DE202020106475U1 - Flame detection for combustion devices - Google Patents

Abstract

A sensor arrangement for a combustion device, the sensor arrangement comprising:
a sensor (1) comprising a first and a second sensor connection, wherein the sensor (1) is designed to generate a signal offset between its sensor connections ^{in response to receiving a first amount of light of preferably 1.6 · 10 -3 watts per square meter,} and in response to receiving a second amount of light less than 1.6 x 10 ^-3 watts per square meter, generate equal signals at its terminals;
a differential amplifier (2) which comprises a first (7) and a second (8) supply connection, an output channel (3), an inverting (-) and a non-inverting (+) input channel;
a load element (6) which connects the output channel (3) to one of the supply connections (7, 8);
wherein the first sensor connection is electrically connected to the inverting (-) input channel and the second sensor connection is electrically connected to the non-inverting (+) input channel, so that the sensor (1) is designed to apply signals to the input channels (-, +) ;
wherein the differential amplifier (2) is designed to generate a current at its output channel (3) in response to the signal offset which is applied between the inverting (-) and the non-inverting (+) input channel, and the load element (6) is designed to dissipate a first amount of power as a function of the current generated at the output channel (3);
wherein the differential amplifier (2) is configured to draw a load current from the supply connections (7, 8) in response to the signal offset being applied between the inverting (-) and the non-inverting (+) input channel;
wherein the differential amplifier (2) is designed to draw a quiescent current from the supply connections (7, 8) in response to the fact that identical signals are applied by the sensor (1) to the input channels (-, +);
wherein the load current exceeds the quiescent current by at least fifty percent and the quiescent current is less than fifteen microamps; and
wherein the sensor (1) is selected from
a sensor consisting exclusively of a silicon carbide photodiode and the first and the second sensor connection or
a sensor comprising a silicon photodiode and the first and second sensor connections and at least one optical filter.

Description

background

The present disclosure relates generally to devices for flame detection in combustion appliances. In particular, the immediate disclosure relates to flame detection that is not based on CdS diodes.

Combustion devices for fossil fuels such as gas burners or oil burners generally rely on optical sensors that detect the presence of a flame. Signals received from these optical sensors are processed to ensure safe operation of the device.

Optical sensors that are suitable for flame detection have to meet a large number of contradicting technical requirements. They must have low dark currents in order to avoid false alarms. Suitable sensors must also be sensitive enough to detect small amounts of incident light such as 0.5 lux. In other words, the sensors and their detection circuitry must minimize both false positives (Type I errors) and false negatives (Type II errors). The additional requirement of inexpensive sensors exacerbates the problem.

Known sensors that are suitable for flame detection include cadmium sulfide (CdS) sensors due to the low dark currents. The use of such sensors in flame detection is widespread. In fact, due to RoHS (Restrictions on Hazard Substances) regulations, CdS photo resistors are about to be extinguished. Since CdS elements are being phased out, suitable replacement products must be found.

The Chinese patent CN101221071B was issued on October 6, 2010 and teaches a flame detection device. CN101221071B discloses a circuit having a light receiving element 11 and with a flame detector 20th . The light receiving element 11 comprises a Si photodiode and is connected to the detector via a cable 30 20th connected. A filter circuit 13 and a dark current adder circuit 12 are between the cable 30 and the light receiving element 11 arranged. The filter circuit 13 serves to minimize adverse influences due to noise. In addition, a diode prevents 14th Polarity reversal error.

At the 21st . September 2005 is the European patent EP0942232B1 granted. EP0942232B1 teaches a flame sensor with dynamic sensitivity adjustment. The revelation of EP0942232B1 focuses on flame detection in gas turbines.

A circuit with two amplifiers U1A and U1B is used to adjust the sensitivity dynamically. A silicon carbide (SiC) photodiode D4 is connected to the non-inverting input of amplifier U1A. The gain of the amplifier U1A is controlled by a switch Q1. When switch Q1 conducts, a resistor R4 is bridged. Since R4 is part of the feedback loop that controls the gain of amplifier U1A, Q1 also affects the sensitivity of the circuit. The amplifier U1B, in conjunction with a transistor Q2, converts the output voltage of U1A into electrical current.

The circuit of EP0942232B1 uses a silicon carbide (SiC) diode that detects (ultraviolet) light at wavelengths around 310 nanometers. EP0942232B1 uses several amplifiers U1A, U1 B and Q2, each of which can be the cause of errors. The specification of EP0942232B1 teaches connecting the flame detection circuit via a single pair of wires W1, W2. Wires W1 and W2 provide power to the circuit and also carry the output of the circuit.

The patent application DE2654881A1 was filed on December 3, 1976 and published on September 21, 1978. DE2654881A1 discloses a two-unit flame monitor. A first unit comprises a sensor and an amplifier. A second unit includes connections to the power supply and to a relay for a warning light. The relay for the warning light is connected to an output of the amplifier. A flame is therefore detected on the basis of a current at the output and not on the basis of a current at the input of the amplifier.

A European patent EP3339736B1 was registered on November 17, 2017 and granted on April 10, 2019. EP3339736B1 claims priority dated December 21, 2016. The European patent EP3339736B1 deals with the detection of flames in combustion devices. Specifically deals EP3339736B1 with an arrangement for the detection of flames, in which a diode made of CdS is dispensed with. The use of a diode made of silicon (Si) instead of a diode made of CdS is made possible, among other things, by an amplifier with a low quiescent current. The presence of a flame is detected on the basis of an increase in the electrical current which supplies the amplifier.

The present disclosure teaches a circuit for flame detection which dispenses with the CdS technology. The present The disclosure focuses on a circuit for use in fossil fuel combustion devices. The present disclosure further focuses on a circuit for use in combustion devices for hydrogen and / or mixtures containing hydrogen.

Summary

For pure hydrogen flames, flame monitoring according to the ionization principle is not possible, since there is no continuous conductivity from the ionization electrode to the burner in pure hydrogen flames. Therefore, other sensors have to be used for the task of flame detection, i.e. whether a flame is present or not.

The present disclosure makes use of the knowledge that in the ultraviolet (UV) range sensitive semiconductor sensors, due to their spectral sensitivity, fit very well to outstandingly with the emitted spectrum of a hydrogen flame. The sensitivity to the light intensity is lower than with UV tubes, but in the case of silicon carbide photodiodes it is relatively high. The service life is considerably longer than that of UV tubes. In addition, semiconductor photodiodes are much cheaper than UV cells.

The present disclosure provides an apparatus and / or circuit for indicating the presence of a flame in a combustion device. A differential amplifier is used for this purpose, which maintains (essentially) a zero voltage drop across a photodiode. That is, the photodiode is not reverse biased and does not operate in photoconductive mode. The photodiode is connected to the inverting input of the differential amplifier. The differential amplifier used in the circuit described below shows a quiescent current that is less than a permissible dark current.

Since the photodiode is not reverse biased, the dark current generated by the photodiode is minimized. Using a differential amplifier with a low power supply also reduces the risk of false positives. In other words, a differential amplifier with a low power consumption is used to prevent a flame from being displayed when there is no flame (type I error).

It is an object of the present disclosure to enable the sensitivity of the flame detection to be adjusted. In particular, this should take place in a combustion device.

A further object of the present disclosure is to provide a circuit which can be connected using a two-wire line.

It is a related object of the present disclosure to provide a circuit wherein a two-wire line provides a supply signal and also a signal indicative of the sensor output.

It is yet another object of the present disclosure to provide a solution that is backward compatible with existing solutions.

It is a related object of the present disclosure to provide a circuit that can be plugged into an existing combustion device. Existing sensors and / or sensor circuits can therefore be replaced.

It is yet another object of the present disclosure to provide a minimum supply voltage circuit.

It is still a related object of the present disclosure to provide a circuit for indicating the presence of a flame, wherein the differential amplifier is configured as an operational amplifier.

It is also an object of the present disclosure to provide a solution with a minimal zero point error.

It is also a further object of the present disclosure to provide a circuit for detecting the presence of a flame, in the case of which adverse influences due to (parasitic) leakage currents are minimized.

It is also the object of the present disclosure to provide a combustion device with a device for flame detection and / or with a circuit for flame detection according to the present disclosure. In particular, such a combustion device should be provided for fossil fuels and / or hydrogen.

Figure list

• 1 zeigt schematisch ein Schaltbild einer Diodenanordnung gemäss der vorliegenden Offenbarung.
• 2 zeigt schematisch eine Diodenanordnung, welche mit einer Versorgungs- und Detektionsschaltung verbunden ist.
• 3 zeigt schematisch eine Diodenanordnung, die von einem Brückengleichrichter gespiesen wird.
• 4 stellt die Emission einer Wasserstoffflamme dem Messbereich einer UV-Röhre gegenüber.
• 5 stellt die Emission einer Wasserstoffflamme dem Messbereich einer Silizium-Fotodiode gegenüber.
• 6 stellt die Emission einer Wasserstoffflamme dem Messbereich einer (mehrfach) gefilterten Silizium-Fotodiode gegenüber.
• 7 stellt die Emission einer Wasserstoffflamme dem Messbereich einer Siliziumcarbid-Fotodiode gegenüber.

Various features will become apparent to those skilled in the art from the following detailed description of the disclosed non-limiting embodiments. The drawings that accompany the detailed description can be briefly described as follows:

• 1 schematically shows a circuit diagram of a diode arrangement according to the present disclosure.
• 2 shows schematically a diode arrangement which is connected to a supply and detection circuit.
• 3 shows schematically a diode arrangement which is fed by a bridge rectifier.
• 4th compares the emission of a hydrogen flame with the measuring range of a UV tube.
• 5 compares the emission of a hydrogen flame with the measuring range of a silicon photodiode.
• 6th compares the emission of a hydrogen flame with the measuring range of a (multiple) filtered silicon photodiode.
• 7th compares the emission of a hydrogen flame with the measuring range of a silicon carbide photodiode.

Detailed description

1 shows a sensor arrangement with a sensor in the form of a photodiode 1 and with a differential amplifier 2 . The differential amplifier 2 includes inverting (-) and non-inverting (+) input channels. The two connections of the sensor 1 and / or the photodiode 1 are connected to the inverting (-) and the non-inverting (+) input channel of the differential amplifier 2 connected. In particular, the two connections of the sensor 1 and / or the photodiode 1 directly to the inverting (-) and the non-inverting (+) input channel of the differential amplifier 2 be connected. The anode of the sensor 1 and / or the photodiode 1 is advantageously connected to the non-inverting (+) input channel of the differential amplifier 2 connected. In particular, the anode of the sensor 1 and / or the photodiode 1 directly to the non-inverting (+) input channel of the differential amplifier 2 be connected. The cathode of the sensor 1 and / or the photodiode 1 is advantageously connected to the inverting (-) input channel of the differential amplifier 2 connected. In particular, the cathode of the sensor 1 and / or the photodiode 1 directly to the inverting (-) input channel of the differential amplifier 2 be connected.

In one embodiment, the sensor comprises 1 a silicon diode. In a special embodiment the sensor is 1 a silicon diode. In one embodiment, the sensor comprises 1 a silicon carbide (SiC) diode. In a special embodiment the sensor is 1 a silicon carbide (SiC) diode. In particular in a combustion device for the combustion of hydrogen or mixtures containing hydrogen, the sensor can 1 comprise a silicon carbide (SiC) diode. In a combustion device for the combustion of hydrogen or mixtures containing hydrogen, the sensor 1 be a silicon carbide (SiC) diode.

For the purpose of flame detection it is desirable that the sensor 1 has a low value of the parasitic parallel resistance. One from the sensor 1 and / or the photodiode 1 The photocurrent generated can otherwise be caused by the parasitic parallel resistance of the sensor 1 and / or the photodiode 1 are consumed. Low values of the parasitic parallel resistance are often associated with low values of the dark current I _R. It is also desirable to have a photodiode 1 with a small temperature coefficient to use. A small temperature coefficient makes the device and its circuit less sensitive to temperature changes in a combustion device. The temperature coefficient Tc of the short-circuit current Isc (at 25 degrees Celsius) is preferably less than 0.5 percent per Kelvin, more preferably less than 0.3 percent per Kelvin, even more preferably less than 0.1 percent per Kelvin or even 0.04 percent per Kelvin.

In addition, the sensor should 1 and / or the photodiode 1 have a spectral sensitivity λ _10% , which coincides with and / or overlaps with a signal originating from a flame in a combustion device. In an advantageous arrangement, the photodiode shows 1 a spectral sensitivity λ _10% between 200 nanometers and 900 nanometers, more preferably between 300 nanometers and 900 nanometers, even more preferably between 400 nanometers and 900 nanometers. The sensor advantageously shows 1 and / or the photodiode 1 at infrared wavelengths such as 900 nanometers a spectral sensitivity that is less than twenty percent, preferably less than ten percent, versus a sensitivity at 600 nanometers wavelength.

The sensor 1 and / or the photodiode 1 may be a VEMD5510 type diode in a particular embodiment. According to one aspect, the sensor is 1 and / or the photodiode 1 implemented as a surface-mounted device (SMD). Surface-mounted components enable low-cost, large-scale manufacture. Surface-mount components also enable miniaturized circuits.

The sensor 1 and / or the photodiode 1 ideally withstands elevated temperatures in a combustion device, especially elevated ones Temperatures in or near a combustion chamber of a combustion device.

The differential amplifier 2 amplifies the signal difference between its inverting (-) and its non-inverting (+) input channels. The differential amplifier 2 represents an output channel 3 ready for the amplified signal. The differential amplifier 2 is ideally an operational amplifier. According to one aspect, the differential amplifier is 2 implemented as a surface mount component. Surface-mounted components enable low-cost, large-scale manufacture. Surface-mount components also enable miniaturized circuits.

In another aspect, the differential amplifier is 2 an integrated circuit (IC).

The differential amplifier 2 advantageously shows a low value of the input bias current. A low value of the input bias current of the differential amplifier 2 gives advantages in terms of lower photocurrents that can be detected. The bias current of the differential amplifier 2 (at 25 degrees Celsius) is preferably less than 100 picoampere, but preferably less than twenty picoampere, even more preferably less than ten picoampere.

The differential amplifier 2 advantageously has a low value of the offset voltage. A low value of the offset voltage gives advantages in relation to low signals from the sensor 1 and / or the photodiode 1 .

The offset voltage between the inverting (-) and the non-inverting (+) terminals of the differential amplifier 2 (at 25 degrees Celsius) is preferably less than fifty millivolts, but preferably less than twenty millivolts, even more preferably less than ten millivolts.

It is also desirable that the differential amplifier 2 draws small currents. Otherwise it is difficult to detect small changes in the photocurrents due to small changes (increases) in the supply current. According to one aspect, the quiescent current of the differential amplifier is 2 at 25 degrees Celsius and with a nominal supply voltage less than five microamps, preferably less than two microamps, more preferably 1.2 microamps or less.

It can also be important that the differential amplifier 2 even with low supply voltages at its terminals 7th and 8th is working. Small supply voltages ensure that the in 1 The circuit shown can be connected to the terminals for conventional CdS arrangements. This means that the supply voltages of the in 2 differential amplifier shown 2 should be in the same range as the supply voltages of conventional CdS arrangements. The differential amplifier works at 25 degrees Celsius 2 preferably with supply voltages at its terminals 7th and 8th of only ± 3 volts. The differential amplifier works even more preferably at supply voltages of ± 2.5 volts at 25 degrees Celsius. The differential amplifier works even more preferably 2 with supply voltages of only ± 1.2 volts or even ± 1.1 volts at 25 degrees Celsius.

The sensor 1 and / or the photodiode 1 provides an anode connection and a cathode connection.

The cathode connection of the sensor 1 and / or the photodiode 1 is advantageously connected to the inverting (-) input channel of the differential amplifier 2 connected. The anode connection of the photodiode 1 is advantageously connected to the non-inverting (+) input channel of the differential amplifier 2 connected.

When the sensor 1 and / or the photodiode 1 is illuminated by a light source such as a flame, the sensor generates 1 and / or the photodiode 1 a photo stream. That from the sensor 1 and / or the photodiode 1 The signal obtained is then passed through the differential amplifier 2 reinforced. The differential amplifier 2 generated at its output terminal 3 a signal that is a function of the difference between the signals on its inverting (-) and non-inverting (+) input channels. In other words, the differential amplifier generates 2 at its output terminal a signal which is a function of the signal from the sensor 1 and / or the photodiode 1 generated photocurrent is.

In an advantageous embodiment, the differential amplifier is 2 an operational amplifier LPV812 of the type Texas Instruments @.

Due to environmental influences, signals can also be transmitted to the inverting (-) and / or to the non-inverting (+) input channels of the differential amplifier 2 build up. Such environmental influences are generally undesirable. The sensor arrangement should prevent such environmental influences from being affected by the sensor 1 and / or the photodiode 1 distinguish received signals and ambient noise.

The arrangement out 1 shows two impedances 4th and 5 , which are the input channels of the differential amplifier 2 connect with earth. The first impedance 4th connects the inverting (-) input channel of the differential amplifier 2 with mass. The second impedance 5 connects the non-inverting (+) input channel of the differential amplifier 2 with mass.

In one embodiment, the impedance is 4th a resistor, for example an ohmic resistor. The resistance 4th is chosen so that the resistance 4th in connection with the input capacitance of the differential amplifier 2 and / or in conjunction with a capacitor in parallel with the resistor 4th results in suitable RC time constants. The signal on the output channel 3 of the differential amplifier 2 can otherwise be caused by residual charges on the input channels of the differential amplifier 2 be disturbed. In one embodiment, the resistor 4th a specific resistance of less than 100 kiloohms (at 25 degrees Celsius), preferably less than twenty kiloohms (at 25 degrees Celsius), even more preferably less than ten kiloohms or even 4.7 kiloohms (at 25 degrees Celsius). The impedance 4th also holds the cathode connection of the sensor 1 and / or the photodiode 1 (essentially) at earth potential.

The sensor 1 and / or the photodiode 1 works at or near zero voltage. Consequently, all of the problems related to dark currents through the sensor 1 and / or the photodiode 1 occur, diminished. The impedances 4th and 9 determine the output signal of the differential amplifier 2 as a function of the photo current.

A photo current goes from the sensor 1 and flows through the impedance 5 according to mass. The potential at the non-inverting (+) input channel thus increases.

The differential amplifier 2 then generates equal signals on the inverting (-) and non-inverting (+) input channels by drawing an electrical current through the impedance 9 (and also through the sensor 1 ) drives. Hence the voltage drop across the impedance 4th the same as the voltage drop across the impedance 5 .

The input offset voltage determines the accuracy of the differential amplifier 2 and also the bias of the sensor 1 . According to one aspect, the impedance is 5 a resistor, for example an ohmic resistor. The resistance 5 is chosen so that the resistance 5 in connection with the input capacitance of the differential amplifier 2 results in suitable RC time constants. The signal on the output channel 3 of the differential amplifier 2 can otherwise be caused by residual charges on the input channels of the differential amplifier 2 be disturbed.

The resistance 5 can for example have a specific resistance of 2.2 megohms (at 25 degrees Celsius). The resistance 5 As another non-limiting example, it may have a resistivity of 4.7 megohms (at 25 degrees Celsius). The resistance 5 As yet another non-limiting example, it may have a resistivity of 6.8 megohms or even ten megohms (at 25 degrees Celsius).

By choosing suitable impedances 4th and or 5 the properties of the sensor arrangement can be adapted to the actual values of the photocurrent. As a non-limiting example, photocurrents can occur due to the light attenuation by a housing of the sensor arrangement and / or due to various sensors used 1 vary.

The impedance 5 advantageously results in a voltage rise at the output channel 3 without the need for additional reinforcement. Otherwise there would be a higher gain through the differential amplifier 2 required. However, higher gain levels have a detrimental effect on the offset voltage of the differential amplifier 2 out. An increased offset voltage would then worsen the inaccuracies and / or error signals of the arrangement.

Those skilled in the art understand that the characteristic of impedance 5 in can also be capacitive to a certain extent. Those skilled in the art also understand that a capacitive element is in parallel with a resistor 5 can be switched. The capacitive element is used to create a precisely defined capacitance between the connections of the resistor 5 to create. The capacitive element thereby contributes to a precisely defined RC time constant.

The impedance 6th connects the output channel 3 with mass.

The sensor 1 and / or the photodiode 1 generates a photocurrent under the influence of incident light.

The corresponding signal is sent through the differential amplifier 2 reinforced.

The differential amplifier 2 then generates a signal on its output channel that is a function of the photocurrent through the sensor 1 and / or the photodiode 1 is. Consequently, the impedance leads 6th a lot of (electrical) power. That amount is a function of the photo current through the sensor 1 and / or the photodiode 1 .

The terminals V +, 7 and V-, 8 of the circuit feed this amount of power to the differential amplifier 2 . The impedance 6th is chosen so that the power loss is within acceptable limits of the differential amplifier 2 lies. The impedance 6th is also chosen so that on the photodiode 1 incident light leads to a measurable increase in the supply current through the terminals 7th , 8th leads. The impedance 6th is preferably chosen so that two lux incident light result in a measurable increase in the supply current. The impedance 6th is furthermore preferably chosen so that a lux incident light results in a measurable increase in the supply current. The impedance 6th is even more preferably chosen so that 1.1 lux incident light results in a measurable increase in the supply current. The impedance 6th ideally, 1.6 · 10 ^-3 watts per square meter of incident light result in a measurable increase in the supply current.

According to one aspect, there is a measurable increase in the supply current (the power) through the terminals 7th , 8th at least five times the value of the quiescent current of the differential amplifier 2 . More preferred is a measurable increase in the supply current (power) through the terminals 7th , 8th at least twice as high as the value of the quiescent current of the differential amplifier 2 . A measurable increase in the supply current (power) through the terminals is even more preferred 7th , 8th at least half as large as the quiescent current of the differential amplifier 2 .

In a particular embodiment, oversampling leads to further improvements in the signal-to-noise ratio of the signal between the terminals 7th and 8th .

In one embodiment, the impedance is 6th a resistor such as an ohmic resistor. In a preferred embodiment, the resistor 6th at 25 degrees Celsius a specific resistance of 100 kiloohm or 68 kiloohm or 47 kiloohm or 33 kiloohm or 22 kiloohm or ten kiloohm.

The clamps 7th and 8th are advantageously implemented as compatible with the terminals of existing CdS-based arrangements. The clamps 7th and 8th preferably provide suitable plugs and / or suitable sockets that enable the terminals 7th and 8th easy to connect to (the terminals) of an existing combustion device. A feedback loop with the feedback elements 9 , 10 connects the output channel 3 of the differential amplifier 2 with its inverting (-) input channel. The feedback element 9 is preferably a resistor such as an ohmic resistor. The feedback element 10 is preferably a capacitor.

The signal U _out on the output channel 3 of the differential amplifier 2 is a function of the resistivity R _back of the element 9 : $$U_{aus}=f\left({\mathrm{R.}}_{\text{back}}\right)$$

In the ideal case, U _{out is} a first order polynomial of the specific resistance R _back .

U _out is also a function of the product R _back I _fot from the resistance R _back of the element 9 and photo current I _fot through the sensor 1 and / or the photodiode 1 : $$U_{\text{out}}=f\left({\mathrm{R.}}_{\text{back}}\cdot {\mathrm{I.}}_{\text{fot}}\right)$$

Furthermore, U _out can be a first order polynomial of the product R _back I _fot from resistance R _back from element 9 and photocurrent I _fot through the photodiode 1 be. In one embodiment, U _from also depends on the values R ₄ and R ₅ for the impedances 4th and 5 from: $$U_{\text{out}}=\left({\mathrm{R.}}_5+{\mathrm{R.}}_{\text{back}}\cdot \frac{{\mathrm{R.}}_5}{{\mathrm{R.}}_{\mathrm{4th}}}+{\mathrm{R.}}_{\text{back}}\right)\cdot {\mathrm{I.}}_{\text{fot}}$$

Since the photocurrent I _fot reaches small values with small incident light values, large values of R _{back are} required in order to generate significant changes in the output voltage U _out.

Appropriate values of the resistivity of the element 9 mitigate adverse influences due to offset voltages and / or bias currents, etc. The resistivity of the element 9 can for example reach 0.47 megaohms at 25 degrees Celsius. The resistivity of the element 9 According to another non-limiting example, it can reach 2 megaohms at 25 degrees Celsius. The resistivity of the element 9 can, in turn, according to a further non-limiting example, be 1 megohm at 25 degrees Celsius.

It is also provided that item 9 can be a potentiometer. In this way, the sensitivity of the in 1 circuit shown.

The feedback element 10 is advantageously a capacitor. The condenser 10 is parallel to the resistor 9 and / or impedance 9 switched. The condenser 10 contributes to the optimization of the dynamic properties of the system and / or inhibits the instability of the differential amplifier, for example 2 .

The choice of capacitor 10 depends on the input capacitance of the differential amplifier 2 from. The capacity of the element 10 also depends on the resistivity of the feedback resistor 9 and / or the feedback impedance 9 from. In addition, the choice of capacity 10 through the Capacity of the photodiode 1 and / or the sensor 1 influenced. In an exemplary embodiment, the capacitor is a 100 nanofarad capacitor or a twenty nanofarad capacitor or a 100 picofarad capacitor or a twenty picofarad capacitor.

Those skilled in the art understand that the characteristic of resistance 9 and / or the impedance 9 can also be capacitive to a certain extent.

According to a particular embodiment, the feedback elements are 9 and 10 implemented as a single resistive-capacitive element.

It is also provided that on the capacitor 10 can be dispensed with.

It is also provided on the feedback loop between the output channel 3 and the non-inverting (+) input channel of the differential amplifier 2 to renounce.

In this particular embodiment, the differential amplifier 2 effectively to a comparator. Accordingly, the differential amplifier generates 2 a high output signal (such as 3 volts, 2.5 volts, 1.2 volts, or 1.1 volts) that causes a photocurrent through the sensor 1 and / or the photodiode 1 causes.

The differential amplifier 2 produces a low output signal (essentially 0 volts) when there is no photocurrent through the diode 1 flows. The embodiment advantageously uses a positive feedback loop between the output channel 3 of the differential amplifier 2 and its non-inverting (+) input channel. The embodiment is ideally based on a sensor 1 and / or on a photodiode 1 that has (substantially) linear properties in the relevant operating range.

With reference to 2 is now a connection between the sensor arrangement and a supply and detection circuit 11 displayed. The supply and detection circuit 11 serves to supply the sensor arrangement with electrical current and / or with electrical energy. The supply and detection circuit 11 also serves to detect changes in the current and / or the output of the sensor arrangement due to the received light from the sensor 1 and / or the photodiode 1 capture. The sensor assembly sees a pair of wires 12 , 13 , for example a two-wire line, and a connector 14th in front.

It is provided that the connector 14th into a suitable connector and / or plug of the supply and detection circuit 11 is plugged in. The connector 14th thereby creates an electrical connection between the wires 12 , 13 and the supply and detection circuit 11 here. The wires 12 , 13 are ideally connected directly to the terminals 7th , 8th connected.

In one embodiment, the supply and detection circuit evaluates 11 Signals of the sensor arrangement from statistically. In particular, the supply and detection circuit 11 record several signals and average them appropriately. In a special embodiment, the supply and detection circuit 11 designed to evaluate signals of the sensor arrangement by oversampling.

In one embodiment, the supply and detection circuit evaluates 11 Signals from the sensor 1 statistically. In particular, the supply and detection circuit 11 record several signals and average them appropriately. In a special embodiment, the supply and detection circuit 11 formed, signals from the sensor 1 to detect and / or evaluate by oversampling.

In particular, the supply and detection circuit 11 , Signals from the sensor 1 on the terminals 7th , 8th to tap and to detect and / or evaluate by oversampling.

The sensor arrangement according to the present disclosure is advantageously arranged on a (printed) circuit board.

The specialist separates the paths for the supply voltages at the terminals 7th , 8th and / or for inverting (-) and / or non-inverting (+) input channels and / or for output channels 3 . Parasitic currents are therefore suppressed or prevented. It is envisaged that suitable protective tracks on the circuit board, for example on the printed circuit board, can be arranged between these paths. This further reduces parasitic effects.

It is provided that the connector 14th also includes an ammeter and / or an analog-to-digital converter and / or a processing unit and / or a radio frequency module. The radio frequency module can be connected to an antenna. Ideally the connector comprises 14th also an energy supply such as an electric battery and / or an energy conversion circuit. In this way, relevant components are supplied with electricity.

The ammeter is in series with one of the wires 12 , 13 and records a current value that corresponds to the current through at least one of the wires 12 , 13 corresponds. The analog-digital Converter receives the analog current value from the ammeter and converts the value into a digital representation. The processing unit generates a message from the digital representation for transmission via a computer network.

The digital message is then sent to the radio frequency module. The radio frequency module converts the message into a radio frequency signal that is relayed to the antenna. In one embodiment, the analog / digital converter and / or the radio frequency module is integrated into the processing unit.

It can be provided that this message is divided into several messages. The latter step offers advantages in terms of redundancy and / or immunity to interference. The radio frequency module can enable unidirectional or bidirectional wireless communication. The data transmission can be directional or non-directional. According to one aspect, the radio frequency module uses a modulation process that takes into account the properties of the air interface between the receiver and the transmitter. The factors that influence the choice of a particular modulation process include, but are not limited to, range, interference immunity, bit rate, channel bandwidth, properties of the channel, etc. According to one aspect, the modulation process can change over time depending on the properties of the Change communication channel. The modulation process thus adapts continuously to achieve optimal performance. According to another aspect, the bandwidth of a particular channel is divided into several frequency bands. Ideally, each frequency band uses its own modulation process that corresponds to the characteristics of the frequency band. Each frequency band advantageously carries a portion of the data traffic that depends on the capacity of the frequency band for data transmission. According to a further aspect, a digital modulation process is used to reduce and / or mitigate interference. A digital modulation process uses a digital signal to modulate an analog carrier. As a non-limiting example, digital modulation processes may be based on techniques such as phase shift keying, continuous phase modulation, and / or quadrature amplitude modulation.

With reference to 3 is now a bridge rectifier 15th shown. The bridge rectifier 15th supplies currents via its load connections 18th , 19th to the diode array. At the bridge rectifier 15th are the load connections 18th , 19th with the clamps 7th , 8th connected to the diode array.

The bridge rectifier 15th also provides a pair of supply terminals 16 , 17th ready. These supply terminals are ideally with a wire pair 12 , 13 connected, which supplies the entire arrangement with power.

The arrangement out 3 offers advantages in terms of immunity against polarity reversal and / or against wiring errors. The sensor assembly will not be damaged even if there is tension between the wires 12 , 13 is incorrectly reversed.

According to one aspect, electrical components of the circuits disclosed here, such as resistors, capacitors and protective tracks, are arranged on a printed circuit board using additive manufacturing technology. These resistors and capacitors can in particular be arranged using a three-dimensional additive manufacturing technique. The person skilled in the art selects suitable materials as well as suitable parameters such as the temperature when printing electrical components. In addition, necessary mechanical elements such as sockets for integrated circuits, in particular sockets for operational amplifiers, can be arranged via additive manufacturing. The person skilled in the art selects suitable materials and suitable parameters such as rigidity and / or glass transition temperature when printing mechanical elements. Additive manufacturing techniques offer advantages in terms of low costs even with small quantities.

The previous state of the art was to detect hydrogen flames with photosensitive UV tubes. UV tubes, or in other words UV cells, have a maximum spectral sensitivity in a wavelength range of 210 nanometers. Meanwhile, a hydrogen flame emits light in the spectral range from 260 nanometers to 330 nanometers with a maximum at 313 nanometers. How to get out 4th detects, covers the measuring range 21st the UV tube the area 20th very little of the emission from a hydrogen flame.

However, UV tubes are very sensitive to light intensity. Therefore, the low spectral sensitivity in the area of the emitted hydrogen flame is still sufficient to detect a hydrogen flame. UV tubes have the disadvantage that aging effects occur due to changes in the gas composition of the tube and the electrode surface. Such aging effects limit the service life of a UV tube. In addition, UV tubes are expensive compared to UV semiconductor sensors.

UV-sensitive semiconductors can be used particularly well for pure hydrogen as a fuel gas when the sensitive wavelength range is in the emission range of hydrogen flames.

Silicon photodiodes normally have a maximum spectral sensitivity in the range from visible red light to the infrared range. 5 serves to illustrate the spectral sensitivity of silicon photodiodes. The maximum of the spectral sensitivity is around 950 nanometers. At first, silicon photodiodes therefore seem to be unsuitable, since parasitic light such as sunlight or artificial room light can simulate a flame. This hinders or prevents the reliable detection of a flame failure.

However, there is the possibility of parasitic wavelength ranges in front of the sensor by means of one or more optical filters 1 and / or the photodiode 1 to filter out. For example, two optical filters connected in series can be used. The first filter is a mechanically built-in optical filter. The second filter is directly or essentially directly on the sensor 1 and / or the photodiode 1 applied as an interference filter. In one embodiment, the sensor comprises 1 the second filter. Both filters together effect a shielding of the silicon photodiode and a course according to 6th . The sensitive area is very well in the area of emissions from a hydrogen flame. The maximum of the spectral sensitivity from the sensor 1 with an optical filter is at a wavelength of 300 nanometers. The spectral sensitivity is due to the covering of the sensor 1 and / or the photodiode 1 in a very wide range of wavelengths except for the small UV residue. The low spectral intensity is mainly compensated by a very high amplification of the measurement signal.

Photodiodes based on SiC have the advantage that the spectral sensitivity without optical filters is directly above the emission range of a hydrogen flame. Illustrates the spectral sensitivity of the silicon carbide photodiode 7th . The maximum sensitivity here is 280 nanometers. In comparison to a silicon photodiode, the maximum sensitivity of the sensor and / or the photodiode is very much closer to the maximum of the emissions from a hydrogen flame. In the case of a silicon photodiode, only the residual sensitivity of the spectral range is effective. In addition, the dark current is significantly lower than that of a silicon photodiode. A hydrogen flame can therefore be measured very sensitively with a silicon carbide photodiode, as long as the amplification of the photocurrent is designed to be sufficiently strong.

Overall, the sensitivity depends not only on the spectral sensitivity but also on the light intensity that is emitted from the flame on the sensor 1 and / or on the photodiode 1 arrives. The sensitivity therefore depends on the geometric arrangement of the flame and sensor 1 and / or photodiode 1 from.

• einen Sensor (1) umfassend einen ersten und einen zweiten Sensoranschluss, wobei der Sensor (1) ausgebildet ist, in Reaktion auf das Empfangen einer ersten Menge an Licht von vorzugsweise 1.6·10^-3 Watt pro Quadratmeter einen Signalversatz zwischen seinen Sensoranschlüssen zu erzeugen, und in Reaktion auf das Empfangen einer zweiten Menge an Licht von weniger als 1.6·10^-3 Watt pro Quadratmeter gleiche Signale an seinen Anschlüssen zu erzeugen;
• einen Differenzverstärker (2), der einen ersten (7) und einen zweiten (8) Versorgungsanschluss, einen Ausgangskanal (3), einen invertierenden (-) und einen nicht invertierenden (+) Eingangskanal umfasst;
• ein Lastelement (6), das den Ausgangskanal (3) mit einem der Versorgungsanschlüsse (7, 8) verbindet;
• wobei der erste Sensoranschluss mit dem invertierenden (-) Eingangskanal elektrisch verbunden ist und der zweite Sensoranschluss mit dem nicht invertierenden (+) Eingangskanal elektrisch verbunden ist, so dass der Sensor (1) ausgebildet ist, Signale an die Eingangskanäle (-, +) anzulegen;
• wobei der Differenzverstärker (2) ausgebildet ist, in Reaktion auf den Signalversatz, welcher zwischen dem invertierenden (-) und dem nicht invertierenden (+) Eingangskanal angelegt wird, einen Strom an seinem Ausgangskanal (3) zu erzeugen, und das Lastelement (6) ausgebildet ist, eine erste Leistungsmenge in Abhängigkeit von dem am Ausgangskanal (3) erzeugten Strom abzuführen;
• wobei der Differenzverstärker (2) ausgebildet ist, in Reaktion darauf, dass der Signalversatz zwischen dem invertierenden (-) und dem nicht invertierenden (+) Eingangskanal angelegt wird, einen Laststrom aus den Versorgungsanschlüssen (7, 8) zu ziehen;
• wobei der Differenzverstärker (2) ausgebildet ist, in Reaktion darauf, dass gleiche Signale durch den Sensor (1) an die Eingangskanäle (-, +) angelegt werden, einen Ruhestrom aus den Versorgungsanschlüssen (7, 8) zu ziehen;
• wobei der Laststrom den Ruhestrom um wenigstens fünfzig Prozent übersteigt und der Ruhestrom kleiner als fünfzehn Mikroampere ist; und
• wobei der Sensor (1) ausgewählt ist aus
  • einem Sensor ausschliesslich bestehend aus einer Siliziumcarbid-Fotodiode und dem ersten und dem zweiten Sensoranschluss oder
  • einem Sensor umfassend eine Silizium-Fotodiode und den ersten und den zweiten Sensoranschluss und mindestens ein optisches Filter.

In other words, the present disclosure teaches a sensor arrangement for a combustion device, the sensor arrangement comprising:

• a sensor ( 1 ) comprising a first and a second sensor connection, where the sensor ( 1 Is formed) to create a signal offset between its sensor terminals in response to receiving a first quantity of light of preferably 1.6 × 10 ^-3 Watt per square meter, and in response to receiving a second quantity of light of less than 1.6 x 10 ^{- 3} watts per square meter to generate the same signals at its connections;
• a differential amplifier ( 2 ), which has a first (7) and a second (8) supply connection, an output channel ( 3 ), an inverting (-) and a non-inverting (+) input channel;
• a load element ( 6th ), which is the output channel ( 3 ) with one of the supply connections ( 7th , 8th ) connects;
• wherein the first sensor connection is electrically connected to the inverting (-) input channel and the second sensor connection is electrically connected to the non-inverting (+) input channel, so that the sensor ( 1 ) is designed to apply signals to the input channels (-, +);
• where the differential amplifier ( 2 ) is formed, in response to the signal offset which is applied between the inverting (-) and the non-inverting (+) input channel, a current at its output channel ( 3 ) and the load element ( 6th ) is designed, a first amount of power depending on the output channel ( 3 ) dissipate generated electricity;
• where the differential amplifier ( 2 ) is configured, in response to the signal offset being applied between the inverting (-) and the non-inverting (+) input channel, a load current from the supply connections ( 7th , 8th ) to pull;
• where the differential amplifier ( 2 ), in response to the fact that identical signals are transmitted by the sensor ( 1 ) are applied to the input channels (-, +), a quiescent current from the supply connections ( 7th , 8th ) to pull;
• wherein the load current exceeds the quiescent current by at least fifty percent and the quiescent current is less than fifteen microamps; and
• where the sensor ( 1 ) is selected
  • a sensor consisting exclusively of a silicon carbide photodiode and the first and the second sensor connection or
  • a sensor comprising a silicon photodiode and the first and second sensor connections and at least one optical filter.

In one embodiment, the quiescent current is time-dependent. For example, the quiescent current can initially be less than two microamps, after five seconds it can be less than five microamps and after ten seconds it may be less than ten microamps. According to a further example, the quiescent current can initially be less than five microamps, after five seconds it can be less than ten microamps and after ten seconds it can be less than fifteen microamps. Furthermore, the quiescent current can initially be less than five microamperes, after twenty seconds it can be less than ten microamperes and after sixty seconds it can be less than fifteen microamperes.

Furthermore, it can be provided that the load current exceeds the quiescent current by a time-dependent percentage. The load current can initially exceed the quiescent current by at least fifty percent. After five seconds, the load current exceeds the quiescent current by at least one hundred percent. After ten seconds, the load current exceeds the quiescent current by two hundred percent. In another example, the load current can exceed the quiescent current by at least one hundred percent after twenty seconds and by at least two hundred percent after sixty seconds.

Time-dependent quiescent currents and / or time-dependent load currents cause saturation effects in the sensor 1 , especially in a diode, bill.

In a further embodiment, the quiescent current is power-dependent. For example, the quiescent current can initially be less than two microamps, when twenty percent of the output of the combustion device is reached, it can be less than five microamperes, and when fifty percent of the output of the combustion device is reached, it can be less than ten microamperes. According to a further example, the quiescent current can initially be less than five microamps, when twenty percent of the combustion device's output is reached, less than ten microamperes, and when fifty percent of the combustion device's output is reached, less than fifteen microamperes.

Furthermore, it can be provided that the load current exceeds the quiescent current by a power-dependent percentage. The load current can initially exceed the quiescent current by at least fifty percent. After reaching twenty percent of the power of the combustion device, the load current exceeds the quiescent current by at least one hundred percent. After reaching fifty percent of the power of the combustion device, the load current exceeds the quiescent current by two hundred percent.

Power-dependent quiescent currents and / or power-dependent load currents cause saturation effects in the sensor 1 , especially in a diode, bill.

Ideally, the sensor ( 1 ) is designed to generate different signals at its terminals in response to receiving a first amount of light of 1.6 · 10 ^{-3 watts per square meter.} In one embodiment, the sensor is ( 1 ) is designed to generate different signals at its terminals in response to receiving a first amount of light of 1.5 · 10 ^{-3 watts per square meter.} In a special embodiment, the sensor ( 1 ) is designed to generate different signals at its terminals in response to receiving a first amount of light of 7.5 · 10 ^{-4 watts per square meter.}

Ideally, a signal offset is a positive or negative difference between signals. In particular, a signal offset between the sensor connections ( 1 ) a positive or negative difference between signals that are sent to the sensor ( 1 ) issue. A signal offset between the sensor connections ( 1 ) a positive or negative difference in electrical voltages which are present at the sensor connections ( 1 ) issue.

The first sensor connection is preferably galvanically connected to the inverting (-) input channel and the second sensor connection is galvanically connected to the non-inverting (+) input channel, so that the sensor ( 1 ) is designed to apply signals to the input channels (-, +).

Ideally, the differential amplifier ( 2 ), in response to the signal offset applied between the inverting (-) and the non-inverting (+) input channel, a current at its output channel ( 3 ) and the load element ( 6th ) is designed to generate a first amount of power depending on the output channel ( 3 ) dissipate generated electricity exclusively in the form of heat.

The present disclosure further teaches one of the preceding sensor devices, wherein the sensor ( 1 ) a silicon photodiode and a comprises a first optical filter and a second optical filter; and
wherein the second optical filter is attached directly to the silicon photodiode.

The first optical filter is different from the second optical filter.

The present disclosure also teaches one of the aforementioned sensor arrangements with the inclusion of two filters, the first optical filter and the second optical filter being arranged optically in series; and
wherein the second optical filter comprises an interference filter.

The present disclosure also teaches one of the aforementioned sensor arrangements with the inclusion of two filters, the first optical filter and the second optical filter being arranged optically in series; and
wherein the second optical filter is an interference filter.

The present disclosure also teaches one of the aforementioned sensor arrangements, wherein the sensor ( 1 ) comprises a silicon carbide photodiode; and
the silicon carbide photodiode has a spectral sensitivity in a wavelength range between 250 nanometers and 400 nanometers.

The present disclosure also teaches one of the aforementioned sensor arrangements, wherein the sensor ( 1 ) is a silicon carbide photodiode; and
the silicon carbide photodiode has a maximum spectral sensitivity in a wavelength range between 250 nanometers and 400 nanometers.

The present disclosure also teaches one of the aforementioned sensor arrangements, the sensor arrangement additionally having a feedback resistor ( 9 ) which includes the output channel ( 3 ) with the inverting (-) input channel of the differential amplifier ( 2 ) connects.

The present disclosure also teaches one of the aforementioned sensor arrangements, wherein the sensor arrangement additionally includes a feedback capacitor ( 10 ) which includes the output channel ( 3 ) with the inverting (-) input channel of the differential amplifier ( 2 ) connects.

The present disclosure also teaches one of the aforementioned sensor arrangements with the inclusion of a feedback capacitor ( 10 ), where the sensor ( 1 ) has a sensor capacitance between the sensor connections;
where the feedback capacitor ( 10 ) has a feedback capacitance; and
where the feedback capacitance is formed in connection with the sensor capacitance, an instability of the differential amplifier ( 2 ) to suppress.

The present disclosure also teaches one of the aforementioned sensor arrangements with the inclusion of a feedback capacitor ( 10 ), where the sensor ( 1 ) has a sensor capacitance between the sensor connections;
where the feedback capacitor ( 10 ) has a feedback capacitance; and
where the feedback capacitance is formed in connection with the sensor capacitance, an instability of the differential amplifier ( 2 ) to prevent.

The present disclosure also teaches one of the aforementioned sensor arrangements, the sensor arrangement additionally having a first ground impedance ( 4th ) that connects the inverting (-) input channel to one of the supply connections ( 7th , 8th ) connects.

The present disclosure also teaches one of the aforementioned sensor arrangements, the sensor arrangement additionally having a first ground impedance ( 4th ) that connects the inverting (-) input channel to one of the supply connections ( 7th , 8th ) galvanically connects.

The present disclosure also teaches one of the aforementioned sensor arrangements with the inclusion of a first earth impedance ( 4th ), whereby the sensor arrangement additionally has a second earth impedance ( 5 ) that connects the non-inverting (+) input channel to one of the supply connections ( 7th , 8th ) connects; and
where the first earth impedance ( 4th ) and the second earth impedance ( 5 ) both have a connection to the same supply connection ( 7th , 8th ) produce.

The present disclosure also teaches one of the aforementioned sensor arrangements with the inclusion of a first earth impedance ( 4th ), whereby the sensor arrangement additionally has a second earth impedance ( 5 ) that connects the non-inverting (+) input channel to one of the supply connections ( 7th , 8th ) galvanically connects; and
where the first earth impedance ( 4th ) and the second earth impedance ( 5 ) both have a connection to one and the same supply connection ( 7th , 8th ) produce.

The first earth impedance ( 4th ) is different from the second earth impedance ( 5 ).

The present disclosure also teaches one of the aforementioned sensor arrangements with the inclusion of two earth impedances ( 4th , 5 ), where the first earth impedance ( 4th ) a first Impedance value and the second earth impedance ( 5 ) has a second impedance value; and
wherein the second impedance value exceeds the first impedance value by at least a factor of ten.

• wobei der Laststrom ein elektrischer Strom ist;
• wobei der Ruhestrom ein elektrischer Strom ist;
• wobei die erste Leitung (12) eine erste elektrische Verbindung zu dem ersten Versorgungsanschluss (7) herstellt und die zweite Leitung (13) eine zweite elektrische Verbindung zu dem zweiten Versorgungsanschluss (8) herstellt;
• wobei das Leitungspaar (12, 13) zusätzlich einen Thermistor mit positivem Temperaturkoeffizienten umfasst; und
• wobei der positive Temperaturkoeffizient so bemessen ist, dass er im Falle eines Kurzschlusses in der Sensoranordnung (1) einen elektrischen Strom durch das Leitungspaar (12, 13) auf weniger als zwei Ampere begrenzt.

The present disclosure further teaches one of the aforementioned sensor arrangements, wherein the sensor arrangement comprises a line pair with a first line ( 12 ) and with a second line ( 13 ) includes;

• wherein the load current is an electrical current;
• wherein the quiescent current is an electrical current;
• where the first line ( 12 ) a first electrical connection to the first supply connection ( 7th ) and the second line ( 13 ) a second electrical connection to the second supply connection ( 8th ) manufactures;
• where the line pair ( 12 , 13 ) additionally comprises a thermistor with a positive temperature coefficient; and
• where the positive temperature coefficient is dimensioned so that in the event of a short circuit in the sensor arrangement ( 1 ) an electric current through the pair of wires ( 12 , 13 ) limited to less than two amps.

• wobei der Laststrom ein elektrischer Strom ist;
• wobei der Ruhestrom ein elektrischer Strom ist;
• wobei die erste Leitung (12) eine erste galvanische Verbindung zu dem ersten Versorgungsanschluss (7) herstellt und die zweite Leitung (13) eine zweite galvanische Verbindung zu dem zweiten Versorgungsanschluss (8) herstellt;
• wobei das Leitungspaar (12, 13) zusätzlich einen Thermistor mit positivem Temperaturkoeffizienten umfasst; und
• wobei der positive Temperaturkoeffizient so bemessen ist, dass er im Falle eines Kurzschlusses in der Sensoranordnung (1) einen elektrischen Strom durch das Leitungspaar (12, 13) auf weniger als zwei Ampere begrenzt.

The present disclosure also teaches one of the aforementioned sensor arrangements, wherein the sensor arrangement comprises a line pair with a first line ( 12 ) and with a second line ( 13 ) includes;

• wherein the load current is an electrical current;
• wherein the quiescent current is an electrical current;
• where the first line ( 12 ) a first galvanic connection to the first supply connection ( 7th ) and the second line ( 13 ) a second galvanic connection to the second supply connection ( 8th ) manufactures;
• where the line pair ( 12 , 13 ) additionally comprises a thermistor with a positive temperature coefficient; and
• where the positive temperature coefficient is dimensioned so that in the event of a short circuit in the sensor arrangement ( 1 ) an electric current through the pair of wires ( 12 , 13 ) limited to less than two amps.

Preferably, the positive temperature coefficient limits in the event of a short circuit in the sensor arrangement ( 1 ) an electric current through the pair of wires ( 12 , 13 ) to less than an ampere. In particular, the positive temperature coefficient in the event of a short circuit in the sensor arrangement ( 1 ) an electric current through the pair of wires ( 12 , 13 ) to less than half an ampere. The limitation of short-circuit currents serves to prevent damage to the sensor arrangement and / or to a supply and detection circuit ( 11 ) due to excessive currents.

• wobei der Laststrom ein elektrischer Strom ist;
• wobei der Ruhestrom ein elektrischer Strom ist;
• wobei die erste Leitung (12) eine erste elektrische Verbindung zu dem ersten Versorgungsanschluss (7) herstellt und die zweite Leitung (13) eine zweite elektrische Verbindung zu dem zweiten Versorgungsanschluss (8) herstellt; und
• wobei das Leitungspaar (12, 13) ausgebildet ist, ausschliesslich die Sensoranordnung mit elektrischen Strömen und/oder mit Datensignalen zu versorgen.

The present disclosure also teaches one of the aforementioned sensor arrangements, the sensor arrangement having a line pair with a first line ( 12 ) and with a second line ( 13 ) includes;

• wherein the load current is an electrical current;
• wherein the quiescent current is an electrical current;
• where the first line ( 12 ) a first electrical connection to the first supply connection ( 7th ) and the second line ( 13 ) a second electrical connection to the second supply connection ( 8th ) manufactures; and
• where the line pair ( 12 , 13 ) is designed to exclusively supply the sensor arrangement with electrical currents and / or with data signals.

The present disclosure also teaches one of the aforementioned sensor arrangements including a line pair with a first line ( 12 ) and with a second line ( 13 ), where the pair of lines has a connector ( 14th ) to connect the first line ( 12 ) and the second line ( 13 ) with a supply and
Detection circuit ( 11 ) provides;
where the connector ( 14th ) is the only connector of the sensor arrangement which is designed to connect the first line ( 12 ) and the second line ( 13 ) with the supply and detection circuit ( 11 ) connect to.

The present disclosure also teaches one of the aforementioned sensor arrangements including a line pair with a first line ( 12 ) and with a second line ( 13 ), where the pair of lines has a connector ( 14th ) for galvanic connection of the first line ( 12 ) and the second line ( 13 ) with a supply and detection circuit ( 11 ) provides; and
where the connector ( 14th ) is the only connector of the sensor arrangement which is designed to connect the first line ( 12 ) and the second line ( 13 ) galvanically with the supply and detection circuit ( 11 ) connect to.

• wobei der Laststrom ein elektrischer Strom ist;
• wobei der Ruhestrom ein elektrischer Strom ist,
  • wobei die erste Leitung (12) und die zweite Leitung (13) eine Verbindung zu den Versorgungsanschlüssen (16, 17) des Brückengleichrichters (15) herstellen;
  • wobei der Brückengleichrichter (15) ausgebildet ist, einen elektrischen Wechselstrom, der zwischen seinen Versorgungsanschlüssen (16, 17) angelegt wird, in einen elektrischen Gleichstrom zwischen seinen Lastanschlüssen (18, 19) umzuwandeln;
  • wobei der erste Versorgungsanschluss (7) und der zweite Versorgungsanschluss (8) je eine galvanische Verbindung zu den Lastanschlüssen (18, 19) des Brückengleichrichters (15) herstellen; und
  • wobei das Leitungspaar ausgebildet ist, ausschliesslich die Sensoranordnung mit elektrischen Strömen und/oder mit Datensignalen zu versorgen.

The present disclosure also teaches one of the aforementioned sensor arrangements, the sensor arrangement additionally having a bridge rectifier ( 15th ) with supply connections ( 16 , 17th ) and with load connections ( 18th , 19th ) and a Line pair with a first line ( 12 ) and with a second line ( 13 ) includes;

• wherein the load current is an electrical current;
• where the quiescent current is an electric current,
  • where the first line ( 12 ) and the second line ( 13 ) a connection to the supply connections ( 16 , 17th ) of the bridge rectifier ( 15th ) produce;
  • where the bridge rectifier ( 15th ) is formed, an electrical alternating current that flows between its supply connections ( 16 , 17th ) is applied into a direct electrical current between its load terminals ( 18th , 19th ) to convert;
  • where the first supply connection ( 7th ) and the second supply connection ( 8th ) one galvanic connection each to the load connections ( 18th , 19th ) of the bridge rectifier ( 15th ) produce; and
  • wherein the line pair is designed to exclusively supply the sensor arrangement with electrical currents and / or with data signals.

The present disclosure also teaches one of the aforementioned sensor arrangements, wherein the photodiode of the sensor ( 1 ) has an anode and a cathode; and
wherein the first sensor connection connects to the cathode of the photodiode and the second sensor connection connects to the anode of the photodiode.

The present disclosure also teaches one of the aforementioned sensor arrangements, wherein the photodiode of the sensor ( 1 ) has an anode and a cathode; and
wherein the first sensor connection produces a galvanic connection to the cathode of the photodiode and the second sensor connection produces a galvanic connection to the anode of the photodiode.

The present disclosure also teaches a combustion device comprising one of the preceding sensor arrangements.

The present disclosure further teaches a boiler device comprising any of the foregoing sensor arrangements.

The present disclosure further teaches a boiler device comprising a gas burner and one of the foregoing sensor arrangements.

The present disclosure further teaches a boiler apparatus comprising an oil burner and one of the foregoing sensor arrangements.

The above relates to individual embodiments of the disclosure. Various changes to the embodiments can be made without departing from the underlying idea and without departing from the scope of this disclosure. The subject matter of the present disclosure is defined by its claims. A wide variety of changes can be made without departing from the scope of protection of the following claims.

List of reference symbols

1

sensor

2

Differential amplifier

3

Output channel

4th

Impedance

5

Impedance

6th

Impedance

7th

Clamp

8th

Clamp

9

Impedance

10

capacitor

11

Supply and detection circuit

12, 13

Wires

14th

Interconnects

15th

Bridge rectifier

16

Supply terminal

17th

Supply terminal

18th

Load connection

19th

Load connection

20th

Emissions from a hydrogen flame

21st

Measuring range of a UV tube

22nd

Measuring range of a silicon photodiode

23

Measuring range of a (multiple) filtered silicon photodiode

24

Measuring range of a silicon carbide photodiode.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• CN 101221071 B [0005]
• EP 0942232 B1 [0006, 0008]
• DE 2654881 A1 [0009]
• EP 3339736 B1 [0010]

Claims (15)

A sensor arrangement for a combustion device, the sensor arrangement comprising: a sensor (1) comprising a first and a second sensor connection, the sensor (1) being configured in response to receiving a first amount of light of preferably 1.6 · 10 ^-3 watts per Square meter generate a signal offset between its sensor terminals and, in response to receiving a second amount of light less than 1.6 x 10 ^-3 watts per square meter, generate equal signals at its terminals; a differential amplifier (2) which comprises a first (7) and a second (8) supply connection, an output channel (3), an inverting (-) and a non-inverting (+) input channel; a load element (6) which connects the output channel (3) to one of the supply connections (7, 8); wherein the first sensor connection is electrically connected to the inverting (-) input channel and the second sensor connection is electrically connected to the non-inverting (+) input channel, so that the sensor (1) is designed to apply signals to the input channels (-, +) ; wherein the differential amplifier (2) is designed to generate a current at its output channel (3) in response to the signal offset which is applied between the inverting (-) and the non-inverting (+) input channel, and the load element (6) is designed to dissipate a first amount of power depending on the current generated at the output channel (3); wherein the differential amplifier (2) is configured to draw a load current from the supply connections (7, 8) in response to the signal offset being applied between the inverting (-) and the non-inverting (+) input channel; wherein the differential amplifier (2) is designed to draw a quiescent current from the supply connections (7, 8) in response to the fact that identical signals are applied by the sensor (1) to the input channels (-, +); wherein the load current exceeds the quiescent current by at least fifty percent and the quiescent current is less than fifteen microamps; and wherein the sensor (1) is selected from a sensor consisting exclusively of a silicon carbide photodiode and the first and second sensor connections or a sensor comprising a silicon photodiode and the first and second sensor connections and at least one optical filter. The sensor arrangement according to Claim 1 wherein the sensor (1) comprises a silicon photodiode and a first optical filter and a second optical filter; and wherein the second optical filter is attached directly to the silicon photodiode. The sensor arrangement according to Claim 2 wherein the first optical filter and the second optical filter are optically arranged in series; and wherein the second optical filter comprises an interference filter. The sensor arrangement according to Claim 1 wherein the sensor (1) comprises a silicon carbide photodiode; and the silicon carbide photodiode has a spectral sensitivity in a wavelength range between 250 nanometers and 400 nanometers. The sensor arrangement according to one of the Claims 1 to 4th wherein the sensor arrangement additionally comprises a feedback resistor (9) which connects the output channel (3) to the inverting (-) input channel of the differential amplifier (2). The sensor arrangement according to one of the Claims 1 to 5 , wherein the sensor arrangement additionally comprises a feedback capacitor (10) which connects the output channel (3) to the inverting (-) input channel of the differential amplifier (2). The sensor arrangement according to Claim 6 wherein the sensor (1) has a sensor capacitance between the sensor connections; wherein the feedback capacitor (10) has a feedback capacitance; and wherein the feedback capacitance is designed in connection with the sensor capacitance to suppress instability of the differential amplifier (2). The sensor arrangement according to one of the Claims 1 to 7th , wherein the sensor arrangement additionally comprises a first ground impedance (4) which connects the inverting (-) input channel to one of the supply connections (7, 8). The sensor arrangement according to Claim 8 , wherein the sensor arrangement additionally comprises a second ground impedance (5) which connects the non-inverting (+) input channel to one of the supply connections (7, 8); and wherein the first earth impedance (4) and the second earth impedance (5) both establish a connection to the same supply connection (7, 8). The sensor arrangement according to Claim 9 wherein the first earth impedance (4) has a first impedance value and the second earth impedance (5) has a second impedance value; and wherein the second impedance value exceeds the first impedance value by at least a factor of ten. The sensor arrangement according to one of the Claims 1 to 10 wherein the sensor arrangement comprises a line pair with a first line (12) and with a second line (13); wherein the load current is an electrical current; wherein the quiescent current is an electrical current; wherein the first line (12) produces a first electrical connection to the first supply connection (7) and the second line (13) produces a second electrical connection to the second supply connection (8); and wherein the pair of lines (12, 13) additionally comprises a thermistor with a positive temperature coefficient; and wherein the positive temperature coefficient is dimensioned such that it limits an electrical current through the line pair (12, 13) to less than two amperes in the event of a short circuit in the sensor arrangement (1). The sensor arrangement according to Claim 11 the pair of lines providing a connector (14) for connecting the first line (12) and the second line (13) to a supply and detection circuit (11); wherein the connector (14) is the only connector of the sensor arrangement which is designed to connect the first line (12) and the second line (13) to the supply and detection circuit (11). The sensor arrangement according to one of the Claims 1 to 10 , wherein the supply and detection circuit (11) is designed to detect signals from the sensor (1) by oversampling. The sensor arrangement according to one of the Claims 1 to 13 wherein the photodiode of the sensor (1) has an anode and a cathode; and wherein the first sensor connection connects to the cathode of the photodiode and the second sensor connection connects to the anode of the photodiode. Combustion device comprising a sensor arrangement according to one of the Claims 1 to 14th .

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