GB2078413A

GB2078413A - Intruder detecting systems

Info

Publication number: GB2078413A
Application number: GB8018121A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-06-03
Filing date: 1980-06-03
Publication date: 1982-01-06

Abstract

Lighting apparatus 16 is switched on by a sensing means 10, 11 such as an ultrasonic or microwave device, adapted to detect movement of a person or object within a monitored space. A light sensor 18 is also provided and connected to enable the switching means 15 when the ambient light falls to a predetermined level.

Description

SPECIFICATION Improvements in or relating to lighting apparatus This invention relates to lighting apparatus and in particular to apparatus which can automatically control the switching of a lighting apparatus.

According to the present invention there is provided apparatus for controlling the application of electrical energy to a light comprising motion sensing means for sensing movement of an object within a given range thereof, and switching means which is arranged to be actuated in response to said sensing means sensing said movement, said switching means being for connection in circuit with a light whereby when said swiching means is actuated electrical energy is supplied to said light.

The sensing means may comprises an ultrasonic sensing means. The ultrasonic sensing means may comprise an ultrasonic transmitter and an ultrasonic receiver, said ultrasonic receiver being arranged to detect amplitude modulation of the received signal and to produce an output signal the level of which is high or low depending upon the detected modulation.

Alternatively the sensing means may comprise a microwave sensing means. The microwave sensing means may include a microwave Doppler unit which transmits microwave energy and detects any doppler shift in the reflected signal, said unit being arranged to produce an output signal which is high or low depending upon whether the received signal includes a frequency shifted component.

The switching means may include a relay.

The apparatus may include light sensing means for sensing the ambient light intensity, the light sensing means being gated with said sensing means and being arranged to actuate the switching means when the ambient light has a predetermined intensity.

As a further alternative the sensing means may comprise an infra-red sensing means.

The invention will be described now by way of example only with particular reference to the accompanying drawings. In the drawings: Figure 1 is a block schematic diagram of a first embodiment of the apparatus in accordance with the present invention; Figure 2 is a circuit diagram showing in detail part of the apparatus of Fig. 1; Figure 3 is a circuit diagram showing another part of the apparatus of Fig. 1; Figure 4 is a block schematic diagram illustrating a second embodiment of the present invention; Figure 5 is a circuit diagram showing part of the apparatus of Fig. 4; Figure 6 is a circuit diagram showing another part of the apparatus of Fig. 4, and Figure 7 is a circuit diagram showing a further part of the apparatus of Fig. 4.

Referring to Fig. 1 of the drawings apparatus for automatically controlling the supply of electrical energy to lighting apparatus includes an ultrasonic transmitter 10 and an associated ultrasonic reciever 11. The ultrasonic transmitter has a piezoelectric type transducer and is arranged to emit ultrasonic waves. The frequency of the ultrasonic waves can be adjusted for maximum sensitivity according to the particular transducer used. The receiver 11 also includes a piezoelectric type transducer and is arranged to receive and amplify the transmitted signal. The receiver is arranged to detect modulation of the transmitted signal due to motion of an object or person within a given range of the receiver.

The receiver gives a logic output which is high or low depending upon the level of modulation. The output is high when there is no modulation and low when the modulation reaches a certain level.

The output of the receiver 11 is connected to a gating circuit 1 2 which has an output connected to a solid state relay 14. The relay 1 4 effectively has a contact 1 5 which is connected in the electrical power supply line of lighting apparatus 1 6.

The apparatus also includes a light sensor 1 8 which is arranged to sense the light level in the vicinity of the apparatus and to provide a logic output which is high or low depending upon whether the light level is above or below a predetermined value. The output appears on line 1 9 which is connected to the gating circuit 1 2. The predetermined light level is adjustable.

Electrical power for the units making up the apparatus by a d.c. power supply 20.

In operation if there is no movement of an object or human being within a predetermined range of the receiver 11 the output from the receiver 11 remains high and the gating circuit 1 2 does not supply a signal to energise the relay 1 4. Thus the circuit remains open and the lighting apparatus is not energised.

If the movement of a human being or object occurs within the range of sensitivity of the receiver 11 this movement will cause modulation of the frequency of the received signal. This modulation is detected by the receiver circuit which responds by changing its output level from high to low. If the light sensor 1 8 senses that the level of light has fallen below a pre-set level, the level of its output signal on line 1 9 changes to a low state. The gating circuit then responds to these two inputs by energising the relay 1 4 to cause illumination of the lighting apparatus 16.

If the light sensor 1 8 does not sense a light level below the pre-set level the output from the gating circuit remains unchanged. The relay 14 is not energised. The lighting appa ratus is not illuminated. The gating circuit 1 2 is designed not to respond to a signal from the lighting sensor 1 8 when the lighting apparatus has been energised.

Thus it will be seen that the present apparatus provides a means of automatically switching on a lighting apparatus in response to movement within a predetermined range of the sensing apparatus. In the case of the ultrasonic sensor the range is of the order of 5 metres.

A circuit diagram of the ultrasonic transmitter 10 is given in Fig. 2. Briefly this comprises stabilised dc supply 24 which is fed via a transformer 25 and a diode rectifier 26. The output of an integrated circuit oscillator 29 is fed to an ultrasonic transmitter 38.

A circuit diagram of the ultrasonic receiver 11 is given in Fig. 3. Briefly this comprises an ultrasonic receiving element 30 which has an associated transducer for producing an electrical signal indicative of the ultrasonic signal received. This electrical signal is amplified by an amplifying stage 31.

Only when a modulated signal is received and amplified by the amplifying stage 31 is the modulating frequency detected and the resulting signal fed to the input of the intgerated circuit 32.

The output of the stage 32 is fed to an integrated circuit 33 which forms the gating circuit 1 2 of Fig. 1. The light sensor includes a photosensitive element 35 which is connected to one input of a comparator 36. The other input of the comparator, which is a reference input, is derived from a voltage divider comprising resistors 38 and 39 and a variable resistor 40. The output of the comparator 36 is high or low depending upon the signal recived from the photosensitive element 35 and this output is fed to the gating circuit 33. The light level at which the comparator output changes state can be adjusted by adjusting variable resistor 40. The output of the gating circuit which controls energisation of the relay 14 appears on line 42.

A second embodiment of the invention is shown in Fig. 4 of the drawings. This is a similar arrangement to that shown in Fig. 1, the main difference being that it has a microwave sensing unit instead of the ultrasonic sensor. The microwave sensing unit which is a microwave Doppler module is shown at 50 in Fig. 4. The remaining blocks namely the light sensor gating circuit and solid state relay are similar to those of Fig. 1 and are shown by like reference numerals. The microwave Doppler module 50 is arranged to radiate microwave energy and to receive any reflective microwave energy. As long as reflection is from a static object the received signal has the same frequency as the radiated signal. If the received signal comes from a moving object a Doppler shift occurs in the frequency. This is sensed by the Doppler module which then changes the level of its output signal from high to low.When the output of the Doppler module 50 changes from high to low the gating circuit 12 produces a signal to energise the relay 14 and provided the output of the light sensor 1 8 is low, this results in electrical energy being supplied to the lighting apparatus.

The light sensor 1 8 operates in the manner already described with reference to Fig. 1.

The microwave module has a range of oper-ation of the order of 25 metres.

Detailed circuit diagrams of the microwave transmitter and receiving equipment are given in Figs. 5, 6 and 7. Briefly this has a stabilised dc supply 53 (Fig. 5) which is fed via transformer 51 and a diode rectifier 52. Referring to Fig. 6 a Gunn device 54 radiates microwave power and a mixer diode 55 receives local microwave power from the Gunn device and also reflected microwaves from objects within its range of sensitivity.

If all objects within the range of the device are stationary both signals received by the mixer diode 55 are of the same frequency and the output from the diode is dc. A moving object or human being within the range of the device produces a doppler shift in the reflected signal which in turn produces an ac signal at the input to the amplifier 56. The amplified signal is rectified and utilised to switch on a transistor 57 (Fig. 7) giving a low input to an integrated circuit gate 59. If the light sensor 58 senses that the level of light has fallen below a pre-set level the sensor output signal on line 60 changes to low output. The gating circuit then responds to these two low inputs by energising the relay to cause illumination of the light apparatus 1 6.If the light sensor 58 does not sense a light level below the pre-set level the output from the gating circuit remains unchanged.

The relay is not energised. The lighting apparatus is not illuminated. The gating circuit 59 is designed not to respond to a signal from the lighting sensor 58 when the lighting apparatus has been energised.

Thus it will be seen that the present microwave apparatus provides a means of automatically switching on a lighting apparatus in response to movement within a predetermined range of the sensing apparatus. In the case the microwave sensor the range is of the order of 25 metres.

In the circuits of Figs. 3 and 7 the gating circuits 33 and 59 are C-MOS 4001 B Quad 2-input NAND gates.

The above are two embodiments of the present invention. It wil be appreciated that there are other ways in which the present invention can be implemented and for example it is possible to use an infra-red type sensing unit to automatically control switching on of a lighting apparatus.

The present arrangement has several possi ble applications. It can be used to control switching of lights without any requrement for manual operation of a switch. The unit can be used to conserve energy by ensuring that lighting is energised only when for example human beings are present in the vicinity of the unit. The apparatus can be used as an intruder deterrent by energising external lighting on the approach of a pedestrian or a vehicle. Similarly it can be used to reduce vandalism by using it in the place of normal switch apparatus in unsupervised areas such as public sub-ways, stairways etc. The apparatus could also be used to provide lighting of roads, streets or drive ways upon approach of vehicles or pedestrians.

CLAIMS (FILED ON 27/6/80) 1. Apparatus for controlling the application of electrical energy to a light comprising motion sensing means for sensing movement of an object within a given range thereof, and switching means which is arranged to be actuated in response to said sensing means sensing said movement, said switching means being for connection in circuit with a light whereby when said switching means is actuated electrical energy is supplied to said light.

2. Apparatus as claimed in claim 1 wherein the sensing means comprises an ultrasonic sensing means.

3. Apparatus as claimed in claim 2 wherein the ultrasonic sensing means comprises an ultrasonic transmitter and an ultrasonic receiver, said ultrasonic receiver being arranged to detect amplitude modulation of the received signal and to produce an output signal the level of which is high or low depending upon the detected modulation.

4. Apparatus as claimed in claim 1 wherein the sensing means comprises a microwave sensing means.

5. Apparatus as claimed in claim 4 wherein the microwave sensing means includes a microwave Doppler unit which transmits microwave energy and detects any dop pler shift in the reflected signal, said unit being arranged to produce an output signal which is high or low depending upon whether the received signal includes a frequency shifted component.

6. Apparatus as claimed in any preceding claim wherein the switching means include a relay.

7. Apparatus as claimed in any preceding claim including light sensing means for sensing the ambient light intensity, the light sensing means being gated with said sensing means and being arranged to actuate the switching means when the ambient light has a predetermined intensity.

8. Apparatus for controlling the application of electrical energy to a light substantially as hereinbefore described with reference to and as shown in Figs. 1 to 3 or Figs. 4 to 7 of the accompanying drawings.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. ble applications. It can be used to control switching of lights without any requrement for manual operation of a switch. The unit can be used to conserve energy by ensuring that lighting is energised only when for example human beings are present in the vicinity of the unit. The apparatus can be used as an intruder deterrent by energising external lighting on the approach of a pedestrian or a vehicle. Similarly it can be used to reduce vandalism by using it in the place of normal switch apparatus in unsupervised areas such as public sub-ways, stairways etc. The apparatus could also be used to provide lighting of roads, streets or drive ways upon approach of vehicles or pedestrians. CLAIMS (FILED ON 27/6/80)

1. Apparatus for controlling the application of electrical energy to a light comprising motion sensing means for sensing movement of an object within a given range thereof, and switching means which is arranged to be actuated in response to said sensing means sensing said movement, said switching means being for connection in circuit with a light whereby when said switching means is actuated electrical energy is supplied to said light.