DE202004020712U1 - Measurement sensor for measurement arrangement, e.g. Hall sensor mounted near railway vehicle wheel, has at least one sensor component and stimulation coil with connections for common supply voltage - Google Patents

Abstract

The measurement device has at least one electromagnetic sensor component (IC101) for generating a measurement signal and a stimulation coil (9) near the sensor component for generating an electromagnetic stimulation field for the sensor component. At least one sensor component and at least one stimulation coil have connections for a common supply voltage.. An independent claim is also included for the following: (A) a measurement arrangement with at least one measurement sensor.

Description

The The invention relates to a sensor. In measuring devices, for example, sensors are used in rail vehicles designed as a Hall sensor, which is mounted in the region of a gear are. The Hall sensor is so in the teeth of the gear attached that through the teeth caused flux change a magnetic field is detected by the Hall sensor.

It is desirable to obtain additional information about the proper functioning of the sensor during operation. The EP 0 886 762 B1 shows a method and a device for checking a sensor component.

In the arrangement of the DE 44 36 875 A1 a bending area is provided in the circuit board in order to be able to place the circuit board around an edge of the magnet housing. The flexible film shown there connects a printed circuit board with a Hall probe, which is held on a support body. The film is an electrical connection in which the individual conductors are combined to form a film.

It It is an object of the invention to provide an improved sensor.

Of the inventive sensor has a Printed circuit board with a first and a second rigid Leiterplattenbe rich on. In between, there is a flexible circuit board area, wherein on the flexible printed circuit board area at least one sensor component is arranged. The first and second rigid circuit board area are arranged next to each other. With such a sensor can be a particularly accurate angular arrangement of a sensor component with respect to reach both rigid circuit board areas. By the length of the flexible PCB area and by the arrangement of the sensor component on the flexible circuit board area can namely namely with its angle with respect to the Predict rigid PCB areas very accurately. If the rigid circuit board areas lie together, then forms the intermediate flexible printed circuit board area namely one Bow with very precisely predeterminable bending line. By the Position of the sensor component on this bending line results in the angular twisting of the sensor component with respect to the flexible printed circuit board areas.

to Improvement of the connection between the first and second printed circuit board area are fasteners provided which slipping the prevent rigid PCB areas from each other.

The Sensor housing points advantageously guide rails for the first and the second rigid circuit board area in which this guided become. That way a particularly accurate angular arrangement of the sensor component in terms of reach the sensor housing.

With the training of the invention with adjacent rigid PCB areas can be in a particularly simple way contacting with a connector or reach a connection socket. This will be in the area of a Kontaktrandes the circuit board exposed traces on the provided on the first or on the second rigid circuit board area. On these exposed tracks then an electric Connection socket are plugged, the socket at least having a spring contact area. This spring contact area occurs on the one hand with one of the two rigid PCB areas and on the other with a trace on the other rigid circuit board area in contact. It is also possible, to provide two contact springs in the spring contact area, of which one each a trace on one of the two rigid circuit board areas contacted.

The spring contact region has in each case two opposite clamp contacts, which are designed to be spring-displaceable against an inserted therebetween printed circuit board. In this way, a particularly good and lasting contact can be achieved. These aspects of the invention are good in 6 to 9 to see.

1 shows a schematic circuit diagram of a part of a first sensor according to the invention,

2 shows a schematic diagram of a Hall sensor IC101, as a sensor element in the sensor according to 1 is used,

3 shows a typical course of a supply voltage, which is a test signal for the probe 1 having,

4 shows a part of the course of the supply voltage 3 in an enlarged view,

5 shows a response from the probe 1 to a supply voltage according to 3 .

6 shows a cross section through a printed circuit board on which the sensor after 1 is constructed,

7 shows a plan view of a switch card for the printed circuit board after 6 .

8th shows a cross section through a first part of a sensor according to the invention,

9 shows a cross section through another part of a probe after 8th .

10 shows a schematic circuit diagram of a part of a second sensor according to the invention,

11 shows a schematic circuit diagram of a part of a third sensor according to the invention,

12 shows a waveform for components of the probe 11 .

13 shows a block diagram, the sensor after 1 illustrated, and

14 shows a block diagram, the sensors after 10 and 11 and another sensor.

at All the following circuit descriptions are for the understanding of Function of the circuit concerned unnecessary components omitted. Which includes For example, passive components that overload the other components counteract such as current limiting resistors, EMC components, Filter capacitors, reverse polarity protection diodes and the like

1 shows a schematic diagram of a first sensor according to the invention 1 which is arranged as a pulse generator in connection with a gear, not shown here, on an axle of a rail vehicle.

The sensor 1 has a supply voltage terminal X101 for application of a voltage V _S , a ground terminal X102, and a signal output terminal X103. The ground terminal X102 extends as the center ground GND1 through the entire circuit of the probe 1 ,

In an embodiment not shown here only two interface connections are provided. Then that will be Output signal formed as a function of the total current consumption.

In this view is not shown that the probe 1 two identical circuits according to 1 having. This is done for redundancy, for comparison and for a not illustrated here generation of a corresponding corrected total result signal from two individual output signals.

The central part of the circuit is powered by a sensor 2 educated. As a sensor element is a Hall sensor IC101, the circuit in 2 is shown schematically. This block provides a digital output signal ("open collector"). The magnetic flux density difference between the two Hall elements integrated on the module is evaluated. If a difference of more than 2.5 mT is exceeded, an output transistor switches the output of the Hall sensor IC101.

In order to detect the teeth of a non-magnetic gear, which generates substantially no magnetic field, a permanent magnet, not shown here, is glued to the back of the Hall sensor IC101. The permanent magnet is so large that it covers all the two Hall sensors IC101 (eg double encoder), namely the IC101 and another IC, not shown here, of another circuit. This is done because with two individual magnets mutual interference could occur (repulsion or distortion of the magnetic field). The gear is in the range of Hall probes 3 of the sensor element IC101 arranged that its teeth to the Hall probes 3 pass by without touching them. The teeth of the gear cause a magnetic field change. This is detected by the Hall sensor IC101 and accordingly switches its output "Pin 2".

through of the capacitor C108 becomes the lower limit frequency of the sensor element established. It should be recognized pulses up to 1Hz. So it was the cutoff frequency is set to 1 Hz.

With a low-pass circuit, not shown here from one at the port Vs arranged resistor and a between the terminals "1" and "3" or "4" arranged condenser is possibly a EMC protection for provided the sensor element IC101.

The power source 4 is formed by an npn transistor T105, by two resistors R119 and R121 and by a reference zener diode D107, which, as in FIG 1 shown connected between the supply voltage V _S and the pin "pin 2" of the Hall sensor IC101 are connected. When the output transistor (open collector) of the Hall sensor IC101 turns "low", a current flows through the reference Zener diode D107, the resistor R121 and the base of the transistor T105, and the voltage of the reference Z is applied to the resistor R119 This results in a predetermined current flow at the emitter of the transistor T105 It is also conceivable to provide this current through a plurality of transistors if the heat load for the transistor T105 is too great. Pnp transistor, not shown here, the base of which is connected to the collector of the transistor T105 and whose collector is connected to the base of the transistor T105. The emitter of this transistor is connected to the terminal "2" of the Hall sensor IC101.

The current through the power source 4 and the supply current of the Hall sensor IC101 - the intrinsic demand of the module - give the "high" value of the pulse generator current signal, which is applied as one of the two provided output signals at the signal output terminal X103. If the output transistor of the IC101 IC is disabled, current will not flow through the power source. Only the supply current of the IC101 sensor IC flows. This represents the "low" value of the pulser current signal having a predetermined value applied to the signal output terminal X103 as the other of the two output signals provided.

Assuming the above components, professional implementation and provision of additional conventional passive components, the sensor is 1 operational. When excited by the rotating at a certain frequency gear a rectangular current is generated, the frequency of which results from the product of the rotational frequency and the number of teeth of the gear.

To detect a defect in the area of a sensor tip, in which the sensor 2 is arranged, the supply voltage Vs by a destruction detector 5 off. To detect a defect is a Sens trace 6 provided in the region of the sensor whose state is controlled by a flip-flop 7 is sampled, which operates a FET T108.

After switching on the sensor by applying the supply voltage Vs is an npn transistor T110 of the flip-flop 7 blocked. When T110 turns off, the npn transistor T111 becomes conductive through a resistor R137 and via a base resistor, not shown. This causes the transistor T110 remains disabled. Due to the blocking of T110, the pnp transistor T109 also turns off, so that a current flows through the Zener diode D114 via the resistor R125, and a predetermined DC voltage is produced at the field effect transistor T108. This is sufficient to switch through the FET T108 and downstream function blocks of the sensor 1 to provide energy.

If it now happens that the sensor is damaged by "milling off" the rotating rotor or gearwheel, the sensor trace becomes damaged 6 interrupted on a carrier board, not shown here. As a result, a capacitor, not shown here, charges via resistors and the NPN transistor T112 becomes conductive. The npn transistor T111 is turned off and the npn transistor T110 is turned on via the resistor R110 and via another resistor, not shown here. When transistor T110 conducts, transistor T111 turns off. The locking of T111 then takes place regardless of whether the trace remains interrupted on the carrier board, or whether, for example by the conductive pole (gear) again a conductive connection is formed (stored state). Namely, it is between the base of the transistor T112 and the terminal "3" of the Sens track 6 a capacitor, not shown here, provided by the Wiederleitendwerden the sense-track 6 unloaded. This discharge is delayed by means of a suitable, not shown resistor.

The transistor T110 remains conductive. Therefore, the PNP transistor T109 also becomes conductive via a resistor, not shown, and short-circuits the Zener diode D114, thereby disabling the FET T108. The following circuit blocks, in particular the current source 4 , are thus tensionless. As a result, it is not possible for the probe 1 Outputs pulses that arise due to a defect and may lead to misinterpretations in the higher-level evaluation unit to which the sensor 1 connected.

Already a momentary interruption of the Sens trace 6 is sufficient to the sensor 1 permanently disable. The stored switch-off state is canceled when the supply voltage is switched off / on again. If, after the supply voltage has been switched on, the state of a disconnected sense printed circuit is still present, the supply voltage for the subsequent circuit blocks is switched off again, as described above.

The sensor 1 still has a sensor test circuit 8th on, with which the sensor 2 can be selectively stimulated. This is achieved by a flux density changing magnetic field from a stimulus coil 9 is produced. This magnetic field simulates a rotating flywheel (gearwheel) that normally provides magnetic field change during travel of, for example, a train, as described above.

By means of this magnetic field stimulation, the sensor can be 2 test for its function. In the event that the sensor 2 is used on a rail vehicle, the test function is triggered after the standstill of the rail vehicle and takes about 5 seconds. To distinguish itself from a periodic signal (frequency signal while driving), a stimulus is used in the form of a special code which is modulated onto the supply voltage Vs.

in the Test operation will be the supply voltage of 15V (normal operation) temporarily switched up to 21V. The sensor test scarf recognizes this and leads independently the activation of the coil, resulting in a magnetic field change leads.

The reference Zener diode D111 generates a reference voltage Vref independent of the supply voltage Vs. This reference voltage Vref defines the switching point for OP IC102 - type rail-to-rail. The OP IC 102 compares this voltage at the "+" input "5" with the voltage at the "-" input "6" resulting from the voltage divider R117 / R118 and dependent on the supply voltage Vs. It is used here as a "comparator", which can switch both to 0V (low) as well as to U _b (high).

ever according to total tolerance (tolerance, temperature, service life) of the used Components lies - related to the supply voltage - the Switching threshold at approx. 18V. This means that at the supply voltage in normal operation of 15.2V the output of the OP IC102 due to its rail-to-rail characteristics approximate takes the value of the supply voltage. If the test case is i.e. that the supply voltage is switched up to 21.2V, the output "7" of the OP IC102 switches to 0V.

In test mode (21.2V), the OP output "7" of IC102 is temporarily at 0V. Via a resistor, not shown here, the pnp transistor T104 is driven and it switches on the supply voltage Vs. As a result, a voltage is applied to the base of the npn transistor T101 - Zener diode D105. At the same time, the npn transistor T102 (T202) is conductively controlled via a resistor, not shown here, and it applies the GND potential to the stimulus coil 9 , Through the stimulus coil 9 thus flows a predetermined current.

Of the Coil current causes a flux density change between the two Hall elements of the sensor IC 101 of ≥ 2.5mT.

To damage the stimulus coil 9 Preventing coil current from being applied too long if the supply voltage is inadvertently held at a test level for too long is a safety shutdown 10 intended. A predetermined voltage is applied to the "+" input "5" of the comparator IC103, which is generated by means of a reference Zener diode D113.The capacitor C112 is charged via a resistor R124 "of the comparator IC103 exceeded the predetermined voltage, the comparator IC103 (open collector) switches its output to 0V and it short-circuits the Z-diode D105. This will further control the stimulus coil 9 prevented.

In normal operation, where Vs is about 15.2V, the OP output is "7" from IC102 to U _b . Thus, via a resistor, not shown, the npn transistor T103 becomes conductive. This causes the capacitor C112 necessary for the turn-off of the coil drive to be discharged. The pnp transistor T104 blocks. The stimulus coil 9 does not receive power.

The current flow of the stimulus coil is prevented in normal operation. The GND connection of the coil is canceled with the npn transistor T102. This blocks because the pnp transistor T104 blocks. Due to the blocking of the transistor T104, the npn transistor T101 also turns off. In addition, a diode in front of the stimulus coil also an unwanted current flow through the stimulus coil 9 prevent in normal operation.

3 shows a typical course of a supply voltage, which is a test signal for the probe 1 having. 4 shows part of the supply voltage 3 in an enlarged view. The test signal was in 3 divided into five areas "1" to "5", each representing a duration of 1s.

The test signal has two functions. First, the sensor 2 a changing magnetic field predetermined (test cycles 1 to 3). This makes it possible to check the sensor element and the downstream signal adaptation (not shown here). This test lasts about 3s. The test cycles 4 and 5 (21V continuous signal) are used for the safety shutdown 10 to test. This is important because it prevents overloading of the coil. The test cycles 4 and 5 together take about 2 s. After about 500ms, the safety shutdown must 10 the stimulus coil 9 to become active. Since the test signal according to 3 and 4 and the expected response of the sensor 9 according to 5 are known, can be in the parent evaluation a comparison of the two signals perform and rate accordingly.

6 . 7 . 8th and 9 illustrate the mechanical structure of the probe according to the invention 1 ,

6 shows a circuit board 12 , on the two circuits according to 1 are housed.

The board 12 is divided into a first rigid circuit board area 13 into a second rigid circuit board area 14 as well as in a flexible PCB area 15 that is between the first rigid PCB area 13 and the second rigid circuit board area 14 is trained. The board 12 has a continuous polyimide foil 16 on, which is easily bendable.

The polyimide film 16 is on its top and on its underside with tracks 17 made of copper. The bottom has the board 12 in the in 6 left-side half a first stiff fiber optic card area 18 and on the right side a second fiber optic card area 19 , The first fiber optic card area 18 is at the bottom with two center knobs 20 provided in the centering openings 21 in the second fiber optic card area 19 are pluggable. The flexible PCB area forms for this purpose 15 a kind of hinge around which the first rigid circuit board area 13 and the second rigid circuit board area 14 can be swiveled.

On the top of the board 12 is in the flexible PCB area 15 a sensor stimulator 22 placed. The sensor stimulator 22 forms part of the sensor test circuit 8th out 1 , On the bottom of the board 12 are in the flexible PCB area 15 the two sensor elements IC101 of the two circuits according to 1 intended.

In addition, other components of the circuits according to 1 provided, both on the flexible circuit board area 15 as well as on the first rigid PCB area 13 and the second rigid circuit board area 14 , The top of the board 12 is with a Lötstoplackschicht 23 Mistake. On the bottom of the board 12 is in the flexible PCB area 15 a cover sheet 24 appropriate. On the top of the board 12 are edges on the reeds 25 from the Lötstoplackschicht 23 released.

7 shows a plan view of the sensor stimulator 22 out 1 , The sensor stimulator 22 is built on a PCB insulation material, on which the two Sens-tracks 6 out 1 made of copper are laminated on. The sensor stimulator 22 has two recesses for the two coils 9 on, which are fitted in these wells. The spools 9 are via contacts, not shown in this view, on the underside of the sensor stimulator 22 connected. There they will be on the board 12 soldered. Likewise, the two Sens interconnects 6 at the ends connected with vias, where they connect to the board 12 get connected.

8th shows a portion of the mounted sensor 1 in enlarged cut representation. The sensor 1 has an outer tube 26 made of sheet steel or cast aluminum with an end cap arranged in it 27 made of plastic, brass or aluminum. The graduation cap 27 is with an O-ring 28 opposite the outer tube 26 sealed. Inside the end cap 27 is a retaining cap 29 for the board 12 intended. Here, the holding cap is divided 29 in two cap shells 30 , which complement each other in a complementary way.

It is in the cap shells 30 a flex foil channel 31 released the flexible circuit board area 15 the board 12 receives. locking lugs 31 the retaining cap 29 engage in detent openings 32 in the graduation cap 27 one.

As you can see in this view especially well, is in the retaining cap 29 a permanent magnet 33 held. Edge protection lands 34 as part of the cap shells 30 are formed, prevent the fact that the flex foil of the conductor 17 on the permanent magnet 33 scrubs.

It remains to mention that on the inside of the outer tube 26 guide rails 35 are provided, in which the first fiber optic card area 18 and the second fiber optic card area 19 are guided.

At the top of the outer tube 26 are still flanged edges 36 trained, which are flanged in a forming step, not illustrated here, so that the end cap 27 firmly in the outer tube 26 is anchored.

Passageways 37 allow a passage of, for example, liquid adhesive between the area of the permanent magnet 33 and the inside of the outer tube 26 below the retaining cap 29 ,

9 shows a section of the probe 1 who is facing the in 8th shown area at the other end of the outer tube 26 is located. As you can see in this view, one is with a cable 38 connected connection cap 39 in the other end of the outer tube 26 plugged in. The connection cap 39 is made of plastic and with an O-ring 40 opposite the outer tube 26 sealed. Bördelbereiche 41 of the outer tube 26 are crimped in a manufacturing step, not shown here and hold the connection cap 39 firmly in the outer tube 26 , The cable 38 flows into contact springs 42 of which two each form a clamp contact. The contact springs 42 each with a contact tongue 25 in contact. To achieve the spring and clamping effect are the contact springs 42 diagonally in the connection cap 39 arranged. These are turned contacts to which the individual strands of the cable 38 crimped. The contact springs 42 are in the formed as a molding connection cap 39 cast.

About a coding element not shown here in the form of a coding groove on the board 12 , on the sensor housing in the form of the outer tube 26 and on the connection cap 39 is a correct insertion and reverse polarity safe operation of the connection cap 39 on the board 12 guaranteed.

For mounting the sensor 1 The procedure is as follows. First, the board 12 with two sensor circuits according to 1 and the equipment according to 6 and 7 produced. The board 12 is then bent over so that the first fiber optic card area 18 at the second fiber optic card area 19 is applied. In this state, the two half-shells with respect to the board 12 positioned and put together. This is the permanent magnet 33 between the two cap shells 30 inserted. In a preferred embodiment, adhesive may be in the area between the two cap shells 30 be introduced. After the adhesive has cured, the part of the probe that has been completed in this way can be replaced 1 be tested for its mechanical and electrical function.

Subsequently, the board 12 in the outer tube 26 inserted. The graduation cap 27 gets over from the two cap shells 30 formed retaining cap 29 slipped up until the locking lugs 31 in the detent openings 32 snap into place as it is in 8th is shown. Subsequently, the Börtelbereich 36 crimped. Then the sensor becomes 1 checked. For final assembly, the connection cap 39 on the board 12 attached and the crimping area 41 crimped.

In an embodiment not shown here, the connection cap 39 also be designed as angled connection cap.

Behind the plastic cap 27 a carrier board is integrated, which serves among other things to accommodate the coils. On this carrier board, a sense strip is applied per encoder.

10 shows a schematic diagram of a second sensor according to the invention 1' , The sensor 1' agrees in essential parts with the probe 1 out 1 match. Same components have the same reference numbers. The sensor 1' operates with a signal output terminal X102 at which a variable voltage level is output. At the ground connection X103, a system-wide ground is applied.

The Output signal of the sensor chip IC101 is the input signal an OP IC102 connected as a non-inverting amplifier with rail-to-rail exit. Determine resistors not shown here the reinforcement of the OP IC102. Furthermore is a resistor as a protective resistor against EMC interference and for reducing the power of the amplifier in the event of a short to the Output pins provided.

Switches the output transistor of the sensor component IC101 due to a stimulus to the Hall probe 3 gem. 2 , the output "1" of the OP IC102 switches to "Low." This means that the output voltage pin X104 of the encoder has a low signal (0V).

If the output transistor of the Hall sensor IC101 blocks, the OP IC102 switches to "High" due to a pull-up resistor (not shown) .Thus, the output voltage pin X102 of the encoder has a "High" signal (U _b ).

The OP IC102 (IC202) offers the possibility of a limited current at the output pin X102 of the probe 1' to flow. This case is called "level adjustment".

The sensor 1 and the probe 1' can be built with the same board, if it is provided for tracks and jumpers. To start from the sensor 1' to the sensor 1 At first, the IC102 is simply omitted. The ground connection X102 is connected to the system ground. In the points "B" and "C" in 10 a jumper is replaced by the zener diode D107. The resistor R101 is replaced by the resistor R121, and the resistor R119 is coupled with the transistor T105 between the points "A", "C" and "D" in FIG 10 connected.

Another application arises when starting from the probe 1' out 10 a measuring sensor, not shown here, is provided which has a so-called "transistor output". By means of appropriate bridge wiring and reduced provision of the printed circuit board, it is possible to use the output signal of the sensor component IC101 directly as an output signal of the sensor, which is applied to the output terminal X102. The X103 connector is used instead as the system ground GND. The driven output transistor of the sensor 2 provides a "low" signal, pull-up resistance between terminals "1" and "2" provides a high output signal at a locked output transistor of IC101. In addition, a resistor between terminal "2" of IC101 and terminal X102 can function as a protective resistor against EMC interference and also serves to reduce the short-circuit current at the output pin.

11 shows a schematic diagram of a portion of a third sensor according to the invention 1'' , The sensor 1'' is configured so that it emits a so-called "center voltage" as a function symbol when it indicates the standstill of a vehicle during operation: In order to detect an interruption or a short circuit of the connection pins of the transmitter, the train becomes stationary during the pulse with the center voltage output of the quiescent level set to a value between 6V and 8V.

in the Normal operation (train drives) the pulse generator outputs a frequency signal whose voltage value between 0V and the supply voltage changes.

There a part of the circuit for the center voltage generation, namely the monoflop IC105 and the analog switch or MUX / switch IC104, works with 5V, using the resistor R116 and the 5V reference Zener diode D111 from the supply voltage Vs for these devices a supply voltage generated by 5V.

On the Resistor R101 and Zener diode D110 will be the output of the Sensor IC101 (open collector - output "2") to a level between 4.7V (output transistor the sensor locks) and 0V (output transistor of the sensor conducts) limited. As a result, the npn transistor T107 is driven. About one not shown resistor, the capacitor C112 is discharged. This occurs on each rising edge of the IC101 delivered Frequency signal. A diode not shown here limits negative Switching peaks at the falling edge of the frequency signal arise. If the drive of the npn transistor T107 remains off, thus, the capacitor C112 can charge via the resistor R127.

The switching time t _{1 of} the monoflop results from the value R127 and C112 according to the equation t 1 = In3 · R · C

If the transistor T107 before the time t ₁ again conductive, the monoflop is reset (retriggerable). Normally (driving), the monoflop is continuously triggered, so that the output of the IC105 remains at "High" (5V) .If there is no retrigger (train stop), the output goes to "Low" (0V), as in 12 is illustrated in the middle curve on the right.

The output of the monostable IC105 drives the analog switch IC104. At a "high" signal (ie driving operation detected) at the control input "1" of the analog switch IC104 whose input "6" or the frequency signal of the sensor 2 connected to the following "+" input of the OP IC102. In the case of a tie-break, the voltage set via the voltage divider R135 and R138 is present at the OP IC102, because the switch IC104 passes the signal present at its input "Pin 4". This results in a so-called "pre-emphasis voltage." The final resulting center voltage is determined by means of the gain of the OP IC 102. The gain is set by the resistors R103 and R100 The amplification factor was chosen so large that the clamped to 4.7V internal sensor signal at the sensor output X102 is safely in the range of 0V to U _b For the center voltage, this means that it assumes a nominal value of about 7 V. A resistor (not shown here) at the "pin 6" output of the OP IC102 is a protective resistor against EMC interference and also serves to reduce the power of the amplifier in the event of a short circuit at the output pins X102 and X103.

13 shows a block diagram showing the functional units of the probe 1 to 1 and their interaction is illustrated. How to be particularly good in 13 sees, is additionally a protective circuit 11 provided, which includes reverse polarity protection and EMC protection.

14 shows a block diagram, the sensors after 10 and 11 and another sensor. In addition, a protective circuit 11 provided, which includes reverse polarity protection and EMC protection.

How to be particularly good in 14 sees, the arrangement according to the invention is chosen so that the modules "center voltage", "level adjustment" and "transistor output" can be provided by simple placement measures on the same circuit board.

1 ', 1' '

probe

2

sensor

3

Hall probe

4

power source

5

destruction detector

6

Sens-conductor track

7

Flip-flop

8th

Sensor test circuit

9

stimulus coil

10

Security

shutdown

11

protection shutdown

12

circuit board

13

first rigid lei

terplattenbereich

14

second rigid

Leiterplattenbe

rich

15

flexible ladder

plate area

16

polyimide film

17

conductor path

18

first glass fiber

card business

19

second glass fiber

card business

20

centering knobs

21

centering

22

Sensor stimulator

23

solder resist layer

24

cover sheet

25

contact tongue

26

outer tube

27

end cap

28

O-ring

29

retaining cap

30

cap shell

31

locking lug

32

latching opening

33

permanent magnet

34

Edge protection bar

35

guide rail

36

rollover

37

Passageway

38

electric wire

39

connection cap

40

O-ring

41

rollover

42

contact spring

Claims (5)

Sensor with a circuit board which can be inserted into a housing ( 12 ) with a first rigid circuit board area ( 13 ) and with a second rigid printed circuit board area ( 14 ) and with a flexible printed circuit board area extending from one end of the first to one end of the second rigid printed circuit board area (US Pat. 15 ), wherein the first rigid circuit board area ( 13 ) and the second rigid circuit board area ( 14 ) are arranged adjacent to each other and on a bending line of the flexible printed circuit board area ( 15 ) at least one sensor component ( 22 ) is arranged, and exposed interconnects ( 25 ) at the flexible printed circuit board area ( 15 ) opposite end of a rigid circuit board area ( 13 . 14 ) are provided with connections. Sensor according to claim 1, characterized in that connecting elements ( 20 . 21 ) for the fixed connection between the first rigid printed circuit board area ( 13 ) and the second rigid circuit board area ( 14 ) are provided. Measuring sensor according to claim 1 or claim 2, characterized in that the housing with guide rails ( 35 ) is provided for the first and the second rigid circuit board area. Measuring sensor according to one of claims 1 to 3, characterized in that in the region of a contact edge of the printed circuit board ( 12 ) open conductor tracks ( 25 ) are provided on the first and / or on the second rigid printed circuit board area, to which an electrical connection socket ( 39 ), whereby the connection socket ( 39 ) at least one spring contact area ( 42 ) which on the one hand comes into contact with one of the two rigid printed circuit board areas and on the other hand with a conductor track on the other rigid printed circuit board area. Measuring sensor according to Claim 4, characterized in that the spring contact region has two opposing clamp contacts ( 42 ), which against an inserted therebetween printed circuit board ( 12 ) are formed resiliently displaceable.