Teardown of novel glass 1.6W LED lamp with flat COB filament.

Описание: This lamp is much better than I was expecting. It's based on the newer style of LED filament lamps but uses a piece of glass as a substrate for a large series array of LEDs. There are actually 28 LEDs wired in series and they are driven by a fairly conventional (but not perfect) capacitive dropper supply. The DC is smoothed by a capacitor, but the LEDs are directly across the capacitor with no current limiting, so they tend to ride the top of the sinewave a bit. It's not terribly visible to the naked eye though. The LEDs are run at about 20mA and I have to say I'd rather they were run at 15mA or so for longevity. The lamps stated rating is 1.2 to 1.6W (probably according to the supply voltage) and the current is determined by the value of the capacitor. Changing the 390nF capacitor for a 330nF or even 220nF one would bring the current down a bit, but still give a good bright visual effect.

The glass has the LEDs on one side, but a layer of phosphor on both sides to catch as much of the blue light as possible and convert it to white light. However, there is a noticeable area of blue-white emitted by the sides.

I'd love to see these filament/COB (chip on board) style lamps with coloured LEDs. I'd guess it's only a matter of time until that happens.

This light used a plastic base with an exterior metal shell and base stud for the lampholder connection. the plastic section was crimped into the metal outer shell, and the glass globe itself was siliconed into the plastic.