I needed to make 15 simple circuits with a light, battery and switch that could be easily assembled and disassembled multiple times for a Cub Scout camp activity. The light need to be bright enough to be visible in direct sunlight (working outside). And they needed to be as cheap as possible.
The prices, parts and sources were the cheapest I found for ordering enough for 16. I ordered 1 extra because it was cheaper then needing to order a replacement later if a piece was lost or failed due to shipping costs. The batteries are the only thing that didn’t come as individuals, but ordering significantly more or less of these may result in another source being cheaper.
16x RL5-BR2020: Super Bright (4000 mcd) 5mm Blinking Red LED - $ 0.54 ea - $11.85
16x SPST10: SPST on-off Miniature Toggle Switch - $0.60 ea - $13.60
2x Lithium 3V Batteries Size CR2032 (Pack of 25) - $3.95 ea - $7.41
10ft Solid copper 18 gauge door bell wire (two wires) - $0.23 ft - $2.53
Electrical tape (on hand)
Solder (on hand)
Hot glue (on hand)
Scrap wood (on hand)
Total price: $35.39 (with shipping, tax, etc.) or $2.35 each (with one set of spare parts)
Some of the pictures are upside down. They appear the correct orientation on my Mac as it reads the orientation information from the camera but provides no convenient way to rotate images like Windows 7. Sorry about that.
And here is one circuit blinking: