Circuit arrangement for controlling a plurality of electrical loads

Abstract

Circuit arrangement for controlling a plurality of electrical loads. A circuit arrangement for controlling a plurality of loads of an electrical appliance is disclosed. The circuit arrangement comprises a main control module arranged in a first voltage range of the circuit arrangement and configured to generate control data for controlling a first load from the plurality of loads; wherein the plurality of loads are arranged in a second voltage range. The circuit arrangement further comprises a galvanic isolation unit configured to transfer the control data from the first voltage range to the second voltage range via a galvanic isolation connection. Furthermore, the circuit arrangement comprises at least one auxiliary control module comprising a plurality of control outputs for a corresponding plurality of loads. The auxiliary control module comprises a light emitting diode (LED) driver embodied to operate a corresponding plurality of LED arrangements via the plurality of control outputs and / or a general purpose input / output (GPIO) expansion circuit, wherein the behavior of the plurality of control outputs can be programmed.

Description

[0001] The present invention relates to a circuit arrangement for controlling multiple electrical loads, such as, for example, power switching elements.

[0002] Household appliances such as washing machines or dishwashers typically have different electrical loads, such as electric motors, valves, pumps, switching elements, etc., arranged in the FELV (functional ultra-low voltage) range of the appliance. On the other hand, different electrical loads are usually controlled by one or more microcontrollers arranged in the SELV (safe ultra-low voltage) range or the PELV (protective ultra-low voltage) range.

[0003] Current isolation between control modules, particularly microcontrollers, in the PELV / SELV range and several different electrical loads in the FELV range is typically associated with relatively high cost. This document addresses the technical objective of enabling electrical loads in an appliance to be controlled efficiently (in terms of cost, weight, and / or installation space) and in a current-isolated manner.

[0004] This objective is achieved through the subject matter of the independent claims. Advantageous embodiments are particularly defined in the dependent claims, described in the following description, or illustrated in the drawings.

[0005] According to one aspect of the invention, a circuit arrangement (also referred to as a circuit device) for controlling multiple loads of an electrical appliance, particularly a household appliance, is described. Exemplary household appliances include washing machines, dishwashers, dryers, refrigerators, cookers, ovens, etc. The electrical loads of the appliance can be configured to provide the appliance's functions, such as heating, cooling, driving, etc. Exemplary electrical loads are: electrically driven valves, electrically driven motors, electrically driven heaters, electrically driven pumps, and / or electrically switching elements, particularly relays, triacs, transistors, and MOSFETs. The electrically switching elements are particularly useful for switching (e.g., activating or deactivating) another load, such as a valve, motor, heater, pump, etc.

[0006] The circuit arrangement includes a main control module (e.g., a microcontroller) positioned within a first voltage range of the circuit arrangement and configured to generate control data for controlling a first load among multiple loads. The control data may include control instructions for a specific load of the appliance, such as activating or deactivating the load or setting and / or changing the load's power consumption or output. The first voltage range may be a Safe Extra-Low Voltage (SELV) or Protective Extra-Low Voltage (PELV) range.

[0007] Multiple loads can be arranged in a second voltage range different from the first voltage range. Here, the second voltage range may belong to a different protection class than the first voltage range. In particular, the second voltage range may be a functional extra-low voltage (FELV) range.

[0008] Furthermore, the circuit arrangement includes a current isolation unit configured to transmit control data from a first voltage range to a second voltage range via a current isolation connection. The current isolation unit may include, for example, an optocoupler, a capacitive coupler, and / or an inductive coupler.

[0009] The circuit arrangement further includes at least one auxiliary control module, which includes multiple control outputs for corresponding multiple loads. The at least one auxiliary control module can be configured to control the multiple control outputs independently of each other, and in particular, to switch them independently of each other.

[0010] The auxiliary control module may have a data input through which it can receive control data from the current isolation unit. The received control data can then be used to operate one or more control outputs. Specifically, the current and / or voltage can be set at at least one control output based on the control data.

[0011] The auxiliary control module may include a light-emitting diode (LED) driver, or the auxiliary control module may be embodied as an LED driver. The LED driver may be embodied as operating corresponding multiple LED arrangements (e.g., LEDs or LED chains) via multiple control outputs. In particular, multiple control outputs may be provided for controlling LED arrangements with different colors, especially red (R), green (G), and / or blue (B) LED arrangements.

[0012] Alternatively or additionally, the auxiliary control module may include, or may be embodied as, general purpose input / output (GPIO) expansion circuitry or expanders. GPIO circuitry or expanders may be embodied in a way that allows the behavior of multiple control outputs to be programmed (by the user, possibly freely programmable).

[0013] In this way, one or more cost-effective auxiliary control modules can be used, particularly in a manner deviating from their original purpose, in a second voltage range to control individual electrical (power) loads. Here, one or more auxiliary control modules can be configured in each case to identify a first control output from among multiple control outputs used to control the first load based on control data. The control data can have identifiers (such as bit codes) for, for example, the first load or the first control output. The auxiliary control modules can be embodied in assigning control data, particularly control instructions contained within the control data, to the first control output based on the identifiers.

[0014] Furthermore, one or more auxiliary control modules can be configured to control the first load via the first control output. Control data may include control instructions for the first load (in addition to an identifier for the first load). The auxiliary control modules can be configured to operate the first control output according to the control instructions. Specifically, voltage levels and / or currents can be set at or near the first control output according to the control instructions.

[0015] Therefore, a circuit arrangement is described that uses one or more auxiliary control modules (particularly one or more LED driver chips and / or one or more GPIO expander chips) in a second voltage range to control different loads of an appliance. This allows for the efficient control of several different loads in the second voltage range using a single current isolation unit. Furthermore, LED driver chips and / or GPIO expander chips are widely used for other purposes (particularly for controlling LED-based optical elements) and can therefore be provided cost-effectively for controlling the electrical loads of an appliance (in a manner deviating from their original purpose).

[0016] The auxiliary control module can be configured to set the voltage level of the first control output to high or low based on control data, particularly control commands for the first load. In this way, the first load can be reliably controlled, specifically activated or deactivated, or turned on or off. When the auxiliary control module, particularly the LED driver, is used for its original purpose, the voltage level at the first control output can be used to activate or deactivate the LED arrangement connected to the first control output.

[0017] Alternatively or additionally, the auxiliary control module, particularly the LED driver of the auxiliary control module, or the auxiliary control module implemented by means of the LED driver, can be embodied as: setting the (first) current at the first control output by means of pulse width modulation (PWM) based on control data, particularly based on control instructions for the first load, in order to set the power of the first load, such as mechanical power, heating power, etc.

[0018] An LED driver can be configured to dim LEDs connected to its control output via PWM. The pulse width can be decreased or increased to correspondingly decrease or increase the current intensity at the control output. This dimming mechanism of the LED driver can be used in circuit arrangements for controlling the electrical loads of appliances. In this way, highly efficient and precise control of different electrical loads within an appliance becomes possible.

[0019] The circuit arrangement may include a first auxiliary control module and a second auxiliary control module, which are arranged, in particular, cascaded, within the second voltage range. Here, the auxiliary control modules may have identical designs. In each case, the auxiliary control module may have a data input (in particular a data input pin), through which control data can be received by the corresponding auxiliary control module. Furthermore, in each case, the auxiliary control module may have a data output (in particular a cascade pin), through which control data can be forwarded to the downstream auxiliary control module. The auxiliary control modules can thus be embodied for cascading, wherein the data input of the downstream auxiliary control module is connected to the data output of the upstream auxiliary control module. Therefore, control data can be forwarded in a cascaded manner from one auxiliary control module to an auxiliary control module directly located downstream. In this way, the number of electrical loads that can be controlled in the second voltage range via the main control module (arranged in the first voltage range) can be adjusted, in particular increased, in a highly efficient and flexible manner.

[0020] When using the first and second auxiliary control modules, the first auxiliary control module may include multiple first control outputs for corresponding multiple first loads. The second auxiliary control module may include multiple second control outputs for corresponding multiple second loads. For example, each auxiliary control module may be configured to control two or more, three or more, or four or more electrical loads of the appliance. Here, in each case, the individual control outputs may be constructed identically.

[0021] The first auxiliary control module can be characterized by forwarding control data received via a current isolation unit, particularly via a cascaded pin of the first auxiliary control module, to the second auxiliary control module. Specifically, the first auxiliary control module can be characterized as a shift register that forwards control data to the second auxiliary control module according to a periodic interval.

[0022] The main control module can be manifested by transmitting control data to the auxiliary control module via line code, particularly binary line code (such as non-return-to-zero (NRZ) code). In this way, it is possible to control several different loads with particularly high efficiency.

[0023] According to another aspect, a household appliance (e.g., a washing machine, dishwasher, oven, cooker, kitchen appliance, vacuum cleaner, dryer, refrigerator, etc.) is described, which includes the circuit arrangement described in this document. The household appliance may include a power connection for connecting the appliance to an AC supply voltage. Furthermore, the household appliance may include a switching power supply and / or one or more voltage transformers, which are embodied in providing several different voltage ranges within the appliance based on the AC supply voltage (e.g., for operating the main control module on one hand, and for operating several different electrical loads on the other).

[0024] It should be noted that any aspect of the circuit arrangement described in this document can be combined with each other in a variety of ways. In particular, the features of the claims can be combined with each other in a variety of ways.

[0025] The invention will now be described in more detail with reference to the exemplary embodiments illustrated in the accompanying drawings, wherein: Figure 1a A block diagram of an exemplary household appliance is shown; Figure 1b An exemplary current isolation between the control module and the load of a household appliance is shown; and Figure 2 Exemplary circuit arrangements for controlling electrical appliances, particularly household appliances, are shown.

[0026] As stated in the introduction, this document itself relates to efficient current isolation control of electrical appliances, particularly household appliances, across different loads and especially different switching elements. In this context, Figure 1a An exemplary household appliance 100 (e.g., a washing machine) is shown, which has a power transmission connection 102, and in particular a switching mode power supply, through which the household appliance 100 can be connected to an AC supply voltage 103.

[0027] If passed Figure 1b As illustrated in the example, a household appliance 100 typically includes one or more control modules 121 configured to control different electrical loads 123 of the household appliance 100, particularly different electrical switching elements. Specifically, control commands 124 can be transmitted from the control module 121 to the electrical loads 123, for example, to activate or deactivate the electrical loads 123.

[0028] The control module 121 for the electrical load 123 can be arranged in the SELV / PELV range 131 of the household appliance 100, while the electrical load 123 is arranged in the FELV range 132 of the household appliance 100. Therefore, the current isolation unit 122 is arranged between the control module 121 and the electrical load 123 and is configured to transmit control commands 124 from the control module 121 to the electrical load 123 via a current-isolated communication connection.

[0029] The household appliance 100 may therefore include different electrical loads 123 (such as, for example, several valves, one or more motors, heaters, one or more pumps, etc.), which can be switched as needed via corresponding one or more relays, triac switching elements, transistors, MOSFETs, etc. One or more switching elements 123 are actuated by one or more control modules 121, particularly microcontrollers.

[0030] For safety reasons and / or as a protective measure and / or to avoid ground loops and / or to avoid potential shifts, the actuation of the switching element 123 typically occurs in a current-isolated manner. The current isolation for the actuation of the power switching element 123 occurs, for example, optically (using an optocoupler, opto-isolating switch, etc.), inductively (using a transformer), or capacitively (using a capacitive coupler, capacitor, etc.). In this way, individual switching elements 123 can be switched via a microcontroller supplied by SELV or PELV.

[0031] Current isolation between the control module 121 and the different loads 123 can be achieved by using a dedicated current isolation unit 124 for each individual load 123. Alternatively, an additional control module (specifically an additional microcontroller) can be used, which communicates with the main control module 121 via a separate data bus. Current-isolated actuation of the individual loads 123 can be implemented by the additional control module.

[0032] The aforementioned measures for current isolation are typically associated with relatively high costs, particularly for installing dedicated isolation units 124 for each individual load 123 or for installing additional microcontrollers. Furthermore, relatively large isolation trenches are usually required between the SELV / PELV range 131 and the FELV range 132.

[0033] Figure 2A circuit arrangement 200 with a main control module 121 is shown, which is arranged in a first voltage range 131 (particularly in the SELV or PELV range). The main control module 121 is connected to one or more auxiliary control modules 201 via a current isolation unit 122. Here, the auxiliary control modules 201 are configured to control one or more loads 123. In particular, the auxiliary control modules 201 may have one or more control outputs 204 for controlling the corresponding one or more loads 123. One or more auxiliary control modules 201 of the circuit arrangement 200 are arranged in a second voltage range 132 (particularly in the FELV range).

[0034] The main control module 121 is configured to transmit control data 202 to one of the auxiliary control modules 201 via isolation unit 122. Here, the control data 202 may indicate an identifier of the load 123 to which the control data 202 is intended, and in particular, the identifier of the control output 204 to which the load 123 is connected, and the identifier of the auxiliary control module 201. Furthermore, the control data 202 may contain control instructions 124 for the load 123 indicated by the identifier (e.g., control instructions 124 for activating or deactivating the load 123, or control instructions 124 for setting the power of the load 123).

[0035] The auxiliary control module 201 of the circuit layout 200 can be configured to examine the control data 202 transmitted by the main control module 121 to determine whether the control data 202 is intended for the load 123 connected to the control output 204 of the auxiliary control module 121. If not, the auxiliary control module 121 can ignore the control data 202. If so, a control command 124 can be forwarded to the identified control output 204 of the auxiliary control module 121. This allows different loads 123 to be controlled efficiently across different voltage ranges 131, 132.

[0036] In a preferred example, the auxiliary control module 121 is or includes an LED (light-emitting diode) driver, particularly a single-wire LED driver, or a GPIO (general purpose input / output) expander. In this way, a particularly efficient circuit layout 200 can be provided.

[0037] The use of a single-wire LED driver or GPIO expander 201 enables actuation not only of LEDs but also of other loads 123. Only a single current isolation element 122 is required here. Furthermore, control outputs 204, specifically chip pins, can be used for individual loads 123 in each case. The use of an LED driver or GPIO expander 201 within the FELV range 132 makes it possible to reduce the PCB area of ​​the circuit layout 200 by reducing the number of isolation elements 122 between the SELV / PELV 131 and the FELV 132. The main microcontroller 121 can transmit line code 202 (e.g., a non-return-to-zero code) as an actuation signal 123 to the driver 201 via the current isolation element 122. The driver 201 can then switch the load 123 directly or via a power switch.

[0038] Driver 201 can be configured to switch several outputs 204 independently of each other. Cascading several drivers 201 is also possible. Here, the cascading of drivers 201 can operate as a shift register, where the cycle time is generated by the driver 201 itself and / or transmitted individually. As a result, a virtually unlimited number of drivers 201 can be linked together, and thus actuate a corresponding number of loads 123.

[0039] In particular, taking into account the fact that fewer current isolation elements 122 can be used and / or the fact that LED drivers 201 can be mass-produced, using LED drivers 201 for loads 123 in actuating devices 100 allows loads 123 to be actuated in a particularly cost- and space-efficient manner. Furthermore, the cascading of drivers 201 allows for flexible adjustment of the number of controlled loads 123. Additionally, the PCB (printed circuit board) area required for the isolation trenches between voltage ranges 131 and 132 can be reduced.

[0040] This invention is not limited to the exemplary embodiments described. In particular, it should be noted that the description and figures are intended only to illustrate the principles of the proposed circuit arrangement.

Claims

1. A circuit arrangement (200) for controlling multiple loads (123) of an electrical appliance (100); wherein the circuit arrangement (200) includes - A main control module (121) is arranged in a first voltage range (131) of the circuit arrangement (200) and is configured to generate control data (202) for controlling a first load (123) from the plurality of loads (123); wherein the plurality of loads (123) are arranged in a second voltage range (132); - Current isolation unit (122) configured to transmit control data (202) from a first voltage range (131) to a second voltage range (132) via a current isolation connection; - At least one auxiliary control module (201) includes multiple control outputs (204) for corresponding multiple loads (123); wherein the auxiliary control module (201) includes - A light-emitting diode (LED) driver, which is embodied as operating a plurality of corresponding LED arrangements via the plurality of control outputs (204), and / or - General Purpose Input / Output (GPIO) expansion circuitry, wherein the behavior of the multiple control outputs (204) can be programmed; and The auxiliary control module (201) is configured based on the control data (202) as follows: - Identify the first control output (204) for controlling the first load (123) from the plurality of control outputs (204); and - This causes the first load (123) to be controlled via the first control output (204).

2. The circuit arrangement (200) as described in claim 1, wherein, The auxiliary control module (201) is configured to set the voltage level of the first control output (204) to high or low based on the control data (202) in order to activate or deactivate the first load (123).

3. The circuit arrangement (200) as described in any of the preceding claims, wherein - The auxiliary control module (201) includes an LED driver; and - The LED driver is configured to set a first current at a first control output (204) by means of pulse width modulation based on control data (202) in order to set the power of a first load (123).

4. The circuit arrangement (200) as described in any of the preceding claims, wherein - The auxiliary control module (201) includes an LED driver; and - Provide the multiple control outputs (204) for controlling the arrangement of LEDs with different colors.

5. The circuit arrangement (200) as described in any of the preceding claims, wherein - The circuit layout (200) includes a first auxiliary control module (201) and a second auxiliary control module (201), which are arranged within a second voltage range (132); - The first auxiliary control module (201) includes a plurality of first control outputs (204) for corresponding plurality of first loads (123); - The second auxiliary control module (201) includes a plurality of second control outputs (204) for corresponding plurality of second loads (123). - The first auxiliary control module (201) is configured to forward control data (202) received via the current isolation unit (122) to the second auxiliary control module (201).

6. The circuit arrangement (200) as described in claim 5, wherein, The first auxiliary control module (201) is embodied as a shift register, which forwards control data (202) to the second auxiliary control module (201) according to the periodic time.

7. The circuit arrangement (200) as described in any of the preceding claims, wherein, The main control module (121) is manifested by transmitting control data (202) to the auxiliary control module (201) via line code.

8. The circuit arrangement (200) as described in any of the preceding claims, wherein, The auxiliary control module (201) is configured to switch the plurality of control outputs (204) independently of each other.

9. The circuit arrangement (200) as described in any of the preceding claims, wherein the plurality of loads (123) comprises one or more of the following: an electrically driven valve, an electrically driven motor, an electrically driven heater, an electrically driven pump and / or an electrically switching element.

10. The circuit arrangement (200) as described in any of the preceding claims, wherein - The first voltage range (131) is the Safety Extra Low Voltage (SELV) or Protective Extra Low Voltage (PELV) range; and / or - The second voltage range (132) is the functional ultra-low voltage (FELV) range.

11. The circuit arrangement (200) of claim 4, wherein the LED arrangement with different colors includes red, green and / or blue LED arrangements.

12. The circuit arrangement (200) as described in claim 5, wherein the first auxiliary control module (201) and the second auxiliary control module (201) are cascaded within the second voltage range (132).

13. The circuit arrangement (200) as claimed in claim 5, wherein the current isolation unit (122) is a cascaded pin.

14. The circuit arrangement (200) as described in claim 7, wherein the line code is a non-return-to-zero code.

15. The circuit arrangement (200) as described in claim 9, wherein the electrical switching element is one of a relay, a triac, a transistor, or a MOSFET.

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