28 November 2009

Flashing Light

    Idea of this device came to me as a result of conversation with my neighbor and friend. He had told me about journey on his boat. The boat size is about 15 meters. He usually makes cruises for several days. During these days he fishes, relaxes and makes a fun on the river or on the beach. And just one trouble happens with him during journeys.

By the floating rules on top of the the boats must be set a light. And this light must light up during nights.

    Placed accumulator discharges very fast. So he forced to use energy very economically. And even this measure does not help. At the morning of the second day accumulator fully discharges. He asks me about using solar cells for recharging. But that solution after first calculation had been expensive. Another way is to use more accumulators. But I didn't liked it. Because in that case needed to prepare not one but two or three vehicle size accumulators before journey. This mean you must recharge them all and place on the boat before journey.

So I have designed for him this flashing LED light. The main idea is to use not constant but flashing light. Big duty cycle reduces power consumption about 20 times.

   Another feature is to use bright LEDs. Today LEDs are most effective lighting devices on the market. For used Amber LED efficacy of lighting with driver and heating looses included is about 47 lm/W. For comparison most effective halogen lamps give 28 lm per watt.

   Some simple drawing of mechanical is made in picture below. There is 3 cutoff boards placed on sides of equilateral triangle. This arrangement provides circular lighting. The LEDs attached to the boards through the hole in the center. Extra caution must be taken during bringing together boards. To avoid shorted circuit and not provided connections.

   In this link you can find bill of materials of Flashing Light.