External assessment device for a lighting system and method of assessing a lighting system

1. An assessment device for a lighting system, wherein the assessment device comprises:

an input terminal which corresponds to an output terminal of a driver;

an output terminal which corresponds to an input terminal of a light engine;

a voltage regulator configured to provide power to a microcontroller,

wherein the microcontroller is configured to sample an LED+ line voltage and an LED− line voltage with respect to a ground; and

wherein the assessment device is independent of the driver and the light engine;

and wherein the assessment device further comprises a memory configured to store a zero-state LED+ line voltage and a zero-state LED− line voltage therein;

wherein the microcontroller is configured to sample the LED+ line voltage and the LED− line voltage with respect to ground a second time after a predetermined amount of time; wherein the microcontroller is configured to extract a sample mean of the voltages and a maximal difference of the voltages; and wherein the microcontroller is configured to compare the sample mean of the voltages and the maximal difference of the voltages to the zero-state voltages.

2. The assessment device of claim 1 further comprising a voltage divider in parallel with the voltage regulator.

3. The assessment device of claim 2 wherein the voltage divider is configured to obtain through a first analog to digital converter information about the electric potential of the LED+ line and the ground.

4. The assessment device of claim 2 , the microcontroller further comprising a second analog to digital converter, wherein the second analog to digital converter measures a potential difference between the LED− line and the ground.

5. The assessment device of claim 1 , wherein the assessment device is configured as a pluggable module.

6. The assessment device of claim 1 , further comprising a dimming portion, wherein the dimming portion comprises a digital to analog converter with a control portion.

7. The assessment device of claim 6 , wherein the control portion is configured to be connected to a control interface of the driver.

8. A method for assessing the condition of a light engine and a driver for the light engine using an assessment device, the method comprising:

connecting the assessment device to the driver in a zero-state, wherein the assessment device comprises:

an input terminal which corresponds to an output terminal of the driver;

an output terminal which corresponds to an input terminal of the light engine;

a voltage regulator configured to provide power to a microcontroller,

wherein the microcontroller is configured to sample an LED+ line voltage and an LED− line voltage with respect to a ground;

entering an acquisition state in which the driver is in the zero-state wherein the microcontroller initiates a burst and samples the voltages on an LED+ line and an LED− line with respect to the ground;

storing a zero-state LED+ line voltage and a zero-state LED− line voltage in a local non-volatile memory;

reentering the acquisition state after a predetermined amount of time;

extracting a sample mean of the voltages and a maximal difference of the voltages;

comparing the sample mean of the voltages and the maximal difference of the voltages to the zero-state voltages.

9. The method of claim 8 , wherein the acquisition state comprises:

entering a time interrupted state wherein the microcontroller initiates a signal sample burst of fast analog-to-digital conversion in which the voltages on the LED+ line and the LED− line are sampled with respect to ground.

10. The method of claim 8 , further comprising averaging the maximal difference with other maximal differences collected in a determined time period to obtain a maximal difference average.

11. The method of claim 10 , further comprising combining the maximal difference average with the zero-state LED+ line voltage and the zero-state LED− line voltage.

12. The method of claim 11 , further comprising estimating a remaining useful life of the driver.

13. The method of claim 8 , further comprising periodically measuring the average forward voltage and current of the light engine to obtain at a plurality of light engine values; and

storing the light engine values in the non-volatile memory.

14. The method of claim 13 , further comprising comparing the measured light engine values and determining the condition of the light engine.

15. The method of claim 8 , further comprising:

turning on the light engine;

reaching a desired forward current by performing a predetermined number of voltage step; and

measuring a Voltage-Current (VI) curve of the light engine.

16. The method of claim 15 , further comprising storing a plurality of VI curves in the non-volatile memory.

17. The method of claim 16 , further comprising comparing VI curves to determine a condition of the light engine.

18. A lighting system comprising:

a light engine;

a driver for operating the light engine;

an assessment device independent of the driver, the assessment device comprising:

an input terminal which corresponds to an output terminal of the driver;

an output terminal which corresponds to an input terminal of the light engine;

a voltage regulator configured to provide power to a microcontroller,

wherein the microcontroller is configured to sample an LED+ line voltage and an LED− line voltage with respect to a ground; and

wherein the assessment device is independent from the driver and the light engine; and wherein the assessment device further comprises a memory configured to store a zero-state LED+ line voltage and a zero-state LED− line voltage therein; wherein the microcontroller is configured to sample the LED+ line voltage and the LED− line voltage with respect to ground a second time after a predetermined amount of time; wherein the microcontroller is configured to extract a sample mean of the voltages and a maximal difference of the voltages; and wherein the microcontroller is configured to compare the sample mean of the voltages and the maximal difference of the voltages to the zero-state voltages.