DE102005042568B3 - Radio linked motion detector has several double sided sensor circuit boards with complete ground plane and infrared sensor and amplifier on opposite sides - Google Patents

Abstract

A radio linked motion detector (13) has several double sided sensor circuit boards each with complete ground plane and infrared sensor (2) and amplifier (7) on opposite sides feeding a single processor (10) circuit board (8) and adjustable threshold daylight sensor (9) switching an autonomous power supply (12).

Description

The The invention relates to a radio motion detector with a equipped with an infrared detector Sensor circuit board. The invention can be used for wireless control a radio actuator can be used.

From the DE 38 03 277 A1 For example, there is known an infrared radiation receiver which is particularly suitable for motion detectors and which contains a current source and a transmitter which is controlled by the signals of the radiation receiver and in turn emits wireless control signals to a remotely located signal receiver. The device is independent of a supply network and can be used anywhere in a room to influence different circuits. The motion detector consists of a front receiving part and a rear transmitting part, wherein both parts are detachably connected to each other. The front receiver is an infrared radiation receiver with infrared detector and electronic evaluation device. The electronic evaluation device is realized on an electrical circuit board with a printed circuit, which carries in the middle of the infrared detector. It is also possible to provide a plurality of receiver elements with associated infrared detectors.

From the DE 101 50 128 C2 is a wireless sensor system is known, which has a solar cell with downstream energy storage and which by means of a Sen detelegramms information wirelessly -. B. via radio - to a mains-connected reception and evaluation - z. B. a lighting control - passes. The state of charge of the energy storage is monitored. As energy storage preferably serve a low-loss capacitor of high capacity or an electrochemical storage cell. There is a timer circuit which can be triggered as a function of a voltage level of the energy store and which activates the sensor system for transmitting at least one transmission telegram after a certain time interval in order to thus provide an improved status inquiry. The data transfer takes place at fixed or variable intervals even without movement of the monitored devices.

From the DE 103 56 071 A1 a wireless motion detector is known, which has a mode of operation for detection readiness and a power-saving mode for reducing the power consumption of the autonomous power source (battery, rechargeable battery). There is an automatic switching of the motion detector in each relevant operating mode in response to the ambient light.

From the DE 32 30 728 A1 an infrared sensor device for detecting motion processes with an infrared sensor is known, which receives the infrared radiation emitted by an object and emits a signal for an alarm transmitter during a relative movement of the object to the infrared sensor device. The power supply device for the infrared sensor and the alarm transmitter are a solar cell panel and an accumulator connected thereto.

From the US 4,644,164 a compact infrared sensor is known whose components are arranged on a printed circuit board, which has a central large-area metallization to form a reflector for the infrared light to be detected.

From the DE 296 22 840 U1 a device for receiving a sensor (optical motion detector) is known, wherein the device is divided into at least two areas. In a first room, a conventional sensor board (motion detector board) is housed. In a second room, an e / i converter board (with optocoupler, isolation transformer and relay) is cast in a potting compound. By a partition between the two spaces at least one electrical line is guided, which connects the motion detector board to the converter board. The motion detector can be installed within a hazardous area.

• • Je kleiner dieser Bias-Widerstand ist, desto größer ist der Stromverbrauch des Infrarotsensors.
• • Je größer dieser Bias-Widerstand ist, desto größer ist auch die Empfindlichkeit gegenüber elektromagnetischen Störungen (EMV).

An infrared sensor (PIR sensor) used in the wireless motion detectors consists of pyroelectric crystals and a FET amplifier (field effect transistor) as a preamplifier / impedance converter in the same housing. At the output of the FET amplifier, the output signal is present as an AC signal, superimposed by a DC offset. The AC component is on the order of a few mV, the offset in the range of a few volts. The so-called bias resistance of the FET amplifier allows the impedance of the output to be determined:

• • The smaller this bias resistance, the greater the power consumption of the infrared sensor.
• • The larger this bias resistance, the greater the sensitivity to electromagnetic interference (EMC).

Becomes z. B. a bias resistor of 47 kOhm used, this leads at a maximum offset of 1.55 volts already to a relative high static operating current of the infrared sensor of almost 33 μA.

Of the Invention is based on the object, a wireless motion detector with big ones EMC resistance - electromagnetic compatibility (i.e., resistant to electromagnetic interference) - indicate which at the same time has an optimally low power consumption.

• – mit mindestens einer doppelseitig bedruckten Sensor-Leiterplatte,
• • bestückt mit einem Infrarotsensor auf ihrer ersten, als vollflächiger Ground-Layer ausgeführten Seite,
• • bestückt mit einem Verstärker inklusive Filter und Schwellwertschalter auf ihrer zweiten Seite,
• – mit einer von der Sensor-Leiterplatte getrennten Auswertungs-Leiterplatte, bestückt
• • mit einem Tageslichtsensor mit einstellbarem Dämmerungsschalter,
• • mit einer das Ausgangssignal des Verstärkers erhaltenden Auswerteeinheit mit einstellbarem Zeitglied,
• • mit einer Temperaturerfassungs-Messeinrichtung, deren Ausgangssignal dem Verstärker zugeleitet wird,
• • mit einem das Ausgangssignal der Auswerteeinheit empfangenden Funksender und
• • mit einer autarken Energieversorgung, welche vom Ausgangssignal des Tageslichtsensors eingeschaltet/ausgeschaltet wird und nach Aktivierung alle stromverbrauchenden Komponenten der Sensor-Leiterplatte und der Auswertungs-Leiterplatte speist.

This object is achieved by a wireless motion detector

• With at least one double-sided printed sensor circuit board,
• • equipped with an infrared sensor on its first side, designed as a full-surface ground layer,
• • equipped with an amplifier including filter and threshold switch on its second side,
• - Equipped with a separate from the sensor circuit board evaluation board
• • with a daylight sensor with adjustable twilight switch,
• With an evaluation unit with adjustable timing element which receives the output signal of the amplifier,
• With a temperature measuring device whose output signal is fed to the amplifier,
• • with a radio transmitter receiving the output signal of the evaluation unit and
• • with a self-sufficient power supply, which is switched on / off by the output signal of the daylight sensor and, after activation, powers all current-consuming components of the sensor PCB and the evaluation PCB.

The particular advantages of the invention are that it is possible with the proposed wireless motion detector, a relatively large one Bias resistance to use, d. H. the values can be greater than one megohm. Of the resulting operating current of the infrared sensor is thereby reduced to a value of 1.6 μA. Accordingly results from the extremely "gentle" operation of the autonomous energy supply a long life respectively a large power reserve (Period in which the wireless motion detector without newly supplied energy is operable). At the same time, of course, the required high Given EMC resistance.

Further Advantages will be apparent from the following description.

advantageous Embodiments of the invention are characterized in the subclaims.

The Invention will be described below with reference to the drawing Embodiments explained. It demonstrate:

1 a first embodiment of a radio motion detector,

2 a second embodiment of a radio motion detector.

In 1 a first embodiment of an energy self-sufficient wireless motion detector is shown. It is a system with a wireless motion detector 13 and a wirelessly controlled radio actuator 14 to detect, with wireless communication between a radio transmitter 11 the wireless motion detector 13 and a radio receiver 15 of the radio actuator 14 he follows. The wireless motion detector 13 has at least two separate printed circuit boards, namely a sensor circuit board 1 (Sensor Board) and an evaluation board 8th (Controller board).

• • Das Filter des Verstärkers 7 befreit das elektrische Signal des Infrarotsensors 2 von sehr schnellen und sehr langsamen Anteilen. Somit wird verhindert, dass sehr schnelle Signale, z. B. von vorbeifahrenden Autos oder extrem langsame Signale, die z. B. durch den Einfluss von Sonne und Wolken hervorgerufen werden, Schaltvorgänge auslösen.
• • Der Schwellwertschalter des Verstärkers 7 überprüft das gefilterte elektrische Signal auf seine Höhe. Die Schwelle ist so eingestellt, dass nur Signale, die von einem Menschen im Erfassungsbereich herrühren, durchgeschaltet werden. Schwächere Signale, die beispielsweise von Haustieren oder sonnenerwärmten, windbewegten Blättern verursacht werden, erreichen die vorgegebene Schwellenspannung nicht und werden verworfen.

The sensor circuit board 1 has an infrared sensor 2 (Passive infrared detector PIR), which contains two pyroelectric crystals 3 . 4 includes (dual sensor), which are connected together with opposite polarity. The crystals 3 . 4 Due to the thermal radiation of a moving thermal object, they emit a characteristic electrical signal that is transmitted by a field effect transistor 5 comprising drain D, gate G and source S before being amplified. The crystals 3 . 4 are connected between ground GND and gate G, the series connection of the crystals being a bias resistor 6 is connected in parallel. The output signal of the infrared sensor 2 gets to an amplifier 7 including filter and threshold switch:

• • The filter of the amplifier 7 frees the electrical signal of the infrared sensor 2 of very fast and very slow proportions. This prevents very fast signals, eg. B. from passing cars or extremely slow signals z. B. caused by the influence of sun and clouds, trigger switching operations.
• • The threshold switch of the amplifier 7 checks the filtered electrical signal for its height. The threshold is set so that only signals originating from a person in the detection area are switched through. Weaker signals, caused for example by domestic animals or sun-warmed, wind-swept leaves, do not reach the predetermined threshold voltage and are discarded.

The connections between the building components are as short as possible to the surfaces on the sources of interference can act to minimize. The sensor circuit board 1 is designed such that the largest possible area can be used for the shield. This is the double-sided printed sensor board 1 on its first, as full-surface ground layer (GND layer) running side with the infrared sensor 2 and on her second page with the amp 7 stocked. It is also important that only the components for a channel (only a single infrared sensor) are combined on a sensor PCB. To adapt the beam path and optical components can be arranged on the sensor circuit board.

That from the amplifier 7 formed output is one on the evaluation board 8th located evaluation unit 10 supplied, which has an adjustable timer, which by the signals of the amplifier 7 is triggered, so as to turn on the lighting fixture to be controlled directly, but only after a (by means of the timer) predetermined duration after the appearance of the last signal of the amplifier 7 off. On the output side, the evaluation unit acts on 10 the aforementioned radio transmitter 11 ,

A daylight sensor 9 including adjustable twilight switch evaluates the current intensity of daylight and activates the wireless motion detector 13 only if a preset brightness level (twilight switch) is undershot. Then the daylight sensor switches 9 including twilight switch an energy supply 12 the wireless motion detector 13 one, leaving the power-consuming components 2 . 7 . 10 . 11 be fed with supply energy. The energy supply 12 is network independent, it is z. For example, a long-life battery, an accumulator, a solar panel (solar cells with memory) or a SuperCap. If the preset brightness level is exceeded, the power supply is switched off 12 from the power consuming components 2 . 7 . 10 . 11 , The daylight sensor 9 is of course permanent with the power supply 12 connected.

The range of a motion sensor with infrared sensor is generally dependent on the currently prevailing ambient temperature. The amplifier 7 therefore includes an automatic range stabilization, which controls the electronic gain of the microprocessor used as a function of the ambient temperature. The temperature sensing measuring equipment required for reliable operation of the motion detector with minimized range and range detection 21 is located on the evaluation circuit board 8th , The output signal of the temperature detection measuring device 21 becomes the amplifier 7 fed.

Except for the above-mentioned turn-on / turn-off depending on the brightness level (ie, turning off the wireless motion detector during the daytime in which a motion detector driving a lighting fixture is turned off due to high light intensity), the infrared sensor becomes 2 and the amplifier 7 (as well as evaluation unit 10 and radio transmitters 11 ) are used in continuous operation, whereby very long settling times are avoided due to long filter time constants.

If the motion detector detects a movement of a person within its detection range, it radiates over the radio transmitter 11 a command signal (radio signal) from which the radio receiver 15 of the radio actuator 14 reached and there a Auswer teeinheit 16 acted on which output a switching element 17 controls so as to one with the switching element 17 Turn on or off connected lighting fixture. The switching element 17 connects the lighting fixture to a power supply (mains) 18 or separates the lighting fixture from the power supply 18 ,

In 2 a second embodiment of a wireless motion detector is shown. In this embodiment, the wireless motion detector 13 several, here by way of example three separate sensor circuit boards 1 . 19 . 20 on which in the above for sensor board 1 are formed, each having its own infrared sensor and each having a channel of the wireless motion detector 13 form. With the help of the sensor circuit boards 1 and 19 is z. B. a radio motion detector with a detection range of more than 180 ° formed while passing through the sensor circuit board 20 In addition, a creep protection is realized. All sensor boards 1 . 19 . 20 is the only evaluation board 8th assigned.

The output signals of the amplifiers (see amplifier 7 ) of the sensor circuit boards 1 . 19 . 20 apply the evaluation unit 10 the evaluation board 8th , The energy supply 12 feeds the components of all sensor boards 1 . 19 . 20 , The remaining structure of the evaluation circuit board 8th is like under 1 explained. Of course, the evaluation board has 8th again the temperature detection measuring device 21 on which their output signals the amplifiers 7 the individual sensor boards 1 . 19 . 20 supplies. The radio transmitter (not shown) of the evaluation board 8th gives radio signals to the radio receiver 15 of the radio actuator 14 off, like under 1 explained is executed.

Of course, and as is well known, the wireless motion detector 13 a (not shown) manual setting devices for setting the twilight setting or brightness threshold (in which the device is to start with the detection of infrared radiation within a defined detection range) and to specify the off delay or lag time of the controlled lighting fixture on.

In the above embodiments, unidirectional communication is performed by the wireless motion detector 13 to the radio actuator 14 used. Of course, the invention also in bidirectional communication (radio transmission in both directions) can be used.

In the above embodiments is always a system with a single wireless motion detector 13 and a single radio actuator 14 explained. The invention is of course also applicable to systems with multiple wireless motion detectors that control a wireless actuator, as well as for systems with a wireless motion detector, which controls several wireless actuators.

1

Sensor circuit board

2

infrared sensor (Passive infrared detector PIR)

3

pyroelectric crystal

4

pyroelectric crystal

5

Field Effect Transistor

6

Bias resistor

7

Amplifier included Filter and threshold switch

8th

Evaluation board

9

Daylight sensor with adjustable twilight switch

10

evaluation with adjustable timer

11

radio transmitter

12

power supply

13

Wireless Motion

14

Radio actuator

15

radio receiver

16

evaluation

17

switching element (for turning ON / OFF a lighting fixture)

18

power supply (Network)

19

Sensor circuit board

20

Sensor circuit board

21

Temperature sensing measuring device

D

drain

S

source

G

gate

GND

Ground (Earth)

Claims (2)

Wireless motion detector ( 13 ) - with at least one double-sided printed sensor PCB ( 1 ), • equipped with an infrared sensor ( 2 ) on its first side running as a full-surface ground layer, • equipped with an amplifier ( 7 ) including filter and threshold switch on its second side, - with one of the sensor PCB ( 1 ) separate evaluation board ( 8th ), equipped • with a daylight sensor ( 9 ) with adjustable twilight switch, • with one the output signal of the amplifier ( 7 ) receiving evaluation unit ( 10 ) with adjustable timer, • with a temperature measuring device ( 21 ) whose output signal is the amplifier ( 7 ), with one the output signal of the evaluation unit ( 10 ) receiving radio transmitter ( 11 ) and • with a self-sufficient energy supply ( 12 ), which depends on the output signal of the daylight sensor ( 9 ) is turned on / off and after activation all power consuming components ( 2 . 7 . 9 . 10 . 11 ) of the sensor circuit board ( 1 ) and the evaluation board ( 8th ) feeds. Wireless motion detector ( 13 ) according to claim 1, characterized in that at least two separate sensor circuit boards ( 1 . 19 . 20 ) - each equipped with an infrared sensor ( 2 ) and an amplifier ( 7 ) - and a single evaluation board ( 8th ), whose evaluation unit ( 10 ) the output signals of the amplifiers ( 7 ) receives.