Uploaded July 2017 | Updated September 2026, 2 weeks ago
After seeing fellow Youtuber VWestlife's entry for this contest, I decided to see what one could come up with a bunch of "junk drawer" stuff. Amazingly, it worked for the required length of time (and then some, since I let it run for a few minutes so as to get the speed right prior to starting the five minute run).
2020 update: as quickly as it came along, the Flashing Light Prize project and web site seem to have faded away. Videos like this one, and a few forum posts are all that's left now. There were at least one or two more contests after this one, but they were much more restrictive in what you could do and how.
Hindsight being what it is, I think a swinging needle (analog) voltmeter would have looked so much cooler than the digital one attached to the light bulb.
This consists of a box fan saved from the scrap heap, a manila paper tag I found attached to a used UPS, a variable autotransformer ("Variac"), some aluminum foil, a bent up slot blank from a scrapped computer, an incandescent flashlight bulb in a reflector assembly, a screw and a six volt rechargeable lantern battery.
As the fan blades go by, they graze the foil covered paper tag, which is connected to one terminal on the battery. The slot blank is attached to the load. When the two touch, a circuit is completed. Duty cycle is controlled by how fast the fan blades turn, which is governed by where the variable autotransformer is set.
After seeing fellow Youtuber VWestlife's entry for this contest, I decided to see what one could come up with a bunch of "junk drawer" stuff. Amazingly, it worked for the required length of time (and then some, since I let it run for a few minutes so as to get the speed right prior to starting the five minute run).
2020 update: as quickly as it came along, the Flashing Light Prize project and web site seem to have faded away. Videos like this one, and a few forum posts are all that's left now. There were at least one or two more contests after this one, but they were much more restrictive in what you could do and how.
Hindsight being what it is, I think a swinging needle (analog) voltmeter would have looked so much cooler than the digital one attached to the light bulb.
This consists of a box fan saved from the scrap heap, a manila paper tag I found attached to a used UPS, a variable autotransformer ("Variac"), some aluminum foil, a bent up slot blank from a scrapped computer, an incandescent flashlight bulb in a reflector assembly, a screw and a six volt rechargeable lantern battery.
As the fan blades go by, they graze the foil covered paper tag, which is connected to one terminal on the battery. The slot blank is attached to the load. When the two touch, a circuit is completed. Duty cycle is controlled by how fast the fan blades turn, which is governed by where the variable autotransformer is set.
