Heatron|Electrical Lighting Capabilities from Heatron

Overview

Providing power in the most efficient manner is critical to high power luminaire performance and lifetime. Knowing how to regulate electrical current to maximize brightness while maintaining longevity is a balancing act that can't be overlooked if you expect to successfully promote your product to the general market.  Heatron has the experience and talent needed to ensure that your LED fixture performs well and lasts as you say it will.

Design Process

• Understand customer needs/requirements
• Develop concept with Heatron engineering input
• Choose topology and select reference design
• Create BOM and develop customer proposal
• After acceptance of proposal and order placement, build prototype
• Test/evaluate prototype, get agency approvals
• Preproduction and production runs

SPICE® Modeling

• SPICE® Modeling is a process of creating a virtual model of the driver circuit and LEDs using computer software.
• The computer software used for this is ORCAD®.
• The model is used for scenario building; that is, for testing various circuit iterations and predicting which produce the most efficient driver/LED combination.
• For switching power supplies and other circuit designs, it allows frequency/filtering analysis .
• SPICE® Modeling reduces time and cost because a virtual circuit is built and tested rather than physically needing to breadboard the circuit to determine actual performance.
• After the model is optimized, physical prototypes are tested to confirm final performance.

Off-Shelf vs. Custom

• Custom drivers
  • Allow tailored functions (dimming, CCT control, etc) that differentiate the end product in its market.
  • Typically have higher efficiency
  • Can be design to optimize cooling
  • Designed to fit within customer's housing
• Off-Shelf drivers
  • Quick delivery (speed to market)
  • More economical if production quantity is small

AC / DC

• 120 to 277 VAC needs to be converted to current regulated DC at low voltages for driving LEDs
• There are several common topologies:
  • Cuk
  • Flyback
  • Push Pull
• Design Considerations:
  • Efficiency
  • Cost
  • Power factor correction
  • EnergyStar Compliance, Title 24, etc.
  • Agency compliance testing
  • (UL, EC, FCC, etc.)
  • Thermal management considerations
•   Functional configuration for a AC/DC driver
  

DC / DC

• Sometimes AC/DC power conversion is not required but DC to DC is. For example: solar, transportation, portable lighting or other off-line applications
• Two broad categories of DC to DC Converters:
  • Linear
    • Lower cost
    • No emission concerns
    • Not always efficient
    • Produces heat from wasted power
  • Switchers
    • Highly efficient
    • Minimal wasted power
    • Minimal heat production
• Design considerations for DC/DC are efficiency, cost, thermal management, agency requirements

Off-Shelf Integration

• Combine off-shelf driver with appropriate current regulating circuitry
  • Lower development cost because AC to DC with agency approvals is done
  • Current regulating circuitry provides stable and consistent power to LEDs
  • Faster speed to market
  • Features not available with off-shelf driver only can be incorporated (PWM dimming, CCT control, etc.

PWM

• The best and only appropriate method to dim LEDs
• No shift in color temperature or hue
• Drops power to LED efficiently with minimal wasted power
• Cool running because it's efficient
• Flexible because there are many integrated solutions and design options.

Occupancy Sensors

• Occupancy sensors will become more common place as awareness for energy savings grows
• EnergyStar® and other green standards will require use of occupany sensors
• Often it will be more efficient to build this feature into a driver than have as a separate add-on
• Heatron is developing compliant products which will be available in the near future

Energy Star®

Heatron supports the work and standards of the DOE EnergyStar® and CALiPER programs.  Because the LED fixture market has grown so quickly there were no standard methods for testing and evaluating fixture performance.  As a result, the performance claims of some LED products were overstated leading to disappointment and distrust of the end user.  The DOE programs provide a basis for uniform and objective measurement of LED fixture performance and a means of sample testing fixtures offered to the broad market, thus instilling confidence in the end user when making a buying decision.

• Heatron is able to design and produce lighting fixtures that meet EnergyStar® requirements.
• The DOE EnergyStar® Solid State Lighting program went into effect on September 12, 2008. 
• Additional fixture categories are being added in 2009 by the DOE including LED replacement lamps
• Along with EnergyStar®, two supporting test procedures have been finalized: LM-79 which describes how to measure LED fixture light output, and LM-80 which describes how to measure lumen depreciation.

Visit http://www.energystar.gov/ for more information.