POWER ELECTRONICS ASSEMBLY AND DOMESTIC APPLIANCE

Abstract

A power electronics assembly of a domestic appliance includes a first relay controlling an electrical contact between a first current-carrying conductor and an electric consumer. The assembly further includes a semiconductor switching element that switches the electrical contact between the first current-carrying conductor and the electric consumer and is arranged in parallel with the first relay. A controller is programmed to activate the semiconductor switching element to switch on the electrical consumer before the first relay is closed.

Claims

1. A power electronics assembly of a domestic appliance comprising: a first relay controlling an electrical contact between a first current-carrying conductor and an electric consumer of the domestic appliance; a semiconductor switching element that switches the electrical contact between the first current-carrying conductor and the electric consumer and is arranged in parallel with the first relay; and a controller programmed to activate the semiconductor switching element to switch ON the electric consumer before the first relay is closed.

2. The power electronics assembly according to claim 1, wherein the controller is further programmed to stop the activation of the semiconductor switching element after the first relay has closed.

3. The power electronics assembly according to claim 1 further comprising a second relay controlling an electrical contact between a second current-carrying conductor and the electric consumer, wherein the controller is further programmed to close the second relay to switch ON the electric consumer before the semiconductor switching element is activated.

4. The power electronics assembly according to claim 1, wherein the controller is further programmed to activate the semiconductor switching element before the first relay has opened in order to switch OFF the electric consumer.

5. The power electronics assembly according to claim 4, wherein the controller is further programmed to stop the activation of the semiconductor switching element after the first relay has opened and before the second relay has opened in order to switch OFF the electric consumer.

6. The power electronics assembly according to claim 4, wherein the controller is further programmed to stop the activation of the semiconductor switching element after the first relay has opened in order to switch OFF the electric consumer.

7. The power electronics assembly according to claim 1, wherein the semiconductor switching element includes a TRIAC.

8. The power electronics assembly according to claim 1, wherein the first relay includes a monostable switching state.

9. The power electronics assembly according to claim 3, wherein the first and the second relay each include a monostable switching state.

10. The power electronics assembly according to claim 1, further comprising a galvanic isolation between the current-carrying conductor(s) and the controller.

11. The power electronics assembly according to claim 1, further comprising a fusible link in a connection line of the controller or a smoothing capacitor between connection lines of the controller.

12. The power electronics assembly according to claim 1, wherein the electric consumer is an ohmic consumer.

13. The power electronics assembly according to claim 12, wherein the ohmic consumer is a heating element.

14. A domestic appliance comprising: an electric consumer; a first relay controlling an electrical contact between a first current-carrying conductor and the electric consumer; a semiconductor switching element that switches the electrical contact between the first current-carrying conductor and the electric consumer and is arranged in parallel with the first relay; and a controller programmed to activate the semiconductor switching element to switch ON the electric consumer before the first relay is closed.

15. The domestic appliance of claim 14, wherein the electric consumer is a heating element.

16. The domestic appliance of claim 14, wherein the controller is further programmed to stop the activation of the semiconductor switching element after the first relay has closed.

17. The domestic appliance according to claim 14 further comprising a second relay controlling an electrical contact between a second current-carrying conductor and the electric consumer, wherein the controller is further programmed to close the second relay to switch ON the electric consumer before the semiconductor switching element is activated.

18. The domestic appliance according to claim 17, wherein the controller is further programmed to activate the semiconductor switching element before the first relay has opened in order to switch OFF the electric consumer.

19. A hot water heater comprising: an electric heating element; a first relay controlling an electrical contact between a first current-carrying conductor and the heating element; a semiconductor switching element that switches the electrical contact between the first current-carrying conductor and the electric consumer and is arranged in parallel with the first relay; and a controller programmed to activate the semiconductor switching element to switch ON the heating element before the first relay is closed.

20. The hot water heater of claim 19, wherein the controller is further programmed to stop the activation of the semiconductor switching element after the first relay has closed.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0039] FIG. 1 schematically illustrates an exemplarily circuit diagram of a power electronics assembly.

[0040] FIG. 2 schematically shows exemplarily circuit diagram for switching the electrical consumer ON and OFF.

DETAILED DESCRIPTION

[0041] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

[0042] FIG. 1 shows schematically and by way of example a circuit diagram of a power electronics assembly 1 according to one or more embodiments of this disclosure. The power electronics assembly 1 is designed, for example, as an assembly of a domestic appliance, e.g., a hot water appliance, such as a quick heater, storage water heater, water boiler, and controls or regulates the activation of an electric consumer BHZ, for example, a tubular heater or a bare wire heater.

[0043] The power electronics assembly 1 or the entire domestic appliance is connected to two current-carrying conductors, for example, of a low-voltage network, which are referred to herein as phase or conductor L, and neutral conductor N. The possibility of a reverse connection, which is easily possible according to the disclosure, is indicated in brackets.

[0044] The electrical consumer BHZ is arranged between the two conductors L, N and can be disconnected or connected in each case by an upstream relay K1 or K2 in the first conductor L or the second conductor N, respectively. This ensures that the voltage-carrying phase, i.e., the L conductor, is disconnected before the BHZ electrical consumer when both are connected.

[0045] A semiconductor switching element Q1 is arranged in parallel with the relay K1 in the first conductor L. The semiconductor switching element Q1 is preferably configured as a TRIAC.

[0046] A regulator or controller 10 is arranged galvanically isolated from the conductors L, N. All known types of galvanic isolation are conceivable here, of which only one is shown as an example in the circuit diagram.

[0047] The controller 10 may be designed to close the relay K1 and the relay K2. The relay K1 and/or the relay K2 may be relays with a monostable switching state so that the relay or relays are open when no control current provided by the control 10 is applied. The relay(s) is/are closed only when the control current is applied.

[0048] A fusible link SLS and a smoothing capacitor may be provided upstream of the control 10.

[0049] Switching on the electrical consumer BHZ is carried out in the following switching sequence, which is also shown schematically in FIG. 2 under the heading “ON”.

[0050] 1. Closing of relay contact K2.

[0051] This is done without current since the electric circuit is not yet closed in this case due to the initially still open contacts of the relay K1 and the semiconductor switching element Q1.

[0052] 2. Closing/activating the semiconductor switching element Q1.

[0053] The semiconductor switching element Q1 closes the electric circuit, the heater or electrical consumer BHZ starts to heat.

[0054] 3. Closing of the relay contact K1

[0055] The relay K1 bridges the semiconductor switching element Q1 and takes over the current flow—in this case, there is no significant load on the relay contact since only a minimal differential voltage has to be bridged at the moment of switching on and the residual current already flows via the semiconductor switching element Q1.

[0056] 4. Opening the semiconductor switching element Q1

[0057] This step is optional since the semiconductor switching element Q1 becomes non-conductive as soon as the relay K1 is closed—however, the continuous activation is unnecessary.

[0058] Switching OFF is done analogously in reverse order, wherein two alternatives are shown for this purpose in FIG. 2, which are marked with OFF1 and OFF2.

[0059] 1. Closing/activating the semiconductor switching element Q1

[0060] While in alternative OFF1, the semiconductor switching element Q1 is first opened and then closed in a first step; in alternative OFF2, the semiconductor switching element Q1 is permanently activated during operation of the electrical consumer BHZ. Thus, with alternative OFF2, the optional step 4 has not been executed during switch-on.

[0061] 2. Opening of relay contact K1

[0062] By opening the relay K1, the activated or closed contact takes over the current from the relay K1 via the semiconductor switching element Q1, wherein the relay K1 can be opened without burn-off due to the closed or conducting semiconductor switching element Q1.

[0063] 3. Opening of the semiconductor switching element Q1

[0064] Opening of the semiconductor switching element Q1 takes place without wear. With that, the switching circuit is opened and the current flow is stopped.

[0065] 4. Opening of the relay contact K2.

[0066] Since the switching circuit is already open, relay K2 can now also be opened in voltage-free and wear-free manner.

[0067] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.