MCUs in E-Bikes: driving lights, LED/LCD display and measurements

This article explores design techniques and challenges for implementing an electronic bike (E-Bike) built using a microcontroller or Programmable System on Chip (PSoC). Current E-Bike systems use a microcontroller with external signal conditioning and comparator circuitry to drive the three-phase motor; external ADC and external amplifiers for different sensor inputs; relay driver circuitry for brake … Read more

Remote phosphor expands reach of LED light

The 100-year reign of the incandescent light bulb will endin 2012 as the Energy Independence and Security Act of2007 mandates the phase-out of most incandescent bulbsin favor of more efficacious forms of lighting. New formsof lighting will also need to meet consumers’ expectationsfor light color, dimming performance, lifetime, and the light patternthat a bulb casts. … Read more

Super Bowl XLVII blackout: Power redundancy, paralleling and LED lighting

Image courtesy of Mario Sanchez, AP No, Beyoncé’s revival of Destiny's Child did not cause the blackout during this year’s Super Bowl game on February 3, 2013. It was  combination of technical and communication failures that contributed to the partial power outage according to an independent analysis. Dr. John Palmer of Palmer Engineering & Forensics … Read more

LED-current limiter accepts ac or dc

LED drivers have lots of featuresand require plenty of externalcomponents. When your applicationrequires no PWM (pulse-width-modulated)dimming or controlled frequencyoperation, your primary concern may bethat too much current could damage ordestroy your LEDs. In this case, you canmake a simple LED-current limiter froma common low-dropout linear regulator.The circuit in Figure 1 is an LED lightbulb for … Read more

Linear and switcher LED supplies combine, overcome disadvantages of each topology

To control their brightness, LEDsneed a constant current; this canbe done with a resistor placed in serieswith the LED string. Both the LED-stringvoltage and the supply voltagecan vary, so a dedicated LED driver is amust to guarantee the current accuracy.Two solutions—each with advantagesand disadvantages—are widely used: alinear constant-current LED driveror a step-down switching converter. Linear … Read more

Five things to know about EMF requirements for lighting products

The IEC (International Electrotechnical Commission)Technical committee TC 34 (lamps and related equipment) published the standard IEC 62493 Edition 1 (Assessment of lighting equipment related to human exposure to electromagnetic fields) in December 2009. Its European counterpart, EN 62493, was published by Cenelec in 2010. As the standard deals with safety aspects, it was also published … Read more