The shipping from Newark was $9, parts were $11something! arrgh
Total price for the boards and components
$27.99
If you choose check it out and tell me what you think (I got it so I can teach my kids electronics and soldering and get them into techy stuff...one kid took to coding like it was something he always did)
You can use those AA batteries that have discharged so much they won't run anything...but now you have more or less "emergency lighting" besides your big honkering flashlights ;)
I have no input, but this is a very cool concept to teach your kids and seems like a great way to teach it. Many times I have wanted to have a joule thief available to power something with batteries. Being able to make my own would have been very helpful. Best wishes on a successful outcome.
But these pull way past the .9vdc cutoff, and can drive those simple LED's that put out enough light to see by...not Cree level light but more than enough to find your way around...on batteries that won't run anything else
Can't wait...seems Newark in IL is frozen in and haven't shipped any of my other components I ordered either...dangit!
Joule thiefs are fun and all, but like half of the batts I used them on ended up leaking. Draining alkies all the way can cause some of them to outgas and rupture. It’s something to keep in mind.
V1.1 fixed and running great https://oshpark.com/shared_projects/Pv0rRfN6
Turns out he used an old version of Eagle CAD and on the parsing of the .brd file at OSHPark it dropped a few of the traces, he went back and corrected it and now V1.1 works awesome...in the mean time I did a bit of trace fixing on my boards that were missing traces...and VIOLA, at .9vdc running a 14kcd 5mm LED just as bright as a full charge 1.5vdc battery, these things are quite bright and provide more than enough light to see and get around if there was no other light source available
My trace fix
Sorry my soldering is horrible because I had to redo them about 4x times!
And shots of it running
All parts except box and jumper push button Digi-Key
1 3 BCAAPC-ND HOLDER BATTERY AA PLASTIC PC MNT 3 0 0.92000 $2.76
2 6 CF14JT1K00CT-ND RES 1K OHM 1/4W 5% CARBON FILM 6 0 0.08000 $0.48
3 3 CF14JT2K20CT-ND RES 2.2K OHM 1/4W 5% CARBON FILM 3 0 0.08000 $0.24
4 3 1285PH-ND CAP CER 470PF 1KV 10% RADIAL 3 0 0.24000 $0.72
5 3 493-12814-1-ND CAP ALUM 100UF 100V 20% RADIAL 3 0 0.43000 $1.29
6 3 811-1312-ND INDUCTOR RADIAL 470UH 0.60A 3 0 1.42000 $4.26
7 6 BC548BU-ND TRANSISTOR NPN 30V 100MA TO-92 6 0 0.21000 $1.26
Subtotal $11.01 (for 3x complete sets)
