Light Flicker Analyzer

 After the problem I had with an LED sewing machine light flickering, I decided to build a lighting flicker analyzer. I built an adapter to connect a solar panel to my oscilloscope, which allows me to see a live display of the light level vs time.  

Light Flicker Analyzer

First, I tested the mostly dark room. It was noisy with no pattern. Next, I tested the old incandescent bulb. It had a mostly smooth pattern with a very low amplitude wave.

Incandescent bulb

Next, I tested the E12 LED sewing machine bulb. The difference was quite dramatic. It showed a pulse about every 9ms (60 Hz). This explains why my photos of the sewing machine had dark stripes- the light is flashing. It's barely visible to the human eye but obvious when I took a picture.

Flickering LED

Photo of flickering light

Finally, I tested the new LED bulb from IKEA. It isn't designed to go in sewing machines (too large to fit easily and almost too bright), so I tested it in an old candelabra light. The oscilloscope results look almost identical to the incandescent bulb. The wave is very smooth and barely noticeable on the graph. This means it probably has capacitors and a better control board.

IKEA LED bulb