High temperature LED system using an AC power source
View Patent ↗Power management and thermal management for high intensity LED lamps are disclosed.
1. An LED system for coupling to an AC power source comprising:
a rectifier module being electrically coupled to the AC power source, the rectifier module being configured to provide a rectified output;
a first array of LED devices, the first array of LED devices being electrically coupled to the rectifier module and to receive the rectified output;
a second array of LED devices electrically coupled to the first array of LED devices;
a current monitor module electrically coupled to the first array and second array of LED devices, the current monitor module being configured to determine a first current level using a drawn current level signal associated with the first array of LED devices and a second current level using a reference current level signal associated with the second array of LED devices; and
a signal compensating module electrically coupled to the current monitor module, the signal compensating module being configured to generate a first compensation factor signal based on a difference between the first current level and a first reference current level.
2. The system of claim 1 further comprising a low pass filter electrically coupled to the current monitor module and the signal compensating module.
3. The system of claim 1 wherein the first array of LED devices is electrically coupled to the second array of LED devices in series.
4. The system of claim 1 further comprising a first switch and a second switch, the first switch being configured to control the first array of LED devices in response to the compensation factor signal.
5. The system of claim 1 wherein the signal compensating module comprises a divider module.
6. The system of claim 1 wherein the signal compensating module comprises a differential operational amplifier.
7. The system of claim 1 wherein the rectifier module is mounted to a printed circuit board.
8. The system of claim 1 , further comprising:
an LED submount having a front surface and a back surface, the front surface comprising an inner region and an outer region, the inner region being characterized by a reflectivity of at least 80%, the first and second arrays of LED devices being disposed on the inner region.
9. The system of claim 8 wherein the first and second array of LED devices are configured for being operable at 100 degrees Celsius or higher.
10. The system of claim 8 further comprising:
a heat sink directly coupled to the back surface of the LED submount, the heat sink being characterized by a thermal emissivity of at least 0.5.
11. The system of claim 10 wherein the outer region of the heat sink is substantially non-reflective.
12. The system of claim 10 further comprising an MR-16 housing.
13. The system of claim 10 wherein the outer region of the heat sink is coated with anodized aluminum material and characterized by a thermal emissivity of at least 0.8.
14. The system of claim 10 wherein the heat sink is coated by a non-reflective material, a surface of the heat sink being characterized by an emissivity of at least 0.9.
15. The system of claim 10 wherein at least 10% of the front surface area is characterized an emissivity of 0.6 or greater.
16. The system of claim 10 further comprising a reflector positioned within an inner region of the front surface.
17. The system of claim 10 wherein a thermal resistance from the LED submount to the high-emissivity surface area is less than 8 C/W.
18. The system of claim 10 wherein the outer surface of the heat sink is coated by a substantially black coating.
19. An LED system for coupling to an AC power source comprising:
a rectifier module being electrically coupled to the AC power source, the rectifier module being configured to provide a rectified output;
a first array of LED devices, the first array of LED devices being electrically coupled to the rectifier module and to receive the rectified output;
a second array of LED devices electrically coupled to the first array of LED devices;
a current monitor module electrically coupled to the first array and second array of LED devices, the current monitor module being configured to determine a first current level using a drawn current level signal associated with the first array of LED devices and a second current level using a reference current level signal associated with the second array of LED devices;
a signal compensating module electrically coupled to the current monitor module, the signal compensating module being configured to generate a first compensation factor signal based on a difference between the first current level and a first reference current level; and
an LED submount having a front surface and a back surface, the front surface comprising an inner region and an outer region, the inner region being characterized by a reflectivity of at least 80%.
20. An LED system for coupling to an AC power source comprising:
a rectifier module being electrically coupled to the AC power source, the rectifier module being configured to provide a rectified output;
a first array of LED devices, the first array of LED devices being electrically coupled to the rectifier module and to receive the rectified output;
a second array of LED devices electrically coupled to the first array of LED devices;
a current monitor module electrically coupled to the first array and second array of LED devices, the current monitor module being configured to determine a first current level using a drawn current level signal associated with the first array of LED devices and a second current level using a reference current level signal associated with the second array of LED devices;
a signal compensating module electrically coupled to the current monitor module, the signal compensating module being configured to generate a first compensation factor signal based on a difference between the first current level and a first reference current level;
an LED submount having a front surface and a back surface, the front surface comprising an inner region and an outer region, the inner region being characterized by a reflectivity of at least 80% the first and second arrays of LED devices being disposed on the inner region; and
a heat sink coupled to at the LED submount the heat sink being characterized by a thermal emissivity of at least 0.5.