These badges were designed as a soldering demo for the Rhode Island Computer Museum (RICM). They were designed to teach the basics of thru-hole soldering, as well as to provide users with a take home wearable.
- A beginner kit for learning to solder.
- A simple circuit, 2 LEDS and a battery, but still interactive.
- Low cost, suitable for scout troops, school classes, summer camps, etc. Depending on order volume, parts will cost $2-4 per badge.
- Solder the battery clip onto the exposed pads on the back of the board. Note that the battery clip used in this design is surface mount and considerably more difficult to solder than the other components. Depending on the audience it may be desirable for the instructor to solder this component before passing them out.
- Flip the board over and solder all other components to the front. Resistor values and transistor orientation are printed on the silkscreen.
- Insert battery into clip and turn on switch. Hold hand over photoresistor to light up LEDS
1x printed circuit board. 1x 47KΩ resistor (1/4W 5% carbon-film) 2x 220Ω resistors (1/4W 5% carbon-film) 1x NPN transistor (2N3904 or similar NPN (BC547,2N2222 etc.), TO-92-3 Kinked Lead) 2x light-emitting diodes (5mm, any color as desired) 1x SPDT mini slide switch (Shouhan SS-12D07VG3 or similar) 1x battery holder (Keystone 3002, 20mm coin cell, surface mount) 1x CR2032 Battery (3V, 20x3.2mm, 200mA)