LED A19 Bulb 60 W for $2.49


It requires 8.5 W for a 60 W equivalent at 800 Lumens A19 bulb.

The new bulb weighs around 49 g total, the old bulb heat sink alone is 70 g so for the same input power to the bulb, the heat sink is smaller and there is no potting around the driver. The number of LEDs went from 18 to 11 with the lumen output almost double.It is not measure the LED voltage on the old string, but it measured over the 60 V SELV limit on the new bulb as safety is now achieved from the mechanical housing not through electrical isolation from the driver.  Therefore, it’s obvious that lower weight, less LED counts, better materials or materials that function good enough can all contribute to lower cost. The driver is more interesting.  The old driver was an isolated flyback design.   The new driver has a smaller EMI filter and even the transformer is smaller. The BOM count was 53 or so in the past versus 27 or so today – this will reduce cost and improve reliability in the driver. Clearly, the trend is to reduce the driver electronics besides the material changes and efficiency of LEDs.

So where are drivers for LED bulbs going next? 

Integration: but there are discrete designs that use the low cost components without the need for an integrated analog controller that provides good enough performance. NPN transistors in place of MOSFET transistors, better EMI filtering, fuses part of the printed circuit board, etc.

Non-isolated designs: when thinking about this trend and reducing component count the idea of Direct AC LED topologies can reduce the component count further and possibly eliminate some of the lower reliability electrolytic capacitors. But how do these observations enable a smart LED solution?  Lighting is evolving from something used to see or read, but is becoming a user experience: warm dimming, color tuning, communication to control, visible light communication to guide us, sensors that interpret implicit human movement or environment changes, etc.  The latest low cost LED Bulb is a pathway to enable the technologies to take lighting into the future by reducing not just cost, but by pushing the boundaries on how we think about the construction of the bulb and how we challenge conventional thinking about consumer electronic design.

Source: Ledjournal

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