DE1588958A1 - Fault system for capacitive responsive circuit - Google Patents

Description

concerning
Sensor system for capacitively responsive circuit

The present invention relates to a sensor system for a capacity change responsive Circuit, especially for use in controlling the flushing process of toilet facilities.

The automatic actuation of flush valves in Urinals and other sanitation is desirable for many reasons. In some automated systems a conductive plate mounted above the urinal was used to detect the presence of a user as a result of the ascertain increased capacity through his body capacity.

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1588953

However, this device has the disadvantage that, without the presence of an object or a user in the vicinity of the sensor device, its remaining capacity to earth due to its inevitable close proximity to earthed parts of the urinal or the sanitary facility, such as water pipes and flushing valves, is fairly high is big, about 80pF. The change in the capacitance of the sensor device to earth caused by a person using the urinal or the sanitary facility is only one picofarad or less, ie a maximum of only 1 or 2 percent, and such a small change entails serious problems with regard to sensitivity and stability of the device that it is practically useless. For example, this device can work for adults, but temporarily fail if the sanitary facility is visited by users of small stature.

The object of the present invention is to create a sensor system for capacitively responsive circuits, which avoids the disadvantages of the known devices and a higher sensitivity and stability of the capacitive responsive circuits causes.

This object is achieved according to the invention in that an electrically conductive Pühlereinriohtung is provided, which both a first plate and a first capacitance

009841 / U55 ORIGINAL BATHROOM

as well as a first plate of a second capacity, wherein the second plate of the first capacitance is formed by an object which is in a predetermined, in the Near the sensor and the second plate of the second capacitance from an electrically conductive, a larger circumferential element is formed, which is arranged in the vicinity of the sensing device.

The electrically conductive element to which a voltage potential is applied by the associated circuit interrupts a large part of the field lines between the sensor device and earth or the earthed parts the sanitary installation, reducing the remaining capacity of the sensor device to earth to around 15 to 30 picofarads is decreased. This ensures that the increase in the capacity of the sensor device to earth, which is caused when a person uses the urinal or sanitary facility, a larger percentage represents the remaining capacity of the sensor device to earth, so that a greater change is obtained, the has an advantageous effect on the sensitivity and stability of the associated circuit. Naturally there is a large capacitance between the electrically conductive element and earth. However, this capacity is annoying not determining the presence of a user

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of the sanitary facility, since this capacity depends on the area in which the sensor device detects the presence of a Person realizes is disconnected. In addition, the capacitance between the Pühleinrichtung and the electrical conductive element can be quite large without causing any disadvantages or problems as this capacitance remains constant and is connected to the associated circuit and by adjusting other components of the Circuit, e.g. of resistors, can be compensated. Therefore, the use of the invention results in a electrically conductive element having a larger circumference, which is arranged in the vicinity of the sensor device and its dimensions correspond at least approximately to the dimensions of the sensor device, a reduction the remaining capacity of the sensor device to earth, which is a significant advantage and disclosed Sensor system for capacitively responsive circuits to control the flushing process in toilet facilities, commercial makes applicable.

Advantageously, the sensor device extends only over an area that is smaller than half of the is electrically conductive element, so that it is particularly good against nearby grounded parts by the latter is shielded.

ο 0. ^; 1 / U 5 5

The sensor system according to the invention is preferably connected to circuit elements in order to electrically
conductive element with an electrical potential
Mistake. A coaxial cable can be provided, the inner conductor of which is electrically connected to the sensor device and
whose outer conductor is electrically connected to the electrically conductive element and which forms part of the second capacitance, the sensor device and the
electrically conductive element through the coaxial cable
the remaining part of the capacitive responsive circuit are connected.

The sensor device is preferably in the form of a grid or alternatively in the form of rods arranged in an isolated manner. The capacitance is between the electrical conductive element and the grid or the bars due to the open spaces in the grid or between the individual bars of low value. The capacitance between the grid or bars and one at some distance however, the user located off the grid is about the same as between a user and a compact disk. This arrangement is relatively sensitive and can detect the presence of a person at a noticeable distance.

009841/1456

The electrically conductive element can be arranged in the immediate vicinity of a grounded water film - whereby a capacitance is created between them and the disruptive influence of the water film occurring during rinsing is reduced.

The capacitively responsive circuit is preferably designed in such a way that the two capacitances are charged and the size of their charges is compared, and the result of the load comparison of the two capacitances e ^ n output signal of the circuit is generated.

The sensor system can have a two-branch discharge circuit, one of the two capacitances being discharged in opposite directions via the one and the other of the two capacitances via the other of the two individual branches. _;

The circuit generating an output signal can be followed by an amplifier system with a relay which supplies current to the load when an output signal is generated at the circuit. The amplifier system can include a timer to cut off the relay from the power supply after a predetermined period of action. A coupling circuit is expediently provided which prevents the relay from being

009841 / U-5 5 ■

BATH ORIGINAL

correct actuation time cut off from the power supply

The relay can operate a pair of contacts that the Load connects to an alternating current source, where the coupling circuit comprises a series-connected rectifier diode which is one of the connection contacts for connects the load to an actuation circuit to ensure that the power source is compatible with the load remains connected during said actuation time.

One of the individual branches of the discharge circuit can be connected to the outer conductor of the coaxial cable, that connects the PUhIeinrichtung with the circuit. The electrically conductive element can be arranged to the side or in front of the area of use of the sanitary facility and be within an enclosure or partition that separates multiple sanitary facilities, wherein the sensor "is arranged adjacent to the electrically conductive element and isolated from it.

In the following the invention is explained in more detail with reference to schematic drawings of exemplary embodiments. It yeigen:

009841 / U55

Fig. 1 is a schematic circuit diagram from which it can be seen is the way in which a capacitively sensitive element forming the sensor device Grid with two output contacts coupled to a flush valve or a motor can be coupled to trigger a flush valve j

2 shows a schematic circuit diagram of an alternative coupling device in which the switching elements are fixed at some distance from the sensor system;

5 is an isometric view of a urinal with another embodiment of the sensor system;

FIG. 4 is a plan view of that shown in FIG Urinal;

Fig. 5 is a cross-section through that shown in FIG. J> urinal along line 5-5 and

6 shows a circuit diagram with two different connection schemes, to compensate for the capacitive effects created by a grounded film of water in the sanitary facility.

0 ö 9 6 - / U 5 5

Like from Pig. 1, the system includes an electrically conductive element in the form of a flat plate 10 attached along the area intended for users. The plate can be of larger size and be 0.60 m (2 ft) wide and 1.21 m (4 ft) high. An electrically conductive one Sensor device is attached in the form of a conductive grid 11 parallel to the plate 10, the distance may be about 12.7 mm (0.5 inches) from the plate. This

Sensor system, hereinafter also referred to as capacitively sensitive Device is designated, comprises a leakage or earth capacitance 12 between the screen 11 and earth, wherein the latter in this case by the floor or the usual Fittings is shown that conduct. When a user is in front of the sanitary facility, will through his body also a capacity 13 between Shield and earth are formed and this additional capacitance actuates the circuit and triggers the purge valve afterwards the user has left the urinal.

In Figs. 1 and 2 let a perforated grille and a perforated screen is shown, as this type of probe or electrode is easily applicable and over an extensive

009841 / U55

1588983

Area of activity has. However, many other types of electrodes can be used. Several small plates or a multitude of sticks attached either horizontally or vertically serve the same purpose.

An oscillating circuit is connected to the plate 10 and the grid 11, which contains a small neon or glow lamp 14

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and two resistors 15 and 16 connected in series between plate 10 and ground. One of the lamp electrodes is connected to a sliding contact 17 of a resistor 18 which is connected between the resistors 15 and 1 $. The resistor 18 can be bridged by an additional resistor 20, but this is not always necessary. The other connection contact of the lamp 3A is connected to the grid or screen 11. The grid is also connected to a line 21 via a limiting resistor 22. The line 21 is connected to a negative voltage source, which in the present package is formed by the diode 25 and a capacitor 24. These switching elements are connected to connection contacts 25, 26 for a power source and can be connected to an alternating current network of approximately 117 volts. The circuit described above is designed as an oscillator and comprises a first capacitance 19 between the plate 10 and the grid. A second capacitance 12 is formed between the grid 11 and earth. These two capacitors are charged when a negative voltage is applied to the line 21. During the charging via the resistor 22, the voltage at the lamp connection contacts increases until the ignition voltage is reached, whereupon the lamp conducts and the voltage at its connection contacts up to a value below the glow voltage is reduced. This

009841/1455

Operation allows the capacitor 19 to discharge, around in the direction of arrow 27 a current pulse in the resistor 15 to produce »The discharge of the capacitor 12 causes a similar current pulse in resistor 16, However, in the opposite direction to arrow 23. if The © Ulderstands 15 and 16 are the same and the capacities 12 and 19 have the same capacitance value, there is none at the external connections of the resistors 15 and 16 AC voltage, since the two opposite one another Compensate the voltages generated by current mini pulses.

When a user approaches the sanitary facility or the urinal, an additional capacitance IJ is connected between the grid 11 and the earth line 20. This causes the oscillator to apply a series of uncompensated pulses to resistors 15 and 16. In the present case, the pulses through the resistor are Lö stronger than the pulses emitted to the resistor 15, so that a negative voltage is present at the upper end of the resistor 15. A number of different coupling circuits can be connected between the resistors 15 and 15 and a pair of output contacts 21 and 22, which can be connected to a load circuit. The coupling circuit described here has two transistor amplifiers yβ vmä ; & * a semiconductor solenoid 25>

1 / U 5 5

15889Ü8

first relay J6 and a second relay J7. These most important switching elements are interconnected and in this way ensure a very specific one Effective / effective.

The first amplifier, ie, the transistor JJ, has its emitter connected in series with the ground line JO through a resistor 38 . The emitter is also coupled to the base of the transistor? 4 via a capacitor 40. The collector of the transistor y $ is connected to a voltage divider which comprises the resistors 41 and 42. The base of the transistor Jh is connected to a voltage divider comprising resistors 4, 5 and 44 on one side and resistor 45 on the earth side, whereby the voltage at the base is partially stabilized. The emitter of the transit gate? 4 is connected directly to the ground line JO, while the collector is connected to the negative line 21 connected in series with the resistor 45. The collector of transistor j4 is via a. small capacitor 46 is connected to a switching device 25 consisting of two transistors. This switching device comprises a first pnp transistor 47, the emitter of which is connected to an alternating current source connected in series with the resistor 48. The emitter of the second npn transistor 50 is connected to the ground line 20. This switching combination is the base of every © β transistor

009841 / U5B

- 10 -

ft

connected to the collector electrode of the other transistor, the base of the transistor 50 with the FoppellvOndsator

46 is connected. The base of transistor 50 is also connected to an automatic voltage circuit which a resistor 29 and a capacitor 39 comprises. This circuit is in the German patent 1,293,847 of the Anmalderin described. Negative pulses from the supply line 21 connected to the mains connection contact 25 are through the emitter-collector electrodes of transistor 35 let through when the Zener voltage is exceeded, and charge the capacitor 39. The capacitor lM.dk itself until the Zerar voltage of transistor 50 is reached. Additional voltage is diverted to ground line 30.

The output of the switching device 35, which has two transistors, is via a diode 51 with a winding 52 of relay 36 coupled. There is a large one about the winding 52 Capacitor 53 connected in parallel so that it can take effect on the basis of pulses without fluttering or fluttering. To cause hitting the anchor. The armature of the relay 36 is directly connected to the terminal 25 of the alternating current source tied together. When the relay is not energized, a top pair of contacts 54 is closed, causing current to pass through a

QQ9841 / U55

-ar-

AS

Resistor 55 vaaA a lamp 56 flows to the other side of the connection terminal of the power source. When the relay is energized, a lower pair of contacts 57 is closed and alternating current is applied to the line 58, which is connected to the collector electrode of a transistor 60 and via the diode 61 to the winding 62 of the second relay 37. A large capacitor 63 is also connected in parallel with this relay winding so that it can take effect without the relay vibrating or fluttering when short pulses are applied to it.

The relay yj further comprises an armature which is connected directly to the terminal 25 of the AC power source. When the relay is energized, normally open contacts 64 are closed and terminal 25 of the power source is connected to terminal j51 of the load circuit. At the same time, the alternating current source is connected by means of the line 65 to the winding 52 connected in series with a limiting resistor 66 and a diode 67.

The transistor 60 is directly with its collector the line 58 and to its base with a delay circuit 68 connected, which comprises a first capacitor 70 and a second capacitor 71. The capacitor 70

- 12 - 0 0 3 8 / ι 1 / U! "5

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Jl

let through the resistors 72, 7? and 7 ^ switched that are in turn connected in series. The capacitor 71 is connected across the resistors 75 and 7 ^. A diode 75 is connected between the line 58 and the connection of the capacitor 70 to the resistor 72. Of the The purpose of this delay circuit is described below.

The mode of operation of this circuit is as follows «

It can be seen that the oscillator circuit, which comprises the lamp 14 and the chargeable capacitors, oscillates continuously as soon as the negative voltage is applied to the line 21. When there is no user in the immediate vicinity of the grid or screen 11, there is essentially no output voltage at the base of the transistor Jft , since the output voltages compensate each other. No pulses are fed to the transistor 24 and the halter switching device 55 does not receive any pulses either, so it is not conductive and the first relay 26 receives current through the resistor 48 and the diode 51, so that it is excited and the armature is attracted and thereby the contacts 57 are closed, as shown in the drawing. The lamp 56 does not ignite, but power is present on line 58 and delay circuit 68. Negative·

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/ 11

Current pulses now flow through diode 75 # to charge capacitor 70 to approximately 150 volts and capacitor 71 to approximately 40 volts. Since the base of the transistor 60 is connected to the junction of the resistors 73 and 74, it is kept at a low forward voltage, the transistor 60 is conductive and bridges the winding 62 of the relay 37 so that the contacts 64 remain open. The values of the resistors 72, 73 and 74 as well as the capacitors 70 and 71 are dimensioned so that it takes about five seconds until these capacitors are charged to a negative voltage, so that a low negative voltage is applied to the base of the transistor 6o and this causes the winding 62 to be bridged by the transistor 60 and an opening of the contacts 64 is made possible, whereby the voltage to the connection contacts for the load is interrupted. This five-second interval was chosen because the flushing process takes about five seconds. It is obvious that such a circuit also enables any other time interval if an adaptation to other processes is desired.

Let us assume that a user is approaching the sanitary facility and his body capacity increases to the capacity 12 which normally exists between grids and ground. This increased capacity, which is perhaps only three ttkofar & d «

009841/1455 - ** -

causes a significant change 1 "oscillator circuit and the current flowing through the resistor 15 current is substantially less than the current flowing through ύ m resistor X6 current · As a result, the base will be dee first Tranaistors negative pulses asserted * dl« «« pulses are IMD amplified negative Throw pulses across the capacitor 40 of the base of the second transistor JK . As a result, amplified positive pulses are generated, which are fed to the switching combination 3p i & er den .Kondensator 46, whereby this becomes conductive and the winding 52 of the relay J6 short-circuits, so ö & S the contacts 57 are opened and the contacts 5 ^ are closed. This disconnects the line 58 from the AC voltage and lights up the lamp 56

When the line 58 is disconnected from the voltage, the capacitors 70 and 71 discharge through the resistors 72 »7? and 7 ^ in about 12 seconds and the base of transistor 60 is trains a more positive voltage * leads to make it non-conductive * Since the contacts 57 are open, the coil 62 may be the relay yj However, no current is supplied, so that the contacts 64 remain open and the load is not energized. As long as the first relay 36 remains in the de-energized state, the second relay cannot generally take effect. This means that as long as a user is in the immediate vicinity of the «

- 15 -

009841 / U55

Grid »11 is located, the load is not actuated and no rinsing process takes place.

It is now assumed that the user has the sanitary facility leaves and thus the additional capacity 13 »taken away and the normal state of the Oscillator system is restored. It is now no voltage on transistor holding device 25 on, the switching device 25 is non-conductive and the first Relay winding 52 receives power, which turns the lamp $ 5 off. AC voltage is applied to line 58 and negative pulses are fed to winding 62, so that the relay 27 becomes effective and the contacts 64- closed will. The load is now supplied with current, the motor (not shown) for the flushing is activated and the rinsing process is triggered. The motor works about five more seconds until capacitors 70 and 71 are charged to a voltage equal to that of the base of transistor 60 is given a negative 20 volt bias. This causes the transistor 60 to conduct and the winding 62 to be short-circuited to the contact 64 to open and cut off the power supply to the motor.

The circuit described above could trigger an early flush if the user moves away

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009841 / U55

to

and returns within five seconds. In this case, the switching device comprising the two transistors would be placed in a state in which it would let current through and short-circuit the first relay. To ensure that this does not happen, a susatz circuit is provided which comprises a line 65, a resistor 66 and a diode 6 * 1. As long as the contacts 6k are closed, the relay winding 52 is connected to the terminal contact 25 via the contacts 64, the Line 65 and diode 67 are supplied with current, the contacts 57 remaining closed, regardless of the state in which the switching device 25 is * This means that the load motor can continue to operate for the predetermined five seconds to end the flushing process. This interlocking circuit protects against overflow that could be caused by a person moving back and forth. A second user can also approach the sanitary facility within 17 seconds without triggering premature flushing. In the absence of an interlocking circuit, flushing would start again and result in undesirable wet spraying by the user.

The circuit shown in Figure 2 is an alternative Arrangement of the capacitively sensitive device. This is the same capacitively sensitive one

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0098A1 / U55

«A

Device as shown in FIG. 1, except that a conductive concentric cable 76 is used to shield the line ff which connects the grid 11 to a socket contact of the lamp 14. The cylindrical shield 78 is connected at one end to the plate 10 and at the other end to the base of the first transistor 22 must be arranged by the grid. The additional funds according to Pig. 2 cause an increase in the capacitance between plate and grid «Both the charging current and the discharging current are increased, but the circuit can easily be balanced again by moving the sliding contact 17 or by changing one of the two resistors 15 and 16 the same as the mode of action of the in Flg. 1 circuit shown.

In Figures 2, 4, 5 and 6 there is a different implementation a sanitary device 80 shown, which consists of porcelain or similar material and a has flat rear part and protruding side parts 81 and 82. This shape allows a different arrangement of the capacitively sensitive electrodes within the sanitary facility, which is invisible to the user, one

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compact conductive rear plate 10A (corresponding to plate 10 in Pig, 1) forms part of the capacitively sensitive system and serves to compensate for a grounded water film. Two conductive rods 82 and 84 replace the one in Pig. As a result of the position of these capacitively sensitive electrodes, one must take into account the film of water 91 which may appear during the use of the sanitary facility. Since the water flows into a metal drainage pipe, the water film is earthed and a considerable capacitance is created between the shield and earth 20. An additional capacitance 92 arises between the rods 8j and 84 and the water film 91. The stray or earth capacitances between the rods and earth are shown in PIg ο as capacities 85 and 86.

In most sanitary installations of this type, the control circuit should be located at a distance from the sanitary installation where it cannot be sprayed wet and where it is difficult for the user to damage it. Such systems generally require a shielded cable 76 with a central line 77 as shown in Figs. A small leakage or earth capacitance is always present in such a line, and this capacitance is

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that the discharge lamp 14 is connected between the concentric line 77 and the center tap located between the two resistors 15 and 16, becoming part of the oscillating circuit. When the lamp 14 ignites, part of the current flows via the lines 87 and 77 to the rods 85 and 84, via the stray capacitances 85 and 86 to the earth line j30 _# the resistance Ιβ and to the other side of the lamp 14 · Another part of the discharge current flows via lines 87 and 77 and cable capacitance 88 to line 90, resistor 15 and to the other side of the lamp. If these were the only discharge paths, an adjustment of the resistor 16 ^{f is} possible to compensate for voltage drops, so that the output voltage is essentially cool when there is no user in the vicinity of the bars.

The water film 91 exists temporarily and is always grounded. There is a certain slight capacitance 92 between the capacitively sensitive rods 83, 84 and the water film 91. When this capacitance increases, the discharge pulses flowing from the lamp 14 via the line 77 increase and the voltage drop across the resistor 16 increases which increases the output signal. The capacitance 92 is parallel to the capacities 85 and 86 and tends to reduce the sensitivity. "This deficiency can be partially compensated by * dafl dl"

009841 / U55 -20-

Plate 1OA is placed directly behind the water film in order to increase the capacity between plate and earth, When switch 94, as in Pig. 6 shown in its upper Is brought into position, the capacitance 92 conducts part of the discharge current, which normally flows from the cable shield via the resistor 15, via the capacitance 92 to the earth line and via the resistor 16 from «

The presence of a user, represented by the capacity 12, increases the discharge flow the resistor 16 and causes an uncompensated voltage which amplifies and in the same way as In Connection described with Fig. 1 is used.

Another balance is achieved by connecting the eye arm 94 to its lower contact. The one part the discharge current of the lamp then flows through the cable, via the line 77 to the capacitively sensitive rods 82 and 84, via the capacitors 92 and 92 via the resistor stood on the other side of the lamp. Resistance 15 can be set so that there is no output voltage if there is no capacitance 12 (i.e., no user) located in front of the bars. If a capacity 12 is added, causes the discharge current flowing through the resistor 16 * the desired uncompensated voltage and it becomes a Output signal generated.

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IS

It can be seen that the switching arrangement described above can be set so that either positive or negative discharge impulses arise. When such a change is made, the number of amplifier stages can be changed to produce an unchanged directional signal for the load circuit. But it can The polarity of the coupling circuit that excites the relays in order to feed the load can also be reversed.

The capacitance between the sensing device 11 or 83 and Sh and the electrically conductive element 10 can be quite large without causing any disadvantages or problems, since this capacitance remains constant and is connected to the associated circuit and by adjusting other components of the circuit, For example, the resistances 15> 16, 18 and 20, can be compensated.

The features disclosed in the application documents and details are, insofar as they are new to the state of the art, individually or in combination, as essential to the invention claimed.

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Claims (1)

-äMA! 197O WAGNER EEBOTRIO CORPORATION My reference »1A-1982 Proposal for new claims 1 »Sensor system for capacitive responsive circuit, especially for use in controlling the flushing process of toilet facilities, characterized that an electrically conductive sensor device (11} 85 »84) is provided which has both a first plate a first capacity (12; 85 »86) and a first plate a second capacitance (19), the second Pj rfcte the first capacity (12 $ 85 »86) of an object gebi" jt which comes in a predetermined area located in the vicinity of the sensor (11; 83 »84) and the second plate the second capacitance (19) is formed by an electrically conductive element (10, 10A) having a larger circumference near the sensor device (111 83, 84) is arranged. 2. Sensor system for capacitively responsive circuit according to Anspruoh 1, characterized in that the sensor device extends over an area which is smaller than half of the electrically conductive element (10, 10A). 3. Sensor system for capacitively responsive Sohaltkreie naoh claims 1 or 2, characterized by .luc documents m-ιi 1 «. , '■■ > »■ ι s- * π *.: & **«, »* v. 0098A1 / U55 Circuit elements (14, 15 * l6 »76) to the electrical conductive element (10 «10A) with an electrical potential to provide. 4 «sensor system for capacitively responsive circuit according to one of claims 1 to?, characterized in that a coaxial cable (76) is provided, its inner conductor (77) electrically with the Fühlereinriehtung (llj 83, 84) and its outer conductor (78) electrically connected to the electrically conductive element (10-10A) and that the coaxial cable (76) forms part of the second capacitance (19) and the powder device (Uj 83, 84) and the electrically conductive element (10, 10A) through the coaxial cable (76) with the remaining part of the capacitively responsive Circuit are connected. 5. FUhlersy star for capacitively responsive circuit according to one of claims 1 to 4 «thereby g β k e η η -seich net that the sensor device (U) is lattice-shaped» 6 * sensor systems for capacitive responsive circuits According to one of claims 1 to 4, characterized 9 in that the powder device is isolated from arranged bars (83 * 84) consists of 7 «FUhlersy stern for capacitively responsive circuit according to one of claims 1 to 6, since g β k · η η · shows that the electrically conductive element (10A) is in the immediate vicinity of an earthed film of water (91). net 1st, whereby a capacity (92) is created between them, 8. FUhlersyetera for capacitive responsive circuit According to one of Claims 1 to 7, »characterized« in that the capacitively responsive circuit 009841/1455 let designed so that the two capacitors (12; 19) are charged and the QrOBe of their charges is compared, and the result of the charge comparison of the two capacitors (12; 19) generates an output signal of the circuit 9. Sensor system for capacitively responsive circuit according to Claim 8, characterized in that that a two-branch discharge circuit is provided, one of the two capacitors (19, 12) via the one and the other of the two capacitors (19, 12) is discharged via the other of the two individual branches in opposite directions. 10. Sensor system for capacitively responsive Sohaltkreis according to one of claims 3 or 9 * characterized g β -indicates that an output signal generating the circuit is an amplifier system with a relay (37) is followed by adding electricity to the load " when an output signal is generated on the circuit. 11. Sensor system for capacitively responsive hold, Circuit according to claim 10, characterized in that the amplifier system comprises a timing circuit in order to cut off the relay (27) from the power supply after a predetermined period of action. 12 · Sensor system for capacitively responsive circuit according to claim 11, characterized in that a coupling circuit is provided which prevents the relay (37) from being cut off from the power supply during the predetermined actuation period. 13. Sensor system for capacitively responsive circuit according to Anspruoh 12, characterized by daduroh 09841 / U55 that the relay (JT) actuates a pair of contacts (64) «the connects the load to an alternating current source, the coupling circuit being a series-connected one Gleichrlohterdlode comprises "one of the connection con ·· connects clocks for the load with an actuating circuit »to ensure» that the power source with remains connected to the load during the specified actuation time " 14, sensor system for capacitive-responsive circuit NaOH any one of claims 9 to 13 "wherein j that one of the individual branches of the discharge circuit is connected to the outer conductor (7 &) of the coaxial cable (76) 'interconnecting the FUhlerelnriohtung (82» 84) to the circuit .