Analysis the challenges of LED lamp design and replace the existing lighting II

 Size is the key factors restricting the replacement scheme, while the thermal limits are often more critical. LED only the emission of visible light, etc under cabinet led light, waterproof led strip light, r7s led bulb. and other technical differences, they do not produce infrared radiation energy. Therefore, white LED than incandescent or halogen lamps more energy-efficient, the vast majority of heat through the light conductor dissipation.

Heat dissipation is restricting the lamp can generate light key factors, present in the lighting products used in LED technology is difficult to achieve the mainstream market can accept the brightness level. In order to break through the brightness limit, need to solve the problem of heat dissipation, this product is also successfully commercialized essential condition.

Heat is also a direct impact on the driver board service life. To emit a higher intensity, lamp must operate at relatively high temperatures ( +80° C to +100 °C ). This temperature, the drive plate life will limit the lamp work, especially electrolytic capacitor has become the design face a difficult problem. Because the electrolytic capacitor at high temperatures will soon dry, in such conditions, the capacitance of the working life of no more than thousands of hours, this has become restricts the entire service life of the lighting lamp factors. Long service life is LED lights one of the main selling points, designers, relatively short life of electrolytic capacitor design as the main barrier.

Maxim for 120VAC\/230VAC input and 12VAC input replacement lamp launched a unique LED driving scheme. These LED driving scheme can save the circuit board of the electrolytic capacitor, so that the LED lamp life from the usual less than 10000 hours to 90000 hours. Due to the elimination of electrolytic capacitor, also help to narrow program size, the driving plate to be mounted to a small size replacement lamp frame.

Compatible to the electrical infrastructure

LED replacement lamp must in the existing infrastructure work, including cut angle ( three triac and delayed ) dimmer and electronic transformer.

Access to 120VAC\/230VAC power supply, lighting firstly three triac dimmer control. The three end of the triac dimmer design is able to coordinate well with incandescent lamps and halogen lamps, these lamps are pure resistance load. However, the use of LED transform lamp, LED drives are typically nonlinear, non pure resistance load, input bridge rectifier is usually in the AC input voltage is positive and negative peak transient absorption current. Three triac dimmers can not guarantee LED of this demand, because it can not provide the required start-up current, cannot provide a holding current. Thus the dimmer does not start or when working normally closed, but it will also cause flashing LED, this is also the system cannot accept the phenomenon.

As a replacement, its electrical architecture more in line with the 12VAC input lighting design, because the electronic transformer and the dimmer can be connected to the lamp input. However, the 12VAC input lamp drive is used in conventional rectifier bridge and a DC-DC converter topology, because the transformer and dimmer incompatibility, will also produce scintillation.

Maxim 120VAC\/230VAC and 12VAC input lighting solutions using single level transformation.

The input current shaping, can make the lighting in the lighting States will not flicker occurs, these programs compatible with the two-way controllable silicon and the three end of the dimmer and electronic transformer design. At present, not a MR16 scheme has the characteristic, rarely have the PAR, R and A type light scheme has the characteristics of. In addition, our solution is better than 0.9 power factor correction, requires minimal external components. Without electrolytic capacitor, the capacitor under the environment of high temperature will seriously restrict the work of driving circuit. 120VAC\/230VAC and 12VAC solutions are used in MAX16834IC, available for users to * estimation and put into mass production. These are the unique Maxim scheme, Maxim is only able to provide the advantages of combination of suppliers.