control independently of the state of the individual lamp.

Claims

A microprocessor device for controlling and managing lamps, comprising a microprocessor unit and a waveguide transmission system, characterised in that transmission modules a said waveguide system are provided with comparator circuits for a measurement of a phase angle between a voltage and a current.
A microprocessor device as in claim 1, characterised in that the comparator circuits are constituted by logic gate comparators which measure a voltahge and a current passage through zero.
A microprocessor device as in claim 1, characterised in that the phase angle measurement actuated by the comparators catalogues a lamp state in certain ranges by means of tables existing in a memory associated to the microprocessor maanaging each transmitter.
A microprocessor device as in claim 1, characterised in that the tables refer to a range of between 20 degrees and 270 degrees, within which range a plurality of lamp functioning states can be identified.