# US 10,119,727 B2 · Mechanical relay and solid-state relay for controlling heating elements > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,119,727 B2 - Document ID: US10119727B2 - Status: Granted - Kind: B2 - Application number: 14/705,376 - Filed: 2015-05-06 - Published: 2016-11-10 - Granted: 2018-11-06 - Earliest claimed: 2015-05-06 - Assignees: Infineon Technologies AG - Applicants: Infineon Technologies AG - Inventors: Alfons Graf; Thomas Klug - Web page: https://patentgrep.com/patent/US10119727B2 ## CPC - H05B 1/0236: {for vehicles} - F24H 2250/04: Positive temperature coefficients [PTC]; Negative temperature coefficients [NTC] - H02H 3/202: {for DC systems} - H02H 7/222: {for switches} - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL - F24H: FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL (steam generation F22) - H02H: EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS (indicating or signalling undesired working conditions G01R, e.g. G01R31/00, G08B; locating faults along lines G01R31/08; emergency protective devices H01H) ## Abstract A circuit comprises a mechanical relay and a solid-state relay. The mechanical relay is configured to switch a first supply current of the first heating element on a first supply line. The solid-state relay is configured to switch a second supply current of a second heating element on a second supply line. ## Claims ### Claim 1 A circuit comprising: a mechanical relay configured to switch a first supply current of a first heating element on a first supply line; a solid-state relay configured to switch a second supply current of a second heating element on a second supply line, the second supply line being different than the first supply line; and a control device connected to an input interface and further connected to a control interface, wherein the control device is configured to: receive an input signal via the input interface; establish, depending on the input signal, a first control signal and a second control signal, wherein the first control signal prompts the mechanical relay to either switch on or switch off the first supply current on the first supply line, and wherein the second control signal prompts the solid-state relay to alternately switch on and off the second supply current on the second supply line; send the first control signal via the control interface to the mechanical relay; and send the second control signal via the control interface to the solid-state relay. ### Claim 2 (depends on 1) The circuit of claim 1, further comprising a connector configured to establish an electrical coupling between the second supply line and the second heating element, wherein the connector comprises: an electrical contact; a housing; and an engagement element configured to releasably attach the housing of the connector to the second heating element such that the electrical contact can engage with a counterpart electrical contact of the second heating element, wherein the solid-state relay is arranged within the housing of the connector. ### Claim 3 (depends on 2) The circuit of claim 2, wherein a largest outer dimension of the housing of the connector is smaller than 10 centimeters (cm), preferably smaller than 8 cm, more preferably smaller than 5 cm. ### Claim 4 (depends on 1) The circuit of claim 1, further comprising a fuse box comprising a housing, a first electrical fuse electrically coupled in series with the mechanical relay on the first supply line, and a second electrical fuse electrically coupled in series with the solid-state relay on the second supply line, wherein the first electrical fuse and the second electrical fuse are arranged inside the housing of the fuse box. ### Claim 5 (depends on 4) The circuit of claim 4, wherein the mechanical relay is arranged inside the housing of the fuse box, and wherein the solid-state relay is arranged inside the housing of the fuse box. ### Claim 6 (depends on 4) The circuit of claim 4, wherein the mechanical relay is arranged inside the housing of the fuse box, and wherein the solid-state relay is arranged outside the housing of the fuse box. ### Claim 7 (depends on 1) The circuit of claim 1, further comprising an electrical fuse connected in series with the solid-state relay. ### Claim 8 (depends on 1) The circuit of claim 1, wherein the solid-state relay comprises an overcurrent protection circuitry, wherein the circuit further comprises a fuse box comprising a housing and an electrical fuse electrically coupled in series with the mechanical relay on the first supply line, and wherein the electrical fuse is arranged inside the housing of the fuse box. ### Claim 9 (depends on 1) The circuit of claim 1, wherein the control device is configured to establish a set heating power based on the input signal, wherein the control device is configured to establish the first control signal depending on a threshold comparison between the set heating power and a predefined threshold, and wherein the control device is configured to establish the second control signal depending on a difference between the set heating power and the predefined threshold. ### Claim 10 (depends on 1) The circuit of claim 1, wherein the control device further comprises a processor configured to receive the input signal via the input interface and to process the input signal, wherein the input signal is a packetized encoded signal indicating a set heating power, and wherein the input interface operates according to at least one of the following: Controller Area Network Protocol, Media Oriented System Protocol, Local Interconnect Network Protocol. ### Claim 11 (depends on 1) The circuit of claim 1, wherein the input signal is a clocked logic signal indicating a set heating power. ### Claim 12 (depends on 1) The circuit of claim 1, wherein the second control signal is a pulse-width modulated logic signal. ### Claim 13 (depends on 1) The circuit of claim 1, wherein the solid-state relay further comprises at least one of a low-pass filter and a high-pass filter. ### Claim 14 A system, comprising: a mechanical relay configured to switch a first supply current of a first heating element on a first supply line; a solid-state relay configured to switch a second supply current of a second heating element on a second supply line, the second supply line being different than the first supply line; the first heating element; the second heating element; and a control device connected to an input interface and further connected to a control interface, wherein the control device is configured to: receive an input signal via the input interface; establish, depending on the input signal, a first control signal and a second control signal, wherein the first control signal prompts the mechanical relay to either switch on or switch off the first supply current on the first supply line, and wherein the second control signal prompts the solid-state relay to alternately switch on and off the second supply current on the second supply line; send the first control signal via the control interface to the mechanical relay; and send the second control signal via the control interface to the solid-state relay. ### Claim 15 (depends on 14) The system of claim 14, wherein the second heating element comprises a housing, and wherein the solid-state relay and heating wiring of the second heating element are arranged at least partly inside the housing of the second heating element. ### Claim 16 (depends on 14) The system of claim 14, wherein a low-side wiring of the second supply line is twisted around a high-side wiring of the second supply line. ### Claim 17 (depends on 14) The system of claim 14, wherein the first heating element comprises first positive-temperature-coefficient or resistive heating wiring, and wherein the second heating element comprises second positive-temperature-coefficient or resistive heating wiring. ### Claim 18 A method, comprising: receiving by a control device connected to an input interface and further connected to a control interface, an input signal via the input interface; establishing, by the control device and depending on the input signal, a first control signal and a second control signal; sending, by the control signal, the first control signal via the control interface to a mechanical relay; and sending, by the control device, the second control signal via the control interface to a solid-state relay, the first control signal prompting the mechanical relay to either switch on or switch off a first supply current of a first heating element on a first supply, and the second control signal prompting the solid-state relay to alternately switch on and off a second supply current of a second heating element on a first supply line, the second supply line being different than the first supply line. ### Claim 19 (depends on 18) The method of claim 18, wherein establishing the first control signal and the second control signal comprises: establishing a set heating power based on the input signal; establishing the first control signal depending on a threshold comparison between the set heating power and a predefined threshold; and establishing the second control signal depending on a difference between the set heating power and the predefined threshold. ### Claim 20 (depends on 14) The system of claim 14, wherein the control device is configured to establish a set heating power based on the input signal, wherein the control device is configured to establish the first control signal depending on a threshold comparison between the set heating power and a predefined threshold, and wherein the control device is configured to establish the second control signal depending on a difference between the set heating power and the predefined threshold.