FreeTrack Forum
|
Hi benmeijer
I dont want to Hijack your Thread but just to have a better impression how your idea can look like, I build this little sweat thing. The final connection to the Battery is missing. I did this in just 2,5h including collecting all the stuff in my place. The Cap I use, my first build, took me round about 1 day to build. Pros - Very easy to build - Very light without Batteries - Easy switching LED´s Cons - Power source - Batteries put heavy weight to one side of your head (put some Batteries to the other side of your Head to balance  )But for Beginners this is pretty perfect, because you can tweak your Setup very easy. If you think about an alternative Power Source you can use a Power Supply or use a USB Cable (NOT FOR BEGINNERS!!!!!) But remember, if you switch your Power Source you have to use other Resistors!!!!!! And some Pictures    I hope this Pictures will make this Thread sticky  Very well Done! |
|
|
I started this topic because some people don't understand diagrams like these:
 and there's a issue with the long leg of the SFH485P is negative. I wanted to show how simple it can be. Oh ... and when you put your batteries on top of your head there's almost no problem with the weight / or balance! See my build: http://forum.free-track.net/index.php?showtopic=466&page=4#8487. Soon I will made "a easy build setup using 5v power from the computer ...." ! |
|
|
Great post benmeijer!
I don't now the least bit about electronics but with these instructions I think I might be able to pull it off  I have one question though: can this design be modified to use a single resistor in the battery box, before the wire is split off in 3 branches? If so what components would be required? Many thanks, Schermvlieger |
|
|
Thanks guys!
I'll pay a visit to the local electronics shop with the parts list from this post /edit Jay it works great! Thanks again benmeijer! |
|
|
New scheme for serial build using 5V USB power:
 new uploaded picture, tinypic had removed original 7 feb 2011 edit 1: (If you use other type of leds, (not SFH485P) the shorter leg is almost negative ! check your datasheet) edit 2: aug. 2010 Updated picture with more specific info (old picture here: http://i36.tinypic.com/25zsge8.jpg) If you use a PTC, take in consideration that this component has some initial resistance (3- 5 ohm). If you want 50 mA - subtract this inititial value from the 10 ohm (my advice: use the 6.8 ohm!). for a example, see my latest construction:  fullsize pics here (post #105): http://forum.free-track.net/index.php?showtopic=466&message=12613 |
|
|
Hi, yesterday I tought about your first setup and wondered about pros and cons of serial vs paralel and came with such serial circuit modification:
Pros: + 1/3 of current in circuit then in paralel setup -> 3 time more battery life (actualy 1,5 times per battery since it uses 4 batteries) + Easier soldering - only 1wire on 1 wire vs 3 wires on 1 in paralel, saves space and resistors (though they are cheap). Cons: -1.2V too low so only nonrechargable batteries *At 30mA with 2400mAh batteries, it should work 80 hours! (48h on 50mA). *Can be used with 6V AC/DC stabilised source, if batteries are not prefered. *In upgraded version, it is possible to adjust brightness by switching resistors (trough connectors).  This is my first plan for LED tracking device and I have not much experince in electronics, but I hope have it right. BTW as I checked resistor values according to Ohm law, LEDs seem to be counted as 50 Ohm resistance added (-> Serial: 6V/(50R+3*50R)=0.030A or Parallel: 2.4V/(30R+50R)=0.030A), am I right? I have cam that is easy to IR mod + floppy VIS filter. According to HW FAQ, 30mA should be OK. Whats your experince with brightness setups (day/night), since I see only 40+mA's here? I was also thinking on clip/cap construction since i prefer to have something that would be as light as possible (batteries would be on table) and possibly independent on audio headset. Then I saw thick rubber-coated wire and got idea:  If it looks confusing, look at this headset and you 'll get the idea: http://info.vltavastores.cz/ceniky/imagesSE/normal/205807.jpg Good thing is that it is easy to wrap it around head for maximum ergonomy and its incredibly light. I plan to create the velcro plate from modelling plastic, then harden it by boiling. I plan to make the track clip similar way using the wire and modelling plastic. It would connect by velcro -> could be attached to various other headsets. EDIT: I successfuly created it, now posted in Your point model constructions thread. |
|
|
I think if you're using 3 leds, 30 mA each, you consume 90 mA. And the resistor also consumes current. I'm not an electrician so maybe I'm wrong.
I like your idea of a variable resistor, but maybe you can use a potentiometer (http://en.wikipedia.org/wiki/Potentiometer) ? 22 ohm + var 0-30 ohm. I have no problems with brightness (at day / night) because I'm using a Wiimote .... that is a IR cam. I power my leds 50 - 75 mA. Maybe it will work with 30 mA .... Try it, and let us know. I also had thoughts to make my setup with thick rubber-coated wire, but could not find the perfect material. What will you use? I made my plates from (plastic):   |
|
|
Class : Apprenti Off line |
Hi benmeijer!! Please, let me know why your scheme is different of the wizard?? Calculating by LED Assembly Wizard setup they show: Power supply- 5v Forward current- 75mA Forward voltage- 1,5 RESISTOR = 27Ohms Why you get 10 Ohms?!?!? thanx! |
){kind=link}
> Stats
1 user(s) connected during the last 10 minutes (0 member(s) and 1 guest(s)).