GB1567506A - Emergency lighting units and installations - Google Patents

Description

(54) IMPROVEMENTS RELATING TO EMERGENCY l lGHTING UNITS AND INSTALLATIONS (71) We, SUNBEAM LAMPS AND LIGHTING LIMITED, a British Company of Pontefract Lane. Leeds LS9 ()RZ, Yorkshire, do hereby declare the invention for which we pray that a patent may be granted, to us and the method by which it is to be performed to be particularly described in and by the following statement: This invention relatcs to emergency lighting units and installations.

Emergency lighting is now used widely in buildings such is cinemas, discotheques, hotels, hospitals and the like wherein, at times, there are lirge numbers of members ofthe public. The requirement for emergency lighting furthermore is expected to be applied in due course to an even wider field of public buildings such as public houses, offices, shops and so on.

As the name indicates, emergency lighting is a means whereby an area or position will be illuminated in the event of an emergency occurring. in particular the fails lure of the mains power supply. The emergency lighting may be arranged to indicate a position such as an exit or fire hose or the like, or it may serve simply as space lighting, for example in locations such as hospitals, where absence of lighting could be dangerous to life, even where the lighting may be lost for only a short period.

Basically, emergency lighting can be of two types, non-maintained and maintained.

In the maintained type, a light source is normally illuminated from the mains supply, and in the event of failure of the supply, the same light source is illuminated from an emergency supply. In the non-maintained type there are separate light sources, one of which is supplied from the mains supply, and the other of which is an emergency illumination source and only illuminated by the emergency supply when the mains supplied source fails.

In either case. when there is a mains failure, the emergency lighting is connected to a separate power source, usually one or more d.c. batteries, for the illumination of the lighting.

It will be understood that the maintenance and functioning of emergency lighting is very important, and indeed fire officers make periodic checks on all emergency lighting installations to ensure that they are in good working order. Conventionally, each lighting unit of a non-maintained emergency lighting installation is provided at least with one indicator lamp, usually green, through which a small current is passed; this current is also passed through the emergency lamp in the unit and anyone inspecting the unit and seeing the small green monitor lamp on, will know that the filament of the emergency lamp is in order.

It is also usual to provide a red monitor lamp which, when illuminated, indicates that the charging circuit for the battery or batteries is operating. In a maintained system it is of course not necessary to provide the green monitor lamp.

Those monitor lamps, although useful do not guarantee that the emergency lighting will however work in the event of a mains failure. The only method at present available for checking this is to simulate a mains failure by switching the power off at the mains. Apart from the fact that this testing procedure is inconvenient, it is not something which the fire authorities recommend and it could interfere with the sub-circuits of the emergency lighting units and could impair their performance.

The present invention seeks to provide an emergency lighting unit or installation, the testing of the operative condition of which can be effected easily and conclusively, without recourse having to be had to shutting off the mains supply.

According to the invention there is provided an emergency lighting unit provided with a receiver which is actuable by signals which can be transmitted through space, said receiver being connected to a control circuit of the-emergency lighting unit so that upon receipt of signals transmitted through space, and the resultant operation of the control circuit, the effect of a mains failure is simulated.

It will be appreciated that the person wishing to test the unit will have an appropriate transmitter for supplying the signals to the receiver, In practice, the transmitter and receiver will be selected so that the control circuit will not be operated spuriously.

Conveniently, the transmitter may be a battery torch which limits a narrow and higher than average power beam of light, and the receiver may be a photo-cell device, and the control circuit may include a transistor which is made to cut off thereby causing a relay to drop out when the photo-cell device receives transmitted light signals.

In a modified form of the receiver, it includes a re-triggerable device and the transmitter in this case would be adapted to provide signals repeating at a higher frequency than the frequency of the retriggerable device in order to ensure that the device remains triggered to maintain the transistor cut-off when the transmitted signals are received by the receiver, The invention can be applied to nonmaintained and maintained units and units embodying the auxiliary power source or not; normally the receiver will be embodied in a casing of the unit. It is not necessary that this be so, however, and in an emergency lighting installation involving a number of units, the receivers for the units may be located remote from the units.

In another form of the invention the receiver is for receiving and being operated by magnetic signals, thus, the receiver may be a reed switch which is operable for example by means of an electro or permanent magnet carried by the person who tests the equipment.

In all cases, when the condition of mains failure is simulated, the appropriate emergency lighting unit will operate, indicating that it is functioning correctly.

Emergency lighting units invariably are arranged at a high level, and the present invention provides a means whereby a person with an appropriate transmitter, e.g.

a torch or electro-magnet can test the units without having to shut down the mains supply and without, in the case of the preferred embodiments, having to climb up ladders to the units to inspect them.

Embodiments of the present invention will now be described by way of example, with reference to the accompanying drawings wherein: Figure 1 is a circuit diagram of a nonmaintained emergency lighting unit, and also shows a modification; and Figure 2 is a diagrammatic side view showing the receiver of the circuit of Figure 1.

Referring to the drawings, in Figure 1 there is shown the circuit for a nonmaintained emergency lighting unit having a lighting tube T of the fluorescent type. The circuit is supplied from AC mains through a transformer, and the AC voltage is rectified by a full wave rectifier D1-D4 to provide DC at rails R1 and R2. The tube T has conventional control gear G. The circuit includes relay contacts RL1 which are operated by relay RL. In the normal operation of the unit, the casing of which is indicated in dotted lines, the relay RL is maintained energised which keeps contacts RL1 in the dotted line position shown in which supply of power to tube T is cut off, and the tube T is off.In the event that relay RL is deenergised and drops out, for example in an emergency when there is a mains failure, contacts RL1 move to the full line position shown and an auxiliary power supply in the form of battery B either in the unit or at a remote location is connected to the tube T through new closed contacts RL1 and tube T is switched on.

In accordance with the embodiment of the invention illustrated in Figure 1, a circuit comprising Zener diode 1 and resistor 3 connected in series, and capacitor 2 in parallel with resistor 3, is connected between rails R1 and R2. A transistor 6 is connected between relay RL and rail R2 as shown, whilst a diode 8 is connected across RL in order to suppress reverse voltage spike caused by the energy in the relay coil collapsing so that no damage can be caused to the active components by such a spike.

The base voltage of transistor 6 is set by a resistor 4 connected between the base of transistor 6 and the junction between diode 1 and resistor 3.

A receiver in the form of a light energy detector switch 5 is connected between the base and emitter of transistor 6 such that when appropriate signals are received by detector 5, in particular signals in the form of a continuous white light spectrum, the detector 5 decreases the voltage at the base of transistor 6 causing same to cut off. The cutting off of transistor 6 causes relay RL to de-energise, diode 8 suppressing the reverse voltage spike as above-mentioned, and the relay contacts RL1 are now placed in the full line position shown connecting tube T to the auxiliary power supply B and the tube T is illuminated indicating that the emergency lighting unit is in good working order. If tube T fails to illuminate when the unit is subjected to this testing, then this will indicate a fault in the unit requiring investigation.The production of continuous white light spectrum can be produced by a higher than average power torch.

The detector 5 is shown diagrammatically in Figure 2. and the light sensitive device l() thereof is housed in housing 12 having an insert 14 acting as a light guide, such tli;it only when light energy is aimed directly at the insert 14 will the device 10 be activated.

The housing 12 can be set such that incident light will not cause spurious activation oi the circuit. The receiver can be mounted on or adjacent the emergency lighting unit (Luminaire) and in the example shown in Figure 2, the housing l() is provided with a threaded sleeve 16 ímd a lixing nut lX and washer 19 for the comleclioll ol the receiver to an existing lightiiig unit casing.The electrical connection lculds extending from device 10 are indicalc.l l'y iiumeral 20.

In a modified arrangement, a further device 9 is hlcluded in the control circuit controlling the operation of relay RL in the event of simulated mains failure. This device is hldic;ltcd in dotted lines in Figure 1 and is indicited by numeral 9. Device 9 is re-triggerible one shot device which is caused to opcliltc when the energy detector 5 operates.For this modification, it is necessary to use a specially modified trans mittcr which supplies pulses to detector 5 which are at a frequency greater than that of the re-triggerable one shot 9 so that when said pulses fall on detector 5, re-triggerable one shot 9 is caused continuously to conduct as is device 5 thereby lowering the voltage applied to the base of transistor 6 and thereby causing relay RL to drop out with the effect as above described of bringing on the emergency lighting tube T.The advantage of this particular modification is that only a specially adapted transmitter will cause operation of the control circuit to put the emergency lighting unit into simulated mains failure condition, and thus the position of the detector 5 relative to incident light is not so critical as in the case of the arrangement already described wherein device 9 is not provided.

In a modified form of the invention, the receiver switch a magnetically operated. It may be for example, a reed switch which is normally open, but which closes, with the effect of bringing on the tube T as above described, when a magnetic field is impressed thereon. The magnetic field can be impressed by means of a permanent or electro-magnet.

In another arrangement, there is a magnetically actuated device in addition to a light sensitive device, and they are connected in the control circuit such that both must be actuated for the effect of a mains failure to be simulated.

Furthermore several types of receiver may be used in combination in order to make it as difficult as possible for anyone other than authorised personnel to operate the testing of the equipment.

The invention provides the advantage that a person whose joh it is to test emergency lighting units can test them cluickly and effectively simply by carrying a light transmitter as a means providing Illgnetic or other signals, when the units ire equipped in accordance with the present invention, without having to remove the mains supply to each unit by manually operating a switch of each unit or by physically removing a fuse of each unit.

WHAT WE CLAIM IS: 1. An emergency lighting unit provided with a receiver which is actuable by signals which can be transmitted through space, said receiver being connected to a control circuit of the emergency lighting unit so that upon receipt of signals transmitted through space, and the resultant operation of the control circuit, the effect of a mains failure is simulated.

2. An emergency lighting unit according to claim 1, wherein the said receiver includes a light sensitive device operable by means of a torch.

3. An emergency lighting unit according to claim 2, wherein the light sensitive device is a photocell actuable by means of a narrow beam, higher than average power torch.

4. An emergency lighting unit according to claim 2 or 3, wherein the light sensitive device is connected to a re-triggerable device which controls the operation of the control circuit such that it must be triggered before the effect of a mains failure is simulated, so that to maintain said effect of mains failure simulated, the light sensitive device must be operated at a frequency higher than the triggering frequency of the re-triggerable device.

5. An emergency lighting unit according to any preceding claim, wherein the receiver includes a magnetically actuated device, actuable by a magnetic field, and where the magnetically actuated device is in addition to said light sensitive device, they are connected in the control circuit such that both must be actuated for the effect of a mains failure to be simulated.

6. An emergency lighting unit according to any preceding claims wherein the unit is of the non-maintained type.

7. An emergency lighting unit substantially as hereinbefore described with refer

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (8)

**WARNING** start of CLMS field may overlap end of DESC **. indicate a fault in the unit requiring investigation. The production of continuous white light spectrum can be produced by a higher than average power torch. The detector 5 is shown diagrammatically in Figure 2. and the light sensitive device l() thereof is housed in housing 12 having an insert 14 acting as a light guide, such tli;it only when light energy is aimed directly at the insert 14 will the device 10 be activated. The housing 12 can be set such that incident light will not cause spurious activation oi the circuit. The receiver can be mounted on or adjacent the emergency lighting unit (Luminaire) and in the example shown in Figure 2, the housing l() is provided with a threaded sleeve 16 ímd a lixing nut lX and washer 19 for the comleclioll ol the receiver to an existing lightiiig unit casing.The electrical connection lculds extending from device 10 are indicalc.l l'y iiumeral 20. In a modified arrangement, a further device 9 is hlcluded in the control circuit controlling the operation of relay RL in the event of simulated mains failure. This device is hldic;ltcd in dotted lines in Figure 1 and is indicited by numeral 9. Device 9 is re-triggerible one shot device which is caused to opcliltc when the energy detector 5 operates.For this modification, it is necessary to use a specially modified trans mittcr which supplies pulses to detector 5 which are at a frequency greater than that of the re-triggerable one shot 9 so that when said pulses fall on detector 5, re-triggerable one shot 9 is caused continuously to conduct as is device 5 thereby lowering the voltage applied to the base of transistor 6 and thereby causing relay RL to drop out with the effect as above described of bringing on the emergency lighting tube T.The advantage of this particular modification is that only a specially adapted transmitter will cause operation of the control circuit to put the emergency lighting unit into simulated mains failure condition, and thus the position of the detector 5 relative to incident light is not so critical as in the case of the arrangement already described wherein device 9 is not provided. In a modified form of the invention, the receiver switch a magnetically operated. It may be for example, a reed switch which is normally open, but which closes, with the effect of bringing on the tube T as above described, when a magnetic field is impressed thereon. The magnetic field can be impressed by means of a permanent or electro-magnet. In another arrangement, there is a magnetically actuated device in addition to a light sensitive device, and they are connected in the control circuit such that both must be actuated for the effect of a mains failure to be simulated. Furthermore several types of receiver may be used in combination in order to make it as difficult as possible for anyone other than authorised personnel to operate the testing of the equipment. The invention provides the advantage that a person whose joh it is to test emergency lighting units can test them cluickly and effectively simply by carrying a light transmitter as a means providing Illgnetic or other signals, when the units ire equipped in accordance with the present invention, without having to remove the mains supply to each unit by manually operating a switch of each unit or by physically removing a fuse of each unit. WHAT WE CLAIM IS:

1. An emergency lighting unit provided with a receiver which is actuable by signals which can be transmitted through space, said receiver being connected to a control circuit of the emergency lighting unit so that upon receipt of signals transmitted through space, and the resultant operation of the control circuit, the effect of a mains failure is simulated.

2. An emergency lighting unit according to claim 1, wherein the said receiver includes a light sensitive device operable by means of a torch.

3. An emergency lighting unit according to claim 2, wherein the light sensitive device is a photocell actuable by means of a narrow beam, higher than average power torch.

4. An emergency lighting unit according to claim 2 or 3, wherein the light sensitive device is connected to a re-triggerable device which controls the operation of the control circuit such that it must be triggered before the effect of a mains failure is simulated, so that to maintain said effect of mains failure simulated, the light sensitive device must be operated at a frequency higher than the triggering frequency of the re-triggerable device.

5. An emergency lighting unit according to any preceding claim, wherein the receiver includes a magnetically actuated device, actuable by a magnetic field, and where the magnetically actuated device is in addition to said light sensitive device, they are connected in the control circuit such that both must be actuated for the effect of a mains failure to be simulated.

6. An emergency lighting unit according to any preceding claims wherein the unit is of the non-maintained type.

7. An emergency lighting unit substantially as hereinbefore described with refer

ence to the accompanying drawings.

8. An emergency lighting unit according to any one of the preceding claims in combination with a transmitter capable of operating said receiver.