Scouts soldering badge lvl. 2

Care must be taken when applying heat to solder the battery holder. Too much heat can damage artwork on the other side. Not enough heat will not fix the part properly and will come off when (or after) instering the battery cell.

Cautions:

- Cell batteries are EXTREMELY dangerous if swallowed.

- Soldering tools can cause burns if not correctly used

- Protection goggles must be worn during soldering

- Soldering fume extractor with filter is adviseable to be used.

BOM:

- PCB: download gerber file from Project Attachment section below and use it to order the PCB at JLCPCB or any supplier of choice. 

- 3mm red led with flasher IC

- 220Kohm or 300Kohm resistor - resistor value is "tuning" sensing sensitivity.

- 2N3904 transistor with bent legs footprint (wider footprint for easier soldering) (see variants in datasheet: 2N3904(TO-92).pdf (octopart.com))

- LTR-4206E phototransistor (datasheet: Datasheet for LTR-4206E Lite-On Phototransistor | Octopart

- CR2032 surface fitted battery holder (datasheet: BAT-HLD-001-xx-OTL_C_180723 (octopart.com))

- CR3032 battery cell - some of the cheap CR2032 are not working probably because their internal resistance is huge. For example, IKEA CR2032 do not work but some no-name cells I bought from Amazon do. Try before you buy large quantities.