Shared Projects by Heisenbug

$17 for 3 break-apart boards, each containing gun (narrow strip) and target (larger).

IR arcade shooter gun + target w/prototyping space, needed since the designs come with 2 totally different flavors of target…Grrr.
The Makezine project’s article online says one thing, but the project designs on the author’s site show something entirely different. Since I planned to make the boards with flexibility built-in already (for other unrelated future prototyping & experimentation), I decided to also make it easy to cut traces around the IC socket on the back of the target board and arbitrarily rewire things if needed (probably so.) The rear silkscreen makes it more apparent if cuts have been made, as well as highlighting the cut lines.

Muttering to self about the stupidity of having coexisting proprietary and open designs…

Clearly, both schematic design and board layout are untested, but they should at least work for experimentation/prototyping.

$5.35 / set of 3; but you can now get the new smaller version here for $4.50

Designed more for vertical use, e.g. right-angle 9pin header plugged into a breadboard.

DS1337s on top, Supercap (I chose 1.5F) and 78L05 (SOIC version 5-volt regulator) on bottom, and one or a pair of [low-Vf] diodes makes for a batteryless clock module that will happily keep time with monthly charging, on anything from 7~18v [using regulator] or can be run direct on 1.8-5v.

Don’t forget to install the jumper-wire, and charge session[s] should total 24-48 hours per month for better results with high-ESR supercaps.

The regulator can also power other small circuitry; just keep in mind power dissipation and current rating (~1W or 100mA).

Uploaded [originally] 10/20/2014 21:42.

$6.80 gives you R-boards enough for 6 flashlights, so why not share them?
If this design is too small, try my newer version.

A high-tech twist for the cheap 9LED flashlights - cut off one of these round boards and surface-mount 2 15ohm resistors in the slots, remove the stock 3xAAA holder from the flashlight (use it elsewhere, like for an arduino or something) and use a Lithium-Ion 18500 cell instead! Then add this populated R-board between the back end (-) of the battery/cell and the switch/tailcap spring.
The only other part to add is some craft foam to wrap around the cell for cushioning, approximately 1/16 - 3/32 inch thick. Done!

The resistance added on this board prevents the Li-Ion cell from frying the LEDs with too much current, and 15ohm/2 (=7.5) conveniently approximates 20mA for each of the LEDs (total ~175mA max at full charge) so they’ll last nearly forever without burning out…but given the cheap construction of these flashlights, you may still need to remove the LED board somewhere down the road to mend/improve the edge-mount solder connections if it starts to flicker.

Be sure to get Li-Ions with protection boards built in, as you probably don’t want a fire in your pocket should anything happen to go wrong. I got protected cells and have had no trouble at all.

Assembly: 1 x 15ohm 1/4W resistor in each slot with leads bent to opposite sides of the board, ignoring the thru-holes for them. Solder down to exposed traces, building a center spiral on one side (to contact the back (-) of the cell), and keeping the center clear on the other side for the tailcap spring. Tin the center of the pad where the spring rests, though.

Bugs:
* The break-apart didn’t work - the cut-outs did not come through for me and it’s one solid board.
* Aside from the cut-outs not working out (and I discovered an explanation why), nothing to go wrong, except in assembly.
* I’ll update with images.
* Solder mask not laid out for the “center spiral” idea (front/back sides not differentiated), some scraping may be needed. YMMV.
* This design, at ~0.75", was too small to seat solidly in my flashlight and while it works, it also will slide around when the tailcap is removed. The fixed version for this cutout-fail is also increased to about 0.9" diameter to make a much tighter fit, but will need edge smoothing and rounding once broken apart.

A shrunken clone!
$23.90/set of 3, untested but fully expected to work.

Minus FTDI-style add-on serial module (fits in “docking bay” next to DC jack, can be RS-232, using max232, or USB, using FT232RL)
RS-232 module to be added eventually…

$8.95 for 3 copies & works even if you just get “close” to the values specified here. Tested as solder practice for students.

I’m aware this IC seems to be Not Recommended for New Designs… or at least the DIP version of it. But try to find another speaker amp of 1-2W with an idle current draw in the single-digit mA range, and operates between 2-9v (or more) - I’ve yet to find another one that does all that.

Parts: [source suggestions to come]
2 small electrolytics, 4.7uF 16+v
5 large electrolytics, 470uF 6.3-16v (the one far right, above the output, can be any large size greater than the supply voltage)
4 non-polarized caps 0.1uF SMD
6 pT/H (thru-hole) resistors, 2x each of 4.7ohm, 10Kohm, and 3.3Kohm, 1/4W
LED and 4k7 SMD resistor optional - or even short the R-pads and use a 2-pin header with an LED+resistor combo cable
0.1" 3-pin headers for audio in & out, 2x3 header for off-board volume pot, and reversible 4-pin header for power in - you choose gender for all of them.
TDA2822 DIP or SOIC-8 amp IC (note DIP has higher max power rating, 1.4W total - check amazon for batches of 5-20pcs.) …Another equivalent chip is NJM2073, made by NJR/JRC (digikey’s mfg. page) as a pin-for-pin replacement.
I designed for both DIP-8 and SOIC-8 packages, so there would be no need for an SOIC adapter board when trying to assemble this project.

Mounting holes on 3 of 4 corners, grounded, spaced 1.5" long by 0.8" wide.
The last board design I uploaded/shared before I learned how to use the “smash” tool in EagleCAD. Separating the labels from the package can be a great thing if you need to move the labels in tight spaces. This design ought to be evidence enough for that fact, though I didn’t feel that improving the labels alone would warrant a re-upload.
If my labels here leave you confused, you might check out my first version, which is less visually cluttered since I left off many of the labels altogether.