Thursday, January 19, 2017

Floodlamp technology marches on

In our home we have lots of 3-1/2-inch diameter R30 floodlamps mounted on sockets recessed in the ceiling. (There are six in the kitchen, and four in the living room). When we moved in there were 65W incandescent lamps. Three years ago we replaced those with 15W warm-white compact fluorescent lamps. The fluorescent lamps started slowly and were not dimmable.

At the Boise Costco store on January 11th I saw some 8-packs of 9.5W dimmable R30 daylight LED floodlamps (as shown above)  that normally were $26.99 but had a $16 rebate. I bought one package. The final price including sales tax was just $1.46 per lamp. These LED lamps are instant-on and seem brighter, although their output actually is rated at 650 lumens versus the 750 lumens for the compact fluorescents. Later I bought two more packs for the halls and master bedroom.

Quality control on the LED lamps wasn’t wonderful. On one the threaded end broke away from the body when I tried to screw it into a kitchen ceiling socket (with my suction-cup-on-a-broomstick light bulb changer). So, I got out a ladder and removed the body by hand. Then I used a needle nose pliers to unscrew the threaded end that still was lodged in the socket. I could see a power supply circuit board inside the lamp body, so I got out a hacksaw and pliers and dissected the failed lamp.

Near the front there are seven LEDs (yellow rectangles) on a circuit board held by four tabs onto an aluminum reflector. At the center is a two-pin socket where the power supply circuit board plugs in.

Here is a top view of the circuit board.

Here is a bottom view of that circuit board, with more surface-mounted components which include 9 capacitors (C), 4 diodes (D), 2 inductors (L), and 17 resistors (R).   

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