Low-noise emitter device, control loop, and method for operating the control loop

Abstract

The invention relates to an emitter device (1) comprising: a plurality of emitters (5); a plurality of current drivers (6); and a plurality of TEC systems (4), wherein each individual emitter (5) is assigned at least one of the current drivers (6) and one of the TEC systems (4) and the plurality of TEC systems (4) are designed and configured to control the temperature of at least one of the emitters (5) and of at least one of the current drivers (6).

Description

[0001] Low-noise emitter device, control loop and method for operating the control loop

[0002] Description

[0003] The invention relates to an emitter device according to claim 1, a gyroscope according to claim 13, a control circuit according to claim 14 and a method for operating the control circuit according to claim 15.

[0004] In known emitter devices, a setpoint for an emitter current was adjusted by a resistor. Changing the setpoint was achieved by manually unsoldering the original resistor and manually inserting a different resistor. In other known emitter devices, a temperature setpoint was achieved by controlled switching on and off of the emitter device, resulting in heating in the on state and cooling in the off state. Other emitter devices used a trimming resistor, or potentiometer, to adjust the temperature setpoint.

[0005] A disadvantage of the aforementioned prior art is that the known emitter devices are susceptible to interference.

[0006] Based on this, the present invention is based on the object of providing an improved emitter device. A further object of the invention is to provide an improved gyroscope with such an emitter device. Furthermore, the invention is based on the object of providing an improved control loop for such an emitter device and a method for operating the control loop. This object is achieved by the present invention. The invention is defined by the subject matter with the features of the independent claims directed thereto. Advantageous embodiments and further developments of the invention are the subject of subclaims and the following description.

[0007] The emitter device according to the invention and preferred developments thereof are preferably designed and provided for use in the gyroscope according to the invention, the control circuit according to the invention and the method according to the invention, as well as in preferred developments thereof.

[0008] All features of the subject matter described herein and also of the claimed subject matter are usable both in isolation and in combination with one another, are compatible with one another, and are intended and usable for further development of one another, and are hereby disclosed as such, unless a logical contradiction arises. The mere fact that certain features are recited in different claims does not mean that a combination of these features is not contemplated and advantageous.

[0009] In the following, any reference to an object or feature (including the indefinite articles "a" and "an" and the definite articles "the"), two objects or two features, or any other number of objects or features, unless expressly stated otherwise or a logical contradiction arises, is to be understood as meaning that the presence of further such objects and features is not excluded from the invention, but is also encompassed by the invention. The words "comprising," "having," and "with" do not exclude further objects, features, elements, or steps. The reference numerals in the claims are not to be understood as limiting but merely serve to improve the readability of the claims. According to a first aspect of the invention, the emitter device has a plurality of emitters for emitting light.The emitter device further comprises a plurality of current drivers. The current drivers are designed and configured to supply electrical current to at least one of the emitters. The emitter device also comprises a plurality of TEC systems. The TEC systems are designed and configured to regulate the temperature of at least one of the emitters, and in particular of at least one of the current drivers. In the emitter device, at least one of the current drivers and one of the TEC systems is assigned to each individual emitter.

[0010] The emitter is preferably designed to emit light. In particular, the emitter emits light beams when supplied with an electric current. The emitter is preferably a laser diode. The emitter is preferably an LED diode. The plurality of emitters comprises, in particular, a first emitter and a second emitter. The emitters of the plurality of emitters are preferably identical in design.

[0011] The "current driver" preferably drives electrical current through the emitter. The current driver is preferably a laser diode current driver. The current driver is preferably an LDO current driver. The plurality of current drivers comprises, in particular, a first current driver and a second current driver. The current drivers of the plurality of current drivers are preferably identical in design.

[0012] The "TEC system" comprises, in particular, a TEC controller and a TEC element. The TEC element is preferably a Peltier element. The TEC system preferably regulates the temperature by comparing a measured temperature and a set target temperature. Preferably, if there is a predetermined deviation between these temperatures, the TEC controller provides an adjusted current to the TEC element. The plurality of TEC systems comprises, in particular, a first TEC system and a second TEC system. Preferably, the TEC systems of the plurality of TEC systems are structurally identical. According to a second aspect of the invention, the gyroscope comprises the emitter device. The "gyroscope" is preferably an atomic gyroscope, particularly preferably an atomic spin gyroscope. Preferably, the gyroscope has beam guiding optics, preferably with at least one mirror, through which the light beams are guided such that they intersect.

[0013] According to a third aspect of the invention, the control loop for the emitter device comprises a PID controller. Furthermore, the control loop includes a measuring resistor. The control loop also includes an instrumentation amplifier. In the control loop, at least one of the current drivers is arranged between the PID controller and the measuring resistor and is electrically connected thereto. Furthermore, the instrumentation amplifier is arranged between the PID controller and the measuring resistor and is electrically connected thereto.

[0014] The "PID controller" is preferably an integrator, particularly preferably an integrating amplifier. The PID controller is preferably an operational amplifier. The "measuring resistor" is preferably an ohmic resistor, particularly preferably a precision resistor.

[0015] The “instrument amplifier” is preferably a precise operational amplifier circuit with high-impedance inputs, typically 10 9 Q to 10 12Q. The “electrical connection” preferably establishes a permanent or detachable electrical contact between two elements and serves to conduct electric current.

[0016] According to a fourth aspect of the invention, the method for operating the control loop comprises the steps:

[0017] Providing the control loop;

[0018] Placing the measuring resistor between the current driver, the instrumentation amplifier and the laser diode;

[0019] Setting a voltage;

[0020] Generating a control signal, in particular at the PID controller; providing the control signal to the current driver; generating an emitter current at the current driver; applying the emitter current to the emitter; tapping the emitter current at the measuring resistor; providing a voltage to the instrumentation amplifier; determining the voltage, in particular an actual voltage, at the instrumentation amplifier;

[0021] Comparison of the determined voltage, in particular the actual voltage, with the set voltage, in particular a target voltage;

[0022] Adjustment of the control signal depending on the comparison.

[0023] Preferably, all steps of the method are carried out simultaneously. The "setting of the voltage" preferably involves specifying a target current by inputting a digital-analog converter voltage, which preferably corresponds to the target voltage. The emitter current is preferably generated by the current driver. The actual voltage is in particular a measurement voltage with an offset amount. The "tapping of the emitter current" preferably takes place by determining the measurement voltage with an offset amount at the measuring resistor. The "determination of the voltage" preferably corresponds to the provision of the actual voltage as a measurement voltage by the instrument amplifier. The control signal preferably corresponds to the integrator voltage. The control signal is preferably a control signal. The "adjustment of the control signal" is preferably carried out by the PID controller depending on the comparison.

[0024] The emitter device preferably comprises a plurality of circuit boards. Preferably, one of the emitters and the current drivers and TEC systems associated with it are each arranged on one of the circuit boards. Alternatively, the TEC controller is preferably arranged on the circuit board and the TEC element is arranged on the emitter. The plurality of circuit boards particularly comprises a first circuit board and a second circuit board. The "circuit board" is preferably a printed circuit. Preferably, at least one of the TEC systems is in thermal contact with at least one of the emitters. Preferably, at least one of the TEC systems is arranged in thermal contact with at least one of the current drivers.

[0025] Particularly preferably, the TEC system, particularly preferably the TEC element, most preferably only the TEC element, is arranged in thermal contact with exactly one of the emitters and preferably exactly one of the current drivers.

[0026] Preferably, the TEC systems are designed and configured to maintain the current drivers and / or the emitters at a constant temperature. The constant temperature preferably comprises a temperature deviation of 10 K to 0.01 K, particularly preferably of 5 K to 0.01 K, most preferably of 1 K to 0.01 K, and further preferably of 0.5 K to 0.01 K.

[0027] Preferably, the emitter device comprises a circuit board voltage source, which is particularly preferably arranged on or on the first circuit board or is comprised by the first circuit board.

[0028] The "circuit board voltage source" is preferably a linear regulator. The circuit board voltage source is particularly preferably an LT3045 linear regulator and / or an LT3094 linear regulator. The circuit board voltage source is preferably designed to convert a supply voltage provided by an external power supply.

[0029] Preferably, the circuit board voltage source is designed and configured to supply power to all TEC systems and / or all current drivers.

[0030] The emitter device preferably comprises a controller, which is particularly preferably arranged on or on the second circuit board or is encompassed by the second circuit board. The "controller" is preferably a microcontroller. Preferably, the circuit board voltage source is designed and configured to supply power to the controller. Preferably, the controller is arranged in conjunction with a serial interface and / or has a serial interface. The "serial interface" is in particular a "Universal Asynchronous Receiver Transmitter" interface, or UART interface for short. The "controller" preferably receives the temperature and current setpoints via the serial interface from a PC or a server.

[0031] Preferably, the controller is designed and configured to control all TEC systems, in particular their TEC controllers and / or all current drivers.

[0032] Preferably, the circuit boards are arranged in a common housing.

[0033] The "housing" preferably does not include a switching power supply. The ±12V for supplying the circuit board voltage source is preferably generated externally. In particular, the housing includes an interlock safety shutdown device, which preferably ensures that if a person enters the room in which the emitter device is operated, it is automatically switched off.

[0034] Tests have shown that all of the above-mentioned features and / or combinations of features result in several advantageous effects that are conducive to improving the emitter device, the gyroscope, the control loop, and the method for operating the control loop.

[0035] The first advantageous effect is that a particularly compact and miniaturized design can be realized, which can also be easily adapted to customer needs.

[0036] A second advantageous effect is that the multiple emitters allow for dual laser output, for example, with a probe laser and a pump laser. A third advantageous effect is that particularly low-noise light can be generated from the emitters, particularly through the preferential selection of low-noise current drivers and / or low-noise TEC systems and / or low-noise PCB voltage sources.

[0037] A fourth advantageous effect is that particularly high cooling efficiency can be achieved.

[0038] Advantageously, a temperature setpoint and / or a current setpoint can be defined and digitally entered by a user, for example, via a PC using the serial interface to the controller. This significantly simplifies and speeds up control. The faster control allows, for example, a sweep to be performed, in which a large number of values ​​of a parameter, such as the temperature setpoint and / or the current setpoint, are periodically cycled through within a defined range—that is, entered and controlled.

[0039] It is understood that the subject matter of the independent claims or the above description has similar and / or identical developments and embodiments. In a preferred embodiment, any combination of the dependent claims and / or the features described in the description with the respective independent claim is provided.

[0040] Further features and advantages of the invention will become apparent from the following description based on exemplary embodiments and the drawings. Although the invention is illustrated and disclosed in detail in the figures and the above description, these representations and descriptions are to be regarded as purely illustrative or exemplary and not restrictive. It is understood that the features mentioned above and those to be explained below can be used not only in the respective combination specified, but also in other combinations or on their own. Figure 1 shows an emitter device with two circuit boards;

[0041] Figure 2 shows a control loop;

[0042] Figure 3 shows a block diagram of the method for operating the control loop;

[0043] Figure 4 shows a first embodiment of a beam path with a mirror;

[0044] Figure 5 shows a second embodiment of a beam path with three mirrors.

[0045] Identical reference symbols used in the figures denote identical or at least equivalent elements. The terms "top," "bottom," "left," and "right," as well as direction-dependent information derived from them, such as "top," refer to the writing / reading direction of the figure designation "Fig." associated with a drawing, which is printed below the drawing on the drawing plane. The horizontal direction is parallel to the writing direction of "Fig.", and the vertical direction is perpendicular to the writing direction of "Fig." The writing direction is based on a horizontal, right-to-right script, i.e., primarily from left to right, as in Latin, English, French, and German, for example.

[0046] Figure 1 shows an emitter device 1 with a first circuit board 2a and a second circuit board 2b, which are arranged in a common housing 3. The first circuit board 2a comprises a first TEC system 4a, a first emitter 5a, and a first current driver 6a. In addition, the first circuit board 2a comprises a circuit board voltage source 7, which is electrically connected via a current conductor 8 to an external voltage source 9, preferably with a switch. The voltage source 9, preferably with a switch, is connected to a power connection 10, for example a 220 V power connection 10. The first emitter 5a is arranged in thermal contact 11a with the first TEC system 4a and can be supplied with electrical current by the first current driver 6a, in particular via a first DC conductor 12a. The second circuit board 2b comprises a second TEC system 4b, a second emitter 5b, a second current driver 6b and a controller 13.The controller 13 has a serial interface 14, which is designed as a UART interface 14. The UART interface 14 can be connected to an external PC and controlled via a UART signal. The second emitter 5b is arranged in thermal contact 11b with the second TEC system 4b and can be supplied with electrical current by the second current driver 6b, in particular via a second DC conductor 12b. During operation, the first emitter 6a emits a first light beam 15a, and the second emitter 6b emits a second light beam 15b. The light beams 15a, 15b are in particular laser beams.

[0047] The circuit board voltage source 7 is designed to supply power to all components arranged on the circuit boards 2a, 2b. For this purpose, the circuit board voltage source 7 is connected to the first TEC system 4a via a first current conductor 16a, to the second current driver 6b via a second current conductor 16b, to the controller 13 via a third current conductor 16c, to the second TEC system 4b via a fourth current conductor 16d, and to the first current driver 6a via a fifth current conductor 16e.

[0048] The controller 13 is connected to the first TEC system 4a via a first control signal path 17a, to the first current driver 6a via a second control signal path 17b, to the second TEC system 4b via a third control signal path 17c, and to the second current driver 6b via a fourth control signal path 6b. The controller 13 is also provided for switching the current drivers 6a, 6b on and off when the corresponding control is performed.

[0049] The emitters 5a, 5b are supplied with electrical current via the connected current drivers 6a, 6b, with the electrical current being provided with low noise by the circuit board voltage 7. The TEC systems 4a, 4b are arranged in thermal contact with the emitters 5a, 5b arranged on the same circuit boards 2a, 2b, and preferably with the current drivers 6a, 6b. This allows the TEC systems 4a, 4b to regulate the temperature of these components and maintain them within a preset constant temperature range. This precise temperature control allows the aforementioned components to operate with particularly low noise.

[0050] Figure 2 shows a control loop 18 with a PID controller 19, here an integrator 19, a current driver 6, a measuring resistor 20, and an instrumentation amplifier 21. The current driver 6 is arranged between the integrator 19 and the measuring resistor 20, and the instrumentation amplifier 21 is arranged between the integrator 19 and the measuring resistor 20. The measuring resistor 20 is designed to apply an emitter current 22 to the emitter 5a, 5b.

[0051] The integrator 19 is supplied with a digital-to-analog converter voltage 23 by a digital-to-analog converter (not shown here). The digital-to-analog converter voltage 23 corresponds to the output voltage of the digital-to-analog converter. During operation, an integrator voltage 24 is applied between the integrator 19 and the current driver 6. A current driver voltage 25 is applied between the current driver 6 and the measuring resistor 20. A measuring resistor voltage with an offset 26 is applied between the measuring resistor 20 and the instrumentation amplifier 21. A measuring resistor voltage 27 is applied between the instrumentation amplifier 21 and the integrator 19.

[0052] The control circuit 18 is designed such that, in the steady state, the measuring resistor voltage 27 is equal to the digital-analog converter voltage 23. The instrumentation amplifier 21 removes the offset of the measuring resistor voltage with offset 26, which offset is caused by the electronic components arranged after the measuring resistor 20, in particular a measuring resistor 20 (not shown here) and the emitter 5a, 5b (not shown here). The operational amplifier acts as an integrator 19 and compares the measuring resistor voltage 27 with the digital-analog converter voltage 23 of the digital-analog converter and increases or decreases the integrator voltage 24 accordingly to compensate for the offset. The current driver 6 can be considered a low-dropout series regulator (LDO) and thus a unified buffer.

[0053] Figure 3 shows a schematic block diagram of a method for operating the control loop 18 (shown in Figure 2). First, the control loop 18 and a measuring resistor 20 are provided. The measuring resistor 20 is then arranged between the current driver 6 and the instrumentation amplifier 21, and a voltage is set. In addition, a control signal 28 (corresponding to the integrator voltage 24) is generated by a control signal generator 29, in particular at the integrator 19. The control signal 28 is provided to the current driver 6. In addition, an emitter current 22 is generated at the current driver 6a, 6b, and the emitter 5a, 5b is supplied with the emitter current 22. The emitter current 22 is tapped at the measuring resistor 20. In addition, a voltage with an offset amount 30 (corresponding to the measuring voltage with an offset amount 26) is provided to the instrumentation amplifier 21.This specific voltage is compared with the set voltage of an input 31 (corresponding to the digital-to-analog converter voltage 23). The control signal 28 (corresponding to the integrator voltage 24) is adjusted depending on the comparison to compensate for a measured error 33 and to adjust the measured value 34 (corresponding to the measuring resistor voltage 27) to the set voltage 31.

[0054] Advantageously, a temperature setpoint and / or a current setpoint can be defined by a user and input to the controller 13 via the UART interface 14. The controller 13 transmits the temperature setpoint and / or the current setpoint to the TEC systems 4 and to the current drivers 6a, 6b via control signals 17 and via external digital-to-analog converters.

[0055] For implementation, software can be used on a PC to decode and process the received inputs and information. Figure 4 shows a first embodiment of a beam path of the two light beams 15a, 15b emitted from Figure 1. After the emitted light beams 15a, 15b have left the housing 3, they enter a beam guiding optics, where the second light beam 15b is reflected by a mirror 35. The mirror 35 is oriented at 45 degrees to the exit direction of the second light beam 15b and, after striking the mirror 35, reflects the second light beam 15b at a 90° angle, as shown in Figure 4. The first light beam 15a passes through the beam guiding optics undeflected and therefore retains its original exit direction. After the 90-degree deflection of the second light beam 15b, it crosses the first light beam 15a.These intersecting light beams 15a, 15b are used in particular in one embodiment of the atom gyroscope.

[0056] Figure 5 shows an alternative design of a second exemplary embodiment of a beam path with three mirrors, in which the first light beam 15a is deflected by a first mirror 35a by 90 degrees relative to its original exit direction. The second light beam 15b is deflected by a second mirror 35b by 90 degrees relative to its original exit direction and then strikes a third mirror 35c, which mirror is arranged symmetrically to a plane perpendicular to the beam direction of the 90-degree deflected beam path of the second light beam 15b and is thus at a 45-degree angle to the direction of the second light beam 15b impinging on it. At the third mirror 35c, the incident second light beam 15b is thus deflected again by 90 degrees and is thus guided through the beam guiding optics in a direction opposite to the original exit direction.The third mirror 35c is offset from the second mirror 35c in an X direction X and arranged at a distance from the first mirror 35a. Furthermore, the second mirror 35b is offset from the first mirror 35a in an X direction X and arranged at a distance from the first mirror 35a, wherein the distance in the X direction X between the first mirror 35a and the second mirror 35b is smaller than the distance between the third mirror 35c and the second mirror 35b. After the previously described deflections due to the reflections at the mirrors 35a, 35b, 35c, the first light beam 15a intersects the second light beam 15b. These intersecting light beams 15a, 15b are used in particular in another embodiment of the atomic gyroscope.

[0057] The features described or shown in the above description, the claims, the exemplary embodiments, and the figures may be important, individually or in any combination, for implementing the various embodiments of the invention. Upon reading the present disclosure, further modifications of the invention that are customary in the art will become apparent. Such modifications may include other features already known in the art that may be used instead of or in addition to the features already described herein. Modifications of the disclosed invention and its embodiments can be understood and implemented based on the drawings, the disclosure, and the claims.

[0058] Reference symbol Emitter device 1 Printed circuit board 2a First printed circuit board 2ab Second printed circuit board 2b Housing 3 TEC system 4a First TEC system 4ab Second TEC system 4b Emitter 5a First emitter 5ab Second emitter 5b Current driver 6a First current driver 6ab Second current driver 6b Printed circuit board voltage source 7 Current conductor 8 Voltage source 90 Power connector 101a Thermal contact 11a1b Thermal contact 11b2a DC conductor 12a2b DC conductor 12b3 Controller 134 Serial interface 145a First light beam 15a5b Second light beam 15b6a First current conductor 16a6b Second current conductor 16b6c Third current conductor 16c6d Fourth current conductor 16d6e Fifth current conductor 16e 17 Control signal 17

[0059] 17a First control signal path 17a

[0060] 17b Second control signal path 17b

[0061] 17c Third control signal path 17c

[0062] 17d Fourth control signal path 17d

[0063] 18 Control loop 18

[0064] 19 PID controller 19

[0065] 20 Measuring resistor 20

[0066] 21 Instrument Amplifiers 21

[0067] 22 Emitter current 22

[0068] 23 Digital-to-analog converter voltage 23

[0069] 24 Integrator voltage 24

[0070] 25 Current driver voltage 25

[0071] 26 Measuring resistance voltage with offset amount 26

[0072] 27 Measuring resistance voltage 27

[0073] 28 Control signal 28

[0074] 29 Control signal generation 29

[0075] 30 Voltage with offset amount 30

[0076] 31 Input 31

[0077] 32 Determination 32

[0078] 33 Measured error 33

[0079] 34 Measured value 34

[0080] 35 Mirrors 35

[0081] X X-direction X

Claims

Claims 1. Emitter device (1) comprising a plurality of emitters (5) for emitting light; a plurality of current drivers (6) which are designed and configured to supply at least one of the emitters (5) with electrical current; a plurality of TEC systems (4) which are designed and configured to regulate the temperature of at least one of the emitters (5) and in particular of at least one of the current drivers (6); wherein at least one of the current drivers (6) and one of the TEC systems (4) is assigned to each individual emitter (5).

2. Emitter device (1) according to claim 1, comprising a plurality of circuit boards (2), wherein each of the emitters (5) and the current drivers (6) and TEC systems (4) associated therewith are arranged on one of the circuit boards (2).

3. Emitter device (1) according to claim 1 or 2, wherein at least one of the TEC systems (4) is arranged in thermal contact with at least one of the emitters (5) and at least one of the current drivers (6).

4. Emitter device (1) according to the preceding claim, in which the TEC system (4), in particular the TEC element, is arranged in thermal contact with exactly one emitter (5) and preferably exactly one of the current drivers (6).

5. Emitter device (1) according to one of the preceding claims, wherein the TEC systems (4) are designed and configured to keep the current drivers (6) and / or the emitters (5) at a constant temperature.

6. Emitter device (1) according to one of claims 2 to 5, comprising a circuit board voltage source (7) which is arranged on or on a first circuit board (2a).

7. Emitter device (1) according to the preceding claim, wherein the circuit board voltage source (7) is designed and arranged to supply power to all TEC systems (4) and all current drivers (6).

8. Emitter device (1) according to one of claims 2 to 7, comprising a controller (13) which is arranged on or on a second circuit board (2b).

9. Emitter device (1) according to the preceding claim when referring back to one of claims 6 to 8, wherein the circuit board voltage source (7) is designed and arranged to supply power to the controller (13).

10. Emitter device (1) according to the preceding claim, wherein the controller (13) is arranged in connection with a serial interface (14) or has a serial interface (14).

11. Emitter device (1) according to one of claims 9 or 10, wherein the controller (13) is designed and arranged to control all TEC systems (4) and all current drivers (6).

12. Emitter device (1) according to one of claims 2 to 11, wherein the circuit boards (2) are arranged in a common housing (3).

13. Gyroscope comprising an emitter device (1) according to one of the preceding claims.

14. Control circuit (18) for an emitter device (1) according to one of the preceding claims, comprising a PID controller (19), in particular an integrator (19); a measuring resistor (20); and an instrumentation amplifier (21); in which at least one of the current drivers (6) is arranged between the PID controller (19) and the measuring resistor (20) and is electrically connected thereto; and in which the instrumentation amplifier (21) is arranged between the PID controller (19) and the measuring resistor (20) and is electrically connected thereto.

15. A method for operating a control circuit (18) according to the preceding claim, comprising the steps: Providing the control loop (18); Arranging the measuring resistor (20) between the current driver (6) and the instrument amplifier (21); Setting a voltage; Generating a control signal (28), in particular at the PID controller (19); Providing the control signal (28) to the current driver (6); Generating an emitter current (22) at the current driver (6); Applying the emitter current (22) to the emitter (5); Tapping the emitter current (22) at the measuring resistor (20); Providing a voltage to the instrumentation amplifier (21); Determining the voltage at the instrumentation amplifier (21); Comparison of the determined voltage with the set voltage; Adaptation of the control signal (28) depending on the comparison.

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