fungus wrote:> On Jul 26, 8:57 am, ehsjr <eh...@NOSPAMverizon.net> wrote: > >>I don't _know_ if it qualifies as "a whole lot" better, but >>available one chip solutions can meet the op's stated requirement >>of keeping the current at 15-20 mA, and the joule thief cannot. >> > > > Can you maybe recommend one...?Manufacturer chips posted below are just the first few found by a Google search with "led boost drivers" in the search box. National recommends their LM3410X for this. http://www.national.com/ds/LM/LM3410.pdf TI shows the TPS61160 meeting the requirements. http://focus.ti.com/lit/ds/symlink/tps61161a.pdf Onsemi has the CAT3606-D http://www.onsemi.com/pub_link/Collateral/CAT3606-D.PDF Linear's LT3598 will do it: http://cds.linear.com/docs/Datasheet/3598fa.pdf I'm not recommending any one of those over any other, and there are other chips from those manufactures and others that may suit your needs. Ed
Joule Thief - still not working....
Started by ●July 23, 2009
Reply by ●July 26, 20092009-07-26
Reply by ●July 26, 20092009-07-26
On Sun, 26 Jul 2009 17:06:24 GMT, ehsjr <ehsjr@NOSPAMverizon.net> wrote:>fungus wrote: >> On Jul 26, 8:57 am, ehsjr <eh...@NOSPAMverizon.net> wrote: >> >>>I don't _know_ if it qualifies as "a whole lot" better, but >>>available one chip solutions can meet the op's stated requirement >>>of keeping the current at 15-20 mA, and the joule thief cannot. >> >> Can you maybe recommend one...? > >Manufacturer chips posted below are just the first few found by a >Google search with "led boost drivers" in the search box. > >National recommends their LM3410X for this. >http://www.national.com/ds/LM/LM3410.pdf$2.50-$3 each. Lots around.>TI shows the TPS61160 meeting the requirements. >http://focus.ti.com/lit/ds/symlink/tps61161a.pdfHmm. Cheaper. $2 each. Lots around.>Onsemi has the CAT3606-D >http://www.onsemi.com/pub_link/Collateral/CAT3606-D.PDFCouldn't find the -D around anywhere. But did find CAT3606HV4-T2 at Digikey for $1 (and at only two other places.) This device cannot handle more than 4.2V input and must have at least 3V. It's designed for Li-ion sources and can run in either 1X or 1.5X mode. I'm not hyped on this as a 'solution.' It's a charge pump with regulation on the current, I think.>Linear's LT3598 will do it: >http://cds.linear.com/docs/Datasheet/3598fa.pdfMucho expensive. I found them for over $7 each! (Some at under $5, too.) Only a few places carry them. .... TI seems to be the one out of the above I'd focus more on. Looks nice and seems to do the right job for a reasonable price and is at various stores, as well. Jon>I'm not recommending any one of those over any other, >and there are other chips from those manufactures and >others that may suit your needs. > >Ed
Reply by ●July 26, 20092009-07-26
On Jul 26, 6:18=A0pm, Ecnerwal <MyNameForw...@ReplaceWithMyVices.Com.invalid> wrote:> > Supertex CL2Datasheet says 5V minimum input voltage...
Reply by ●July 26, 20092009-07-26
On Jul 26, 7:51=A0pm, Jon Kirwan <j...@infinitefactors.org> wrote:> >National recommends their LM3410X for this. > >http://www.national.com/ds/LM/LM3410.pdf > > $2.50-$3 each. =A0Lots around. > > >TI shows the TPS61160 meeting the requirements. > >http://focus.ti.com/lit/ds/symlink/tps61161a.pdf > > Hmm. =A0Cheaper. =A0$2 each. =A0Lots around. >Maybe there's lots where you live but I don't know where I'd get one around here, and there's none on eBay. But ... while I was trawling eBay I found a lot of people selling LM3914s. It's a dedicated LED driver chip, can work with 3V input and drive up to 10 LEDs with programmable current (up to 30mA each). http://www.national.com/mpf/LM/LM3914.html Even better: It has an input sensor making LED bar graphs. I assume I could just pull the sensor high to turn on all the LEDs but it opens up lots of fun possibilities - eg. I might be able to make the LEDs respond to sound, which would be very cool for processions. Almost seems too good to be true ...
Reply by ●July 26, 20092009-07-26
On Sun, 26 Jul 2009 17:51:59 GMT, Jon Kirwan <jonk@infinitefactors.org> wrote:>On Sun, 26 Jul 2009 17:06:24 GMT, ehsjr <ehsjr@NOSPAMverizon.net> >wrote: > >>fungus wrote: >>> On Jul 26, 8:57 am, ehsjr <eh...@NOSPAMverizon.net> wrote: >>> >>>>I don't _know_ if it qualifies as "a whole lot" better, but >>>>available one chip solutions can meet the op's stated requirement >>>>of keeping the current at 15-20 mA, and the joule thief cannot. >>> >>> Can you maybe recommend one...? >> >>Manufacturer chips posted below are just the first few found by a >>Google search with "led boost drivers" in the search box. >> >>National recommends their LM3410X for this. >>http://www.national.com/ds/LM/LM3410.pdf > >$2.50-$3 each. Lots around. > >>TI shows the TPS61160 meeting the requirements. >>http://focus.ti.com/lit/ds/symlink/tps61161a.pdf > >Hmm. Cheaper. $2 each. Lots around. > >>Onsemi has the CAT3606-D >>http://www.onsemi.com/pub_link/Collateral/CAT3606-D.PDF > >Couldn't find the -D around anywhere. But did find CAT3606HV4-T2 at >Digikey for $1 (and at only two other places.) This device cannot >handle more than 4.2V input and must have at least 3V. It's designed >for Li-ion sources and can run in either 1X or 1.5X mode. I'm not >hyped on this as a 'solution.' It's a charge pump with regulation on >the current, I think. > >>Linear's LT3598 will do it: >>http://cds.linear.com/docs/Datasheet/3598fa.pdf > >Mucho expensive. I found them for over $7 each! (Some at under $5, >too.) Only a few places carry them. > >.... > >TI seems to be the one out of the above I'd focus more on. Looks nice >and seems to do the right job for a reasonable price and is at various >stores, as well. > >Jon > >>I'm not recommending any one of those over any other, >>and there are other chips from those manufactures and >>others that may suit your needs. >> >>EdA TinyLogic schmitt trigger and a SOT-23 mosfet will make a nice controllable-PWM boost thing. It only needs a 2-terminal inductor, which simplifies life. Sort of like this: ftp://jjlarkin.lmi.net/Z206.pdf John
Reply by ●July 26, 20092009-07-26
On Jul 26, 9:43=A0pm, fungus <openglMYSO...@artlum.com> wrote:> > I don't know where I'd get one around here >As an aside, how do you guys buy parts? Do you have big electronics stores with catalogs or is it through distributors?
Reply by ●July 27, 20092009-07-27
Jon Kirwan wrote:> On Sun, 26 Jul 2009 22:24:34 +1000, David Eather <eather@tpg.com.au> > wrote: > >> fungus wrote: >>> On Jul 26, 8:57 am, ehsjr <eh...@NOSPAMverizon.net> wrote: >>>> I don't _know_ if it qualifies as "a whole lot" better, but >>>> available one chip solutions can meet the op's stated requirement >>>> of keeping the current at 15-20 mA, and the joule thief cannot. >>>> >>> Can you maybe recommend one...? >> LM3909 - but they are hard to get hold of now > > David, is this your recommendation for "one chip solutions can meet > the op's stated requirement of keeping the current at 15-20 mA" for > six 3.3V LEDs? > > It stacks the battery voltage with only one capacitor, to double the > voltage. That's about it. And it doesn't control current over > voltage source variations. > > Here is an LM3909 equivalent that works. R1 and C1 set timing. R8 is > a current limiter, such as it is: > >> : +1.5 +1.5 +1.5 +1.5 +1.5 >> : | | | | | >> : | | | | | >> : | \ | | | >> : | / R7 | Q2 e>| |<e Q1 >> : | \ 410 | 2N5401 |---+---| 2N3906 >> : \ / | c/| | |\c >> : / R8 | | | | | >> : \ 12 | | | | | >> : / | |/c Q4 | | | >> : | +-------+---------| 2N3904 | | | >> : | | | |>e | | | >> : | | | | '-----+ | >> : | | \ | | | >> : | | / R3 | | | >> : | \ \ 22k | | | >> : --- / R6 / | | | >> : \ / D2 \ 410 | | | | >> : --- LED / | | |/c Q3 | >> : | | +------------------------| | >> : | | | | |>e | >> : | | | | 2N3904 | | >> : | C1 | \ | | | >> : | || 150uF | / R4 | | | >> : +------||-------+ \ 10k | | | >> : | || | / | | | >> : | | | | | | >> : | | | | | | >> : | | +-----------' | | >> : | | | \ | >> : | | | / R2 | >> : | | \ \ 100 | >> : | | / R5 / | >> : | | \ 22k | | >> : | | / | | >> : | | | | | >> : | | | | | >> : | | gnd | | >> : +--------------------------------------------------' | >> : | | | >> : | | | >> : | ,--------+ | >> : \ | | | >> : / R1 | | 2N3904 | >> : \ 10k | Q5 c\| | >> : / | |--------------------------------------' >> : | _|_ D1 e<| >> : | /_\ BAT54 | >> : | | | >> : | | | >> : | | | >> : gnd gnd gnd > > Lots of parts and it doesn't meet with Ed's comment. > > JonI like the LM3909, and it would efficiently do the job required (maybe not what ED was thinking) with few additional parts. 1 IC, 1 cap and a couple of resistors.
Reply by ●July 27, 20092009-07-27
Jon Kirwan wrote:> On Sun, 26 Jul 2009 17:06:24 GMT, ehsjr <ehsjr@NOSPAMverizon.net> > wrote: > >> fungus wrote: >>> On Jul 26, 8:57 am, ehsjr <eh...@NOSPAMverizon.net> wrote: >>> >>>> I don't _know_ if it qualifies as "a whole lot" better, but >>>> available one chip solutions can meet the op's stated requirement >>>> of keeping the current at 15-20 mA, and the joule thief cannot. >>> Can you maybe recommend one...? >> Manufacturer chips posted below are just the first few found by a >> Google search with "led boost drivers" in the search box. >> >> National recommends their LM3410X for this. >> http://www.national.com/ds/LM/LM3410.pdf > > $2.50-$3 each. Lots around. > >> TI shows the TPS61160 meeting the requirements. >> http://focus.ti.com/lit/ds/symlink/tps61161a.pdf > > Hmm. Cheaper. $2 each. Lots around. > >> Onsemi has the CAT3606-D >> http://www.onsemi.com/pub_link/Collateral/CAT3606-D.PDF > > Couldn't find the -D around anywhere. But did find CAT3606HV4-T2 at > Digikey for $1 (and at only two other places.) This device cannot > handle more than 4.2V input and must have at least 3V. It's designed > for Li-ion sources and can run in either 1X or 1.5X mode. I'm not > hyped on this as a 'solution.' It's a charge pump with regulation on > the current, I think. > >> Linear's LT3598 will do it: >> http://cds.linear.com/docs/Datasheet/3598fa.pdf > > Mucho expensive. I found them for over $7 each! (Some at under $5, > too.) Only a few places carry them. > > .... > > TI seems to be the one out of the above I'd focus more on. Looks nice > and seems to do the right job for a reasonable price and is at various > stores, as well. > > Jon > >> I'm not recommending any one of those over any other, >> and there are other chips from those manufactures and >> others that may suit your needs. >> >> EdUm, all those chips are in surface mount packages - the OP has bugger all chance of being able to solder them.
Reply by ●July 27, 20092009-07-27
fungus wrote:> Looks like this: http://www.artlum.com/jt/b_to_e.gifI'm confused. Does "b_to_e" mean base-to-emitter? I want to see *collector*-to-emitter. -- Greg
Reply by ●July 27, 20092009-07-27
fungus wrote:> On Jul 26, 7:51 pm, Jon Kirwan <j...@infinitefactors.org> wrote: >>> National recommends their LM3410X for this. >>> http://www.national.com/ds/LM/LM3410.pdf >> $2.50-$3 each. Lots around. >> >>> TI shows the TPS61160 meeting the requirements. >>> http://focus.ti.com/lit/ds/symlink/tps61161a.pdf >> Hmm. Cheaper. $2 each. Lots around. >> > > Maybe there's lots where you live but I don't know where > I'd get one around here, and there's none on eBay. > > But ... while I was trawling eBay I found a lot of people selling > LM3914s. It's a dedicated LED driver chip, can work with 3V > input and drive up to 10 LEDs with programmable current > (up to 30mA each). > > http://www.national.com/mpf/LM/LM3914.html > > > Even better: It has an input sensor making LED bar graphs. > I assume I could just pull the sensor high to turn on all the > LEDs but it opens up lots of fun possibilities - eg. I might be > able to make the LEDs respond to sound, which would be > very cool for processions. > > Almost seems too good to be true ...LM3914 would seem to work a treat - it needs about .9 of a volt more than the LED uses (page 5 "led current regulation drop out") Congratulations on a flexiable view of the problem.
