METHOD OF AND APPARATUS ADAPTED FOR CONTROLLING A POWER CONSUMPTION OF A MEDIA STREAM REPRODUCING DEVICE

Abstract

A method of controlling a power consumption of a media stream reproducing device having a wide input voltage range power supply includes receiving a media stream and providing an output signal representative of the received media stream. A mains supply voltage of the media stream receiver is monitored and, in case the measured mains supply voltage falls below a first level the method further includes one or more of providing an output signal representative of a message indicating the reduced mains supply voltage and advising a user to reduce the power consumption of at least the media stream reproducing device, or providing an output signal controlling a first reduction of the power consumption of the media stream reproducing device, or controlling a recording device operatively connected to the media stream reproducing device to record the received media stream for later reproduction.

Claims

1. A method of controlling a power consumption of a device that is powered from a single mains supply voltage source, the device having a wide input voltage range power supply circuit adapted to provide a constant output power over a wide mains supply voltage range, the method including: monitoring, in a monitoring circuit, the mains supply voltage of the device; in case the measured mains supply voltage is below a first level within the wide input voltage range of the power supply circuit, reducing the power consumption of the device and continuing monitoring the mains supply voltage while the power consumption of the device is reduced, wherein the method further includes, after the power consumption has been reduced and in case the mains supply voltage exceeds a second level for a first time period, cancelling the reduction of the power consumption of the device in response to a corresponding control signal, wherein a delay proper to the device is set to expire before the cancellation is executed.

2. The method of claim 1, further including determining an average normal mains power supply voltage at a location of the device and storing the determined average voltage in a memory, and setting the first and/or second level relative to the previously determined average normal mains power supply voltage.

3. The method of claim 1, wherein the device is a media stream reproducing device, and the method further includes: receiving, at an input of a media stream receiver, a media stream and providing an output signal representative of the received media stream; generating the control signal in response to the mains supply voltage rising above the second level, in response to extracting a corresponding signal from the media stream, or in response to receiving a corresponding signal over a channel that is independent from the channel carrying the media stream.

4. The method of claim 1, wherein the device is a media stream reproducing device, and the method further includes receiving, at an input of a media stream receiver, a media stream and providing an output signal representative of the received media stream, and wherein reducing the power consumption of the media stream reproducing device includes cancelling the immediate reproduction of the received media stream and controlling a recording device operatively connected to the media stream reproducing device to record the received media stream for later reproduction.

5. The method of claim 1, wherein the device is a media stream reproducing device, and the method further includes receiving, at an input of a media stream receiver, a media stream and providing an output signal representative of the received media stream, and wherein reducing the power consumption of the media stream reproducing device includes switching off of the media stream reproducing device, or putting the media stream reproducing device into a standby mode, or reducing the brightness and/or audio volume of the media stream reproducing device, or a spatial and/or temporal resolution of video content, or reducing a number of auxiliary tasks performed by a microprocessor of the media stream reproducing device, or reducing a number of channels or stations received and processed by the media stream reproducing device, or a combination thereof.

6. The method of claim 1, further including sending a message to a server when or after the power consumption of the device has been reduced, the message indicating why and which action has been initiated or carried out.

7. The method of claim 1, wherein the device is a media stream reproducing device, and the method further includes: receiving, at an input of a media stream receiver, a media stream and providing an output signal representative of the received media stream; while the power consumption of the media stream reproducing device is reduced, monitoring the media stream or a channel that is independent from the channel carrying the media stream for emergency warnings or messages, and temporarily cancelling or reducing the reduction of the power consumption of the media stream reproducing device for reproducing the emergency warning or message.

8. The method of claim 7, wherein temporarily cancelling or reducing the reduction of the power consumption of the media stream reproducing device includes intermittently cancelling or reducing the reduction of the power consumption of the media stream reproducing device while reproducing the emergency warning or message.

9. The method of claim 8, wherein reducing the power consumption of the media stream reproducing device comprises issuing a digital control signal to the media stream reproducing device, the digital control signal including, but not limited to a digital text message, an HDMI CEC command, or an email.

10. The method of claim 1, wherein the device is a media stream reproducing device, and the method further includes receiving, at an input of a media stream receiver, a media stream and providing an output signal representative of the received media stream, wherein the media stream is received over one or more of a digital broadband connection, cable, terrestrial or satellite radio or television broadcast, GSM, UMTS, LTE.

11. The method of claim 10, wherein reducing the power consumption of the media stream reproducing device includes changing reception of a currently received media stream from a first source to a second source.

12. The method of claim 1, including, when or after the power consumption of the media stream reproducing device has been reduced, inhibiting or cancelling the reduction of the power consumption in response to receiving a corresponding user input.

13. A device including a microprocessor, a memory for storing data and/or software instructions of a program executed by the microprocessor, wherein the device further includes a meter for measuring a mains supply voltage, wherein the device, when executing the software instructions, is configured to: monitor, in a monitoring circuit, the mains supply voltage; in case the measured mains supply voltage is below a first level within the wide input voltage range of the power supply circuit, reduce the power consumption of the device and continue monitoring the mains supply voltage while the power consumption of the device is reduced, wherein the device is further configured, after the power consumption has been reduced and in case the mains supply voltage exceeds a second level for a first time period, to cancel the reduction of the power consumption of the device in response to a corresponding control signal, wherein a delay proper to the device is set to expire before the cancellation is executed.

14. The device of claim 13, wherein the device includes a receiver adapted to receive a media stream over one or more of digital broadband signals, terrestrial, cable or satellite radio or television broadcast signals, GSM, UMTS, or LTE connections.

15. The device of claim 14, wherein the device is adapted to receive a media stream and to provide an output signal representative of the received media stream while receiving, the output signal being a visible image and/or an audio signal for reproduction on a display and/or a loudspeaker, or an electrical, electro-magnetic or optical signal for coupling to a display device and/or an audio amplifier.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The present method, its developments and embodiments, as well as exemplary apparatuses implementing aspects of the method, embodiments and developments thereof, will be described in the following with reference to the drawing, in which

[0044] FIG. 1 shows a basic exemplary block diagram of a media stream receiver having a display suitable for implementing the present method;

[0045] FIG. 2a shows a first exemplary power supply with a primary side voltage supervisor circuit suitable for use in accordance with the present method;

[0046] FIG. 2b shows a second exemplary power supply with a primary side voltage supervisor circuit suitable for use in accordance with the present method;

[0047] FIG. 3 shows a further exemplary power supply with a primary side voltage supervisor circuit suitable for use in accordance with the present method;

[0048] FIG. 4 shows an exemplary graphic representation of various mains power supply voltages and respective actions taken for reducing the power consumption;

[0049] FIG. 5 shows exemplary screen content including messages displayed on the screen in accordance with the present method;

[0050] FIG. 6 exemplarily shows the power consumption of an exemplary TV set for various mains supply voltage levels;

[0051] FIG. 6b exemplarily shows the power consumption of an exemplary TV set for various mains supply voltage levels in accordance with an embodiment of the present method;

[0052] FIG. 7 shows an exemplary power consumption profile for an exemplary TV set with voltage hysteresis between enabling and cancelling power consumption reduction modes;

[0053] FIG. 8 exemplarily shows the mains supply voltage and mode switching of an exemplary media stream reproducing device in accordance with the present method over time for an exemplary brown-out event; and

[0054] FIG. 9 shows a basic exemplary flow diagram of the present method.

[0055] In the figures, identical or similar elements are referenced using the same reference numerals or reference symbols.

DETAILED DESCRIPTION OF EMBODIMENTS

[0056] FIG. 1 shows a basic, exemplary block diagram of a media stream receiver 100 having a display 102 suitable for implementing the present method or one or more embodiments and/or developments thereof. Media stream receiver 100 includes a power supply 104, analog and digital tuners 106, 108 and their respective signal processing 112, e.g. demodulation, demultiplexing and/or decoding. Decoding in this exemplary embodiment is performed in accordance with one of the MPEG standards. Once demodulated, demultiplexed and/or decoded the received signal is subjected to further signal processing 114, e.g. in a digital signal processor under control of a microprocessor. The processed signal is fed to display 102 and/or to an audio system 116, for outputting an image on display 102 and sound through loudspeakers 118. Media stream receiver 100 further includes a power supervisor 122 for detecting a brownout condition on the power supply line.

[0057] FIG. 2a shows a first exemplary power supply circuit 200 with a primary side voltage supervisor circuit having a primary side microcontroller 202. Microcontroller 202 samples input voltage B+ present on input capacitor C1 downstream of bridge rectifier B1. Resistors R1 and R2 divide input voltage B+ to a level suitable for an ND-converter input (not shown) of primary side micro controller 202. The sampled value is transferred to a secondary side of power supply 200 by optocoupler 204 and is fed to main microprocessor 206. Main microprocessor 206 runs software instructions for evaluating the transferred value and for taking actions in dependence of the value. The actual conversion from the mains voltage into the secondary voltage or voltages is provided by converter 212.

[0058] FIG. 2b shows a second exemplary power supply circuit 200 with a primary side voltage supervisor circuit. This exemplary circuit uses an additional rectifier D1 and a capacitor C2 for sampling the input voltage. Capacitor C2 has a much lower capacitance than capacitor C1 and allows for a more accurate measurement with a faster response. The voltage across capacitor C2 follows the input voltage much faster than B+ on capacitor C1 which has a larger capacitance. As in the exemplary circuit of FIG. 2a the voltage is divided by resistive divider comprising resistors R1, R2. The voltage across resistor R2 is tapped off by a series-connection of Zener diode ZD1 and a forward-biased diode of optocoupler 204. Resistor R1 limits the current through the series-connection. Whenever the voltage across resistor R2 is larger than the Zener voltage of Zener diode ZD1 plus the forward voltage of the optocoupler's diode a signal corresponding to the current through the series-connection is transferred to the secondary side by optocoupler 204. An output transistor of the optocoupler 204 translates the signal into a current from a secondary-side supply voltage through resistor R3 to ground. The current causes a voltage drop across resistor R3, which is sampled by an AD-converter (not shown) of main microcontroller 206. Like in FIG. 2a the actual conversion from the mains voltage into the secondary voltage or voltages is provided by converter 212.

[0059] FIG. 3 shows a further exemplary power supply circuit 200 with a primary side voltage supervisor circuit that is a combination of the circuits of FIGS. 2a and 2b. Like in FIG. 2a the voltage B+ across capacitor C1 is fed to microcontroller 202 via a resistive divider comprising resistors R3 and R4. In addition, a rectifier B2 rectifies the mains voltage and supplies the rectified mains voltage to capacitor C2, which has a smaller capacitance than capacitor C1. As mentioned further above, the mains voltage is typically constant over long time period but can have spikes and sags of relative short duration. Disturbances within a cycle of the mains AC voltage are filtered by the capacitor C1 and are not considered a brown-out. However, rectifier B2 and capacitor C2 are designed to be able to measure the momentary AC mains voltage, and to provide a corresponding value to microcontroller 202 via a resistive divider comprising resistors R1 and R2. In this exemplary power supply the momentary AC mains voltage and B+ are effectively measured. The voltage value measured at C2 is a representation of the momentary mains voltage, which can be used for a quick reaction of the system to beginning anomalies of the AC voltage, and the voltage at C1 represents the voltage available for the power supply for the next few seconds. Microcontroller 202 controls optocoupler 204 to transfer a signal representative of the mains power supply condition to main microcontroller 206, which eventually initiates one or more power consumption reduction measures as appropriate. Like in FIGS. 2a and 2b the actual conversion from the mains voltage into the secondary voltage or voltages is provided by converter 212.

[0060] As discussed further above the energy saving concept implemented by the present method may have different reaction times for different energy saving measures. An automatic detection of a brown out must be capable of distinguishing between different stages of a brown out.

[0061] For avoiding a complete blackout a quick reaction, e.g. by entering a first level of power saving, is advantageous. Such quick immediate power saving by e.g. 10 million TV sets, or generally media stream reproducing devices, each reducing the power consumption by e.g. 50 W within a few milliseconds would reduce the load on the mains power grid by 500 MW, allowing for the grid to stabilize and recover. If such quick energy saving, without really losing the ability of comfortably watching TV, was not sufficient a further power reduction by gradually further reducing the power consumption begins. As the brown-out progresses further, further steps of power saving are triggered, as will be discussed in detail below with reference to FIGS. 6 and 6b.

[0062] Dramatic steps are only accepted by the user if he/she receives clear information about the actions taken and the reasons, as will be discussed in detail below with reference to FIG. 5. The information may comprise one or more of a simple voltage level displayed, a brown-out warning by text or speech output, information about precautions taken or planned by the TV-system, and a text or spoken guideline for further useful contributions in response to the power shortage.

[0063] FIG. 4 shows an exemplary graphic representation of various mains power supply voltages and respective actions taken for reducing the power consumption. At nominal level, 230 V in this example, the media stream reproducing device operates normally, i.e. brightness, picture improvements and audio volume are reproduced as set by the user. The normal operation mode is valid within the upper and lower tolerances of the nominal mains power voltage. In the example of FIG. 4 the normal operation is maintained even at a voltage level that is 15% lower than the nominal mains voltage level. In a mains voltage level range between 85% and 80% of the nominal mains voltage level a first power reduction mode is enabled. In this example the luminance, i.e. the display brightness, and the audio volume are reduced. In a mains voltage level range between 80% and 75% of the nominal mains voltage level a second power reduction mode is enabled. In this example the display brightness and the audio level are set to a minimum value the media stream reproducing device is capable of. In case the mains voltage is within a range of 75% and 65% of the nominal mains voltage level a third power reduction mode is enabled. In this example the media stream reproducing device will reproduce only the audio of the media stream. If the mains voltage level falls below 65% of the nominal mains voltage level an indication is provided to the user and the device is subsequently shut down.

[0064] In embodiments of the present method whenever a new power saving level is enabled corresponding information is provided to the user, e.g. via the display or any other suitable indicator. Such information may include information about the actual input voltage level and the respective power saving level. As discussed further above, as soon as the voltage level recovers, the media stream reproducing device will enable a power saving mode involving a smaller reduction of the power consumption. A hysteresis and/or a delay function may be provided for suppressing quick toggling between two modes.

[0065] The reduction in power consumption when reducing only the audio volume is comparatively small when compared to the possible reduction when changing picture settings such as brightness. Changing audio settings will allow for a reduction in the range of 3-10 W. Most of the power is consumed by a subwoofer speaker, if provided. Hence, turning off the subwoofer only, for power saving is a conceivable option.

[0066] A typical 60 inch LCD-TV consumes, at minimum brightness, around 45 W, while still producing a clearly visible image, and up to 150 W at the highest brightness. Normal power consumption is about 90 W. Operating the same TV in an audio-only mode, i.e. backlight completely turned off, will consume around 25 W. The remaining power is mostly due to receiver and other processing blocks still being powered. A sophisticated design will allow the power consumption in the audio only mode to be reduced to around 10 W by inactivating all unnecessary picture processing blocks.

[0067] Table 1 provides an exemplary overview over various levels of power consumption and savings for various power saving modes enabled at different mains voltage levels.

TABLE-US-00001 TABLE 1 exemplary power savings Input Power voltage saving (nominal Mode- Power (nominal 230 V) level action consumption 90 W) 100-85%  0 Normal TV 90 W 0 85-80% 1 reduced background 60 W 30 W illumination 80-75% 2 Minimum 45 W 45 W background illumination, no graphical effects 75-65% 3 Audio mode/ 5-10 W   80-85 W   emergency services below 50% 4 TV off (Standby) <1 W 89 W

[0068] In an embodiment the present method provides information about the brownout to the viewer via the display screen. The information may be present permanently or for a limited time when a transition to a different power saving mode takes place.

[0069] FIG. 5 shows exemplary screen content including messages displayed on the screen, e.g. using an on-screen-display module, or OSD module, provided in the media stream reproducing device. The messages inform the user about a beginning or present brownout. Some messages may provide text information about the measures initiated or soon to be initiated by the media reproducing device for reducing the power consumption. E.g., the message may inform about reduced brightness or audio only mode. Likewise, the message may include additional information such as current mains supply voltage level, either in Volts or as a percentage of the nominal voltage, e.g. ‘mains is at 85%’. Also, the message could ask the user to take other actions in order to reduce the household's power consumption in the household, e.g. ‘Please turn off unused devices’.

[0070] The message may also be accompanied by a selection menu offering power reduction actions for the media stream reproducing device. For example, the exemplary screen shot in the middle image of the left column in FIG. 5 displays a choice for the user to turn the TV off, to record the present movie or to keep watching TV, though possibly at a reduced brightness.

[0071] As previously discussed the power reduction is not limited to a single step. A typical TV set will work, without any restrictions, down to 85% of the nominal input voltage and only then gradually reduce the power consumption by enabling one or more of the above mentioned power consumption reduction measures. It may be advantageous to reduce, in a first step, the power consumption to an acceptable level, e.g. level 1 of Table 1, only to be followed by a gradual further lowering of the power consumption, eventually arriving at an operating mode that represents the lowest power consumption that still allows for watching TV. Further reduction modes, including an audio only mode discussed further above will be enabled if the mains supply voltage drops further. FIG. 6 exemplarily shows the power consumption of an exemplary TV set for various mains supply voltage levels. It is to be noted that the curves may include some hysteresis and/or delay between entering a power reduction mode and cancelling such mode, returning to a higher power mode. Delays provided for enabling power reduction modes may be in the range of seconds, and delays for returning to a higher power mode or normal operation may be about 10-1000 times longer. The delays may be different for different severities and durations of a brown out. In FIG. 6 the lowest power consumption that is not standby is provided by a recording mode, assuming that a recording device consumes less power than a display or an audio reproduction of the streamed media content.

[0072] FIG. 6b shows a similar power consumption profile for various mains supply levels for an exemplary TV set as FIG. 6. However, when in standby a receiver of the media stream reproducing device remains on for receiving weather alerts, e.g. storm warnings as provided by the US NOAA.

[0073] FIG. 7 shows an exemplary power consumption profile for an exemplary TV set with voltage hysteresis between enabling and cancelling power consumption reduction modes. The arrows indicate the course of actions taken with the variation of the mains supply voltage.

[0074] FIG. 8 exemplarily shows the mains supply voltage and mode switching of an exemplary media stream reproducing device in accordance with the present method over time for an exemplary brown-out event. From T0 to T1 the mains supply voltage is nominal, or within the corresponding tolerances, and the media stream reproducing device is in normal operation mode. In between T1 and T2 the mains supply voltage drops significantly due to a brown-out. An immediate reaction of the attached media stream reproducing device is switching to a lower power mode, e.g. resulting in a power consumption reduction of 50%. Between T2 and T3 the mains supply voltage drops further and the media stream reproducing device gradually further reduces the power consumption to minimum power consumption, e.g. with backlight set to minimum when reaching T3. However, between T3 and T4 the mains supply voltage continues to fall but the backlight illumination or brightness cannot be reduced any further. Thus, the further drop of the mains supply voltage between T4 and T5 below a value triggers the next power reduction step, e.g. turning off the display and operation in audio-only mode. In this mode audio-visual content is played only via the speakers and, depending on the capabilities of the media stream reproducing device, is recorded for later viewing. At T5 a weather alert appears, e.g. transmitted via auxiliary data in the media transport stream. This alert must be displayed for security reasons. Thus, between T5 and T6, without the distributed wakeup feature of the present method, invention all media stream reproducing devices would immediately switch to a higher power level, for indicating the warning to the users. However, using one embodiment of the distributed wakeup feature of the present method, wakeup of individual media stream reproducing devices is delayed by different time periods, and the media stream reproducing devices are turned on in a time-distributed fashion such that a surge power-peak is considerably reduced. In an alternative embodiment a randomly delayed indicator signal is provided to different, individual media stream reproducing devices, and each media stream reproducing device will turn on for a short time period, reproducing the message, but not all of the devices will turn on at the same time.

[0075] The power consumption for time intervals T5 to T9 is not represented for a single media stream reproducing device. Rather, two alternatives are shown. The solid line indicates the accumulated power consumption using the distributed wakeup feature of the present method. The dotted line indicates the accumulated power consumption without using the distributed wakeup feature of the present method. The patterned background depicts the range of a random time period for each single media stream reproducing device to turn on or for cancelling a power reduction mode.

[0076] From T6 to T7 the mains supply voltage remains below a value and the media stream reproducing devices remain in the low power consumption mode entered before, e.g. audio-only mode or standby.

[0077] At T7 the mains supply voltage returns to nominal value, either gradually or in a step-like manner. At this time period the media stream reproducing devices shall return to normal operation. The dotted line shows a steep increase in the total power consumption that results from all media stream reproducing devices returning to normal operation essentially simultaneously, which could result in overloading the grid, possibly triggering a new brown-out. However, T7 to T11 is also a time period during which individual media stream reproducing devices return to normal operation or to an operation mode with less reduced power consumption than before in a time distributed manner. Thus, in accordance with the present invention, from T7 to T8 a random delay similar to the interval T5-T6 is used for avoiding all media stream reproducing devices turning on at the same time. In the time interval T8 to T9 a slow rise of the overall power consumption is shown. This slow rise is the sum of all media stream reproducing devices turning to normal operation at randomly different times. In a development of the present method, in the time interval between T9 and T10 the media stream reproducing devices are kept at an average illuminating level for another random time period, allowing for the mains power grid to further stabilize. During this interval the user can watch media streams without major restrictions. Then, in the time interval from T10 to T11 the media stream reproducing devices return to individual, normal operating conditions, each after a third random time period has expired.

[0078] It is to be noted that the time intervals T7 to T11 are not necessarily four independent random time intervals. A single time period T7 to T11 is likewise conceivable for solving the return-from-power-reduction problem, e.g. by providing different distribution functions for the switching-on of different functionalities in different individual media stream reproducing devices.

[0079] FIG. 9 shows a basic exemplary flow diagram of the present method. At step 800 the media stream is received. At step 802 the mains supply voltage is detected. When the mains supply voltage remains above a first level, no-branch of decision step 804, the receiving and monitoring is continued in a normal manner. When the mains supply is below the first level, yes-branch of decision step 804, a message is output to the user, step 806, and receiving and monitoring is continued. Alternatively or in addition, step 808, a signal is output for controlling the media stream reproduction device in accordance with one or more embodiments or developments of the method described in this specification, and receiving and monitoring is continued. Yet alternatively or in addition, step 810, the received media stream is recorded, and receiving and monitoring is continued. For simplicity reasons various voltage levels for triggering individual ones of the power reduction measures are not shown in the figure. Likewise, time delays or averaging of measurements are not shown. However, these variations are easily implemented in basic structure of the method as presented herein and form part of embodiments or developments of the present method.