An electrical resonance network comprising a first capacitor and a first inductor whose resonance frequency can be tuned by means of a second capacitor and/or a second inductor. The resulting effective capacitor- or inductor value of a network period is controlled by a variable coupling respectively decoupling interval by means of at least one coupling switch. The coupling respectively decoupling interval is synchronized by a sign change of a current and/or voltage in the network.

An electrical resonance network comprising a first capacitor and a first inductor whose resonance frequency can be tuned by means of a second capacitor and/or a second inductor. The resulting effective capacitor- or inductor value of a network period is controlled by a variable coupling respectively decoupling interval by means of at least one coupling switch. The coupling respectively decoupling interval is synchronized by a sign change of a current and/or voltage in the network.

A method of selecting a signal input includes the steps of transmitting an audio signal to an audio input of a device that includes a plurality of audio inputs. A setting of the device is automatically advanced from a currently set audio input to another one of the audio inputs when the device does not output a signal associated with said audio signal.

A device such as a television automatically determines, on initial power up, its geographical location. If the television is determined to be residing in a retail store location it will automatically default to retail mode where picture and audio quality will be set to pre-specified settings conducive to a retail environment where the ambient light and sound levels are not what would typically be found in a residential environment. The invention consists of a software module and a database resident in the television that can determine, from interrogating either a GPS chip set, or obtaining identifying data from an attached wired or wireless network and matching the data to identifying data for retail store locations to determine if the television is located in a retail store. If the location of the television is determined to be in a retail store the television will initialize the video and audio quality for a retail store environment. If the location of the television is determined to not be in a retail store, the television will initialize the video and audio quality for a residential environment.

A method for switching mode of a source device that uses a High Definition Multimedia Interface (HDMI) according to an embodiment of the present invention may include connecting to a sink device through the HDMI; transmitting +5V signal to the sink device; receiving a Hot Plug Detect (HPD) signal from the sink device; receiving EDID information including a first Sideband mode support information representing that the sink device supports a Sideband mode through a Display Data Channel (DDC) channel that operates in a DDC mode; transmitting a second Sideband mode support information representing that the source device supports a Sideband mode to the sink device; receiving instruction to perform an operation mode switching of the DDC channel from the sink device; and switching the operation mode of the DDC channel from the DDC mode to the Sideband mode.