Emergency power supply unit and method for operating an emergency lighting means

1. An emergency power supply unit (A) for operating an emergency light ( 6 ), comprising at least one LED, the emergency power supply unit (A) comprising:

an energy storage unit ( 2 ) configured to provide a battery supply voltage (V Bat ) in case of a mains voltage supply loss, wherein the emergency power supply unit (a) detects a battery supply voltage value;

and

a controlling unit ( 5 ) configured to control the operation of the emergency power supply unit (A) based on the actually monitored battery supply voltage (V Bat ) value;

wherein in a first operating mode of the emergency power supply unit (A), an emergency light ( 6 ) is switched-on;

wherein in a second operating mode of the emergency power supply unit (A), the controlling unit ( 5 ) is operative and the emergency light ( 6 ) is switched-off; and

wherein in a third operating mode, the battery supply voltage (V Bat ) is galvanically isolated from the controlling unit ( 5 ) by a switching means ( 11 ).

2. The emergency power supply unit (A) according to claim 1 , wherein the first operating mode is activated if the detected battery supply voltage (V Bat ) is above a first threshold voltage.

3. The emergency power supply unit (A) according to claim 2 , wherein the third operating mode is activated if the detected battery supply voltage (V Bat ) falls below a second threshold voltage that is below the first threshold voltage value.

4. The emergency power supply unit (A) according to claim 1 , wherein the second operating mode is activated if the detected battery supply voltage (V Bat ) falls below a first threshold voltage or an activation command is received by the controlling unit ( 5 ).

5. The emergency power supply unit (A) according to claim 1 , wherein the third operating mode is activated if a timeout-command provided by a timer-unit is received by the controlling unit ( 5 ).

6. The emergency power supply unit (A) according to claim 1 , wherein power consumption in the second operating mode is at least ten times higher than in the third operating mode.

7. The emergency power supply unit (A) according to claim 1 , wherein the controlling unit ( 5 ) is configured to determine the mains voltage supply loss and wherein after the determination of the mains voltage supply loss the energy storage unit ( 2 ) is configured to provide the battery supply voltage (V Bat ).

8. The emergency power supply unit (A) according to claim 1 , wherein the energy storage unit ( 2 ) is a battery, wherein the battery is rechargeable with a mains voltage supply ( 1 ).

9. The emergency power supply unit (A) according to claim 1 , wherein a transition from the third operating mode into the first operating mode is triggered by a mains voltage reset.

10. The emergency power supply unit (A) according to claim 1 , wherein the controlling unit ( 5 ) is configured to drive another light.

11. The emergency power supply unit (A) according to claim 1 , wherein the supply unit (A) further comprises a driving unit ( 4 ) for driving the emergency light ( 6 ), wherein the driving unit ( 4 ) is controlled by the controlling unit ( 5 ).

12. A method for operating an emergency light ( 6 ), comprising at least one LED, by means of an emergency power supply unit (A), wherein the method comprises the following method steps:

providing a battery supply voltage (V bat ) in case of a mains voltage loss;

monitoring the battery supply voltage (V Bat ) value; and

controlling the operation of the emergency power supply unit (A) based on the actual battery supply voltage (V Bat ) value;

wherein in a first operating mode of the emergency power supply unit (A), the emergency light ( 6 ) is switched-on;

wherein in a second operating mode of the emergency power supply unit (A), the emergency power supply unit (A) is non-operative and the emergency light ( 6 ) is switched-off; and

wherein in a third operating mode, the battery supply voltage (V Bat ) is galvanically isolated from the controlling unit ( 5 ) by a switching means ( 11 ).

13. The method according to claim 12 , wherein the first operating mode is activated by the controlling unit ( 5 ) upon receiving of an operation command through a DALI compliant interface.

14. The method according to claim 12 , wherein the first operating mode is activated by the controlling unit ( 5 ) upon detecting that the battery supply voltage (V Bat ) is above a first threshold voltage.

15. The method according to claim 12 , wherein a transition from the third operating mode to the first operating mode is triggered by a mains voltage reset.

16. An emergency power supply unit (A) for operating an emergency light ( 6 ), comprising at least one LED, the emergency power supply unit (A) comprising:

an energy storage unit ( 2 ) for providing a first voltage (VBat) of a first voltage value; and

a voltage converting unit ( 8 ) which is configured to convert the first voltage (VBat) into a voltage value higher than the first voltage value, for operating the light ( 6 );

wherein:

the emergency power supply unit (A) comprises a control unit ( 5 ), wherein the control unit ( 5 ) is supplied by a second voltage (VDD) with a second voltage value;

the emergency power supply unit (A) comprises a driving unit ( 4 ) for driving the light ( 6 ), wherein the driving unit ( 4 ) is supplied by a third voltage (VCC) with a third voltage value; and

the voltage converting unit ( 8 ) converts the first voltage (VBat) in dependence on a control signal ( 50 ) of the control unit ( 5 ) to a voltage value higher than the second voltage value or equal to the third voltage value.

17. The emergency power supply unit (A) according to claim 16 , wherein the control signal ( 50 ) is switched in accordance with an operation command, which is received at the control unit ( 5 ).

18. The emergency power supply unit (A) according to claim 16 , wherein the third voltage value is higher than the second voltage value and wherein the voltage converting unit ( 8 ) is either configured to:

convert the first voltage (VBat) into a voltage equal to or higher than the third voltage value; or

convert the first voltage (VBat) into a voltage value in between the second voltage value and the third voltage value.

19. The emergency power supply unit (A) according to claim 16 , wherein the control unit ( 5 ) is configured to receive operation commands through a DALI compliant interface; and wherein upon receiving a first operation command, the control signal ( 50 ) is switched to a first control signal value; and wherein upon receiving a second operation command the control signal ( 50 ) is switched to a second control signal value.

20. The emergency power supply unit (A) according to claim 19 , wherein the first operation command is a REST-mode command and wherein the voltage converting unit ( 8 ) converts the first voltage (VBat) into a voltage with a voltage value lower than the third voltage value and higher than the second voltage value.

21. The emergency power supply unit (A) according to claim 19 , wherein upon receiving the first operation command, the current drain from the energy storage unit ( 2 ) does not exceed a predetermined current value.

22. The emergency power supply unit (A) according to claim 19 , wherein the second operation command is a Re-light command according to a lighting standard (DALI) and wherein the voltage converting unit ( 8 ) converts the first voltage (VBat) into a voltage with a voltage value equal or higher than the third voltage value.

23. The emergency power supply unit (A) according to claim 16 , wherein the control unit ( 5 ) is configured to drive a second light.

24. The emergency power supply unit (A) according to claim 16 , wherein the control unit ( 5 ) is configured to obtain automatic testing commands via a DALI-interface ( 7 ).

25. The emergency power supply unit (A) according to claim 16 , wherein the energy storage unit ( 2 ) is a battery, wherein the battery is rechargeable with a main voltage supply ( 1 ).

26. The emergency power supply unit (A) according to claim 16 , wherein the control unit ( 5 ) is configured to determine a main voltage supply loss and wherein after the determination of the main voltage supply loss the energy storage unit ( 2 ) is configured to provide the first voltage (VBat) with the first voltage value.