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DayHawk: 365nm "Black Light" Surveyor

This project builds a high-fidelity 365nm Ultraviolet (UVA) searchlight. Unlike the purple-tinted “395nm” toys, true 365nm light is nearly invisible until it hits a reactive surface, making it the perfect tool for biological and mineralogical surveys.

Safety Warning (Serious Caw!)

:!: UV Radiation Hazard: 365nm is high-energy UVA. Because your eyes cannot “see” the beam, your pupils will not contract, allowing high-energy photons to hit your retina full-force.

Item Part Number Description Est. Price (CAD) Note
The Shield 3M Virtua CCS Polycarbonate Safety Glasses ~$8.00 Mandatory. Polycarbonate naturally blocks 99.9% of UV.
Alternative Honeywell A700 Clear Anti-Scratch UV Lens ~$6.50 Cheap insurance for your retinas.

* Do not stare at the beam. * Wear your shields. Even clear polycarbonate blocks the UV spectrum.

The Glow: Bio-Survey

In the Pacific Northwest, the DayHawk will make the following “pop” out of the darkness:

  • Lichen & Fungi: Many local tree lichens (like *Lobaria*) and mushrooms fluoresce in vivid oranges and yellows.
  • Millipedes (Xystodesmidae): Look for the “Yellow-spotted millipede.” Many of these glow a ghostly neon yellow/green under 365nm.
  • Moths & Pollinators: Many local moths have wing patterns meant to be seen in the UV spectrum by other insects.
  • Spider Silk: Certain orb-weaver silks glow bright white or blue, revealing complex webs in the brush.

Fluorescent Rocks & Minerals

Common findables that react to 365nm:

  • Sodalite / “Yooperlites”: Often found in riverbeds or coastal gravel; glows a brilliant, fiery orange.
  • Wernerite (Scapolite): Primarily found in Quebec but traded locally; emits one of the brightest “canary yellow” glows in the mineral kingdom.
  • Calcite & Agate: Many local quartz and calcite veins will glow ghostly white, green, or pale pink depending on the impurities.

Other Notable Finds

  • Scorpions & Insects: While scorpions (bright aquamarine) are rare in BC, many local Crab Spiders and Caterpillars (like Hornworms) glow neon green/yellow.
  • Biological Traces: Animal urine (including rodents/pets) glows bright yellow-white, making it an essential tool for tracking or cleaning.
  • Vitamins & Chemicals: Tonic water (Quinine) glows blue; Vitamin B12 glows bright yellow; Antifreeze glows “nuclear” green.

The Shiny Bits (BOM)

Item Part Number Description Unit Cost (CAD) Note
The Source CUN66A1G Seoul Viosys Z5 (367nm) $8.42 The Powerhouse. 1.4A Max.
The Filter ZWB2 Glass “Wood's Glass” Filter $4.00 Crucial. Blocks visible purple.
The Star 104990051 3535 Copper DTP Star $3.50 Copper DTP required for UV heat.
The Brain LD06AJSA Adj. Constant Current $5.00 Must limit to 1.0A max.
The Juice INR18650-30Q Samsung 30Q 18650 Li-ion $12.40 3000mAh. High drain cell.
The Lens 20mm-38mm Quartz/Glass Lens $8.00 No plastic optics!
The Talon KSC241J LFS IP67 Tactile Switch (SMT) $0.80 Tiny, waterproof, and very durable.

Total Est. Cost per Unit: ~$42.12 CAD. (~$29.72 if you can reuse a lipo cell battery.)

<comment> Note: This total assumes you are reusing an 18650 battery and host from a donor light. If buying new, add ~$20.00 for a Samsung 30Q and a Convoy S2+ host. </comment>

The Circuit (1.0A Current Limit)

To protect the Seoul Viosys chip, we use a 1.8k Ohm safety resistor to cap the driver at 1000mA (1A).

[ CIRCUIT: THE DAYHAWK ]

             ( + ) Li-ion 18650 Battery
               |
      +--------+----------+
      |                   |
      |                [SWITCH] 
      |                   |
      |         +---------v---------+
      |         |     [ CE / EN ]   |
      +-------[VIN+]    LD06AJSA    |
                |     LED DRIVER    |
      +-------[VIN-]                |
      |         |    [ ISET PAD  ]--+
      |         |    [     |     ]  |
      |         |    [1.8k Safety]  |
      |         |    [     |     ]  |
      |         |    [ 1k POT    ]--+ 
      |         |                   |
      |         |  [LED+]   [LED-]  |
      |         +----+-------+------+
      |              |       |
      |            ( A )   ( K )
      |            [  UV LED  ]
      |                 |
      +-----------------+

Crow's Comments

  • Lichen Hunting: If you're surveying in the Vancouver area, head to a damp park like Stanley Park or Pacific Spirit. The variety of lichen that glows is staggering!
  • Invisible Heat: Like the Void-Eye IR project, this light feels “dim” but is outputting significant energy. If the head of the DayHawk gets hot, your heatsinking is working.
  • The Filter Test: If you can see a purple beam hitting the wall, you need a thicker ZWB2 filter. A perfect 365nm beam should be almost invisible until it hits something fluorescent.

Caw! Keep your eyes shielded and your minerals glowing!

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