I'm in the process of building the W1 and have substituted the colored LED's on the SWR readout as has been discussed.
I really haven't been following this thread closely and I haven't finished the W1 build yet so this may have already been covered. I include myself when I say that it seems that everyone seems to be replacing SOME of the red LED's with the green, amber and yellow jobbies. And we seem to be using the red LEDs that came with the W1. Has anyone replaced ALL of the LEDs, including the RED ones. Wouldn't using all now LED's from the same manufacturer, and specs give the desired results of consistent brightness? Again, I didn't do this because I wasn't aware of the issue when started, but the LEDs I got from Mouser were relatively inexpensive (about $0.15 each) so this might have been an easier fix. Perhaps this had previously been covered. Just a thought Tom WB2QDG K2 1103 ----- Original Message ----- From: "Doug Joyce" <d_jo...@sympatico.ca> To: "Bill Johnson" <b...@creeksidecomputing.com>; "'Dave Van Wallaghen'" <w8...@comcast.net>; "'Jack Smith'" <jack.sm...@cliftonlaboratories.com> Cc: <elecraft@mailman.qth.net>; "'Ken Kopp'" <k...@rfwave.net> Sent: Friday, February 20, 2009 10:40 PM Subject: Re: [Elecraft] Leds for W1 > Bill: I've done some further testing and believe it's going to take > increasing the current to approx 6 to 7 ma to get the new coloured LEDs to > be bright enough. That would involve reducing the 2.2 Ks to approx 470 > ohms > and finding a source for a suitable resistor pack. At this higher current > the red LEDs are still brighter than the other colours and there is no > easy > way to separately control the current to individual colours. > > There are also a number of other things to check such as the ability of > the > U3 regulator to handle the increased current. Battery life will also be > reduced and perhaps this "coloured version" needs to be run from a wall > wart. > > 73 > > Doug, VE3MV > > ----- Original Message ----- > From: "Bill Johnson" <b...@creeksidecomputing.com> > To: "'Dave Van Wallaghen'" <w8...@comcast.net>; "'Jack Smith'" > <jack.sm...@cliftonlaboratories.com> > Cc: <elecraft@mailman.qth.net>; "'Ken Kopp'" <k...@rfwave.net> > Sent: Friday, February 20, 2009 6:59 PM > Subject: Re: [Elecraft] Leds for W1 > > >> Thanks for the excellent discussion and possible solutions. Please > include >> me in the effort to experiment. My Hakko 808 hasn't been used for a >> month >> so I wouldn't mind helping out. I will gladly put in some $'s to >> purchase >> parts/share in cost to get at a solution. Suggestion: if the green and >> yellow output is sufficient and the amber is the only low output, perhaps > it >> might best to revert back to either yellow or red... the user could > decide. >> >> Let me know what I can do. I would also be ok with replacing the drive >> resistors to boost the LED output for SWR readings: perhaps reducing the >> Power LED output slightly might be a power consideration for battery >> conservation. >> >> >> 73, >> >> Bill >> K9YEQ >> K2 #35; KX1 #35; K3 #1744; mini mods >> >> >> -----Original Message----- >> ............... my guess is that the W1 was designed for low >> current consumption being battery operated and used for portable ops. So >> I'm sure your calculations are right on. >> >> ............... >> ordered the Lumex line of red, yellow and green leds that Doug spoke >> about. They are all very close in forward voltage and are all rated at >> 10mcd output. I also ordered the amber, although it is only rated at >> 5mcd and their super red which is rated at 80mcd. I will try these out >> on my W1 to see the differences. Besides, I just bought a new Hakko 808 >> I've been wanting to try out. >> >> My guess is at worst, the power scale leds may be brighter than the SWR >> scale, but I can at least get the SWR uniform in brightness. Other than >> that, it might take replacing the power scale leds as well for those who >> want it totally uniform. Or like Jack alluded to, replacing the series >> resistors which doesn't sound like much fun to me (and possibly >> increasing current consumption). >> >> I will make current measurements before I replace anything and record >> the changes in current while experimenting. I will post my results back >> to the list. If there is enough interest (and it seems like there is) I >> would not mind ordering these in quantity and a splitting them up .... >> 73, >> Dave W8FGU >> >> Jack Smith wrote: >> > I have some experience driving LEDs from a PIC (both in my book >> > Programming the PIC Microcontroller with MBasic) as well as the Z100 CW >> > tuning aid kit that I developed. (Still available, should anyone be >> > interested, as well as the book is still in print.) >> > >> > The Z100 uses red, yellow and green rectangular LEDs, driven from a >> > PIC >> > with a small series resistor. >> > http://www.cliftonlaboratories.com/z100_tuning_aid.htm for more >> > details. >> > >> > For all practical purposes, a PIC won't source more than about 20 mA >> > even into a short circuit. Looking at the W1's schematic (I don't own >> > one) it seems that the maximum current available to drive an LED is >> > around 1.5 mA (5V from the PIC, less 2V drop for the LED average, with >> > 2K ohm series from the PIC output. The 2N7000's on resistance can be >> > ignored in this calculation.) That's quite low current, and it should >> > be >> > possible to boost it--and the LED's brightness--considerably by >> > reducing >> > the 2K series resistors. >> > >> > My experience is that although perhaps not designed that way, PICs are >> > pretty abuse tolerant in the output mode. My Z100 drives the LEDs >> > through 43 ohm resistors and the LEDs are quite bright. The Z100's >> > typical LED driving current is around 10 mA if I remember the >> > measurements correctly. >> > >> > A couple of caveats - the Z100 does not run with all the LEDs >> > illuminated under normal conditions. With noise, perhaps three or four >> > are at at maximum, and with a signal input, one or two. Hence the >> > Z100's+5V regulator is not designed to provide oodles of current. >> > Second, there is a dissipation limit on how much total current a PIC >> > can >> > source from all pins. If the W1 operates in a mode where most LEDs are >> > on for extended periods, I would evaluate the 5V regulator's thermal >> > performance and also the PIC's maximum power dissipation before getting >> > carried away with reducing the series driver resistors. >> > >> > As usual, should anyone destroy their W1 through making these changes, >> > you are on your own. >> > >> > Jack K8ZOA >> > www.cliftonlaboratories.com >> > >> > >> > >> > Doug Joyce wrote: >> >> Dave / Ken: >> >> >> >> Further to the attached: >> >> >> >> Gary provided the info on the Red LED as "the Digi-key part# is >> >> 516-1281-ND & the Mfg is Avago Tech part # HLMP-S100." >> >> This part is listed in the Digi-Key T091 (Jan - Apr 2009) catalogue, >> >> page 2615. The same section also lists two green LEDs, the brighter >> >> is Digi-Key part # 516-1285-ND (Avago part # HLMP-S501). >> >> Interestingly enough the T081 catalogue (page 2455) also listed a >> >> "yellow" from the same series as Digi-Key part # 516-1284-ND (Avago >> >> part # HLMP-S301), but when I tried to get a quote, the minimum order >> >> qty was over 5000 units. Orange is also made by Avago as part # >> >> HLMP-S401 (same Digi-Key part No.) with a minimum order qty of 3,000 >> >> units. So green seems to be the only other LED from the same Avago >> >> family available in reasonable quantities. (The Mouser part numbers >> >> for the Avago Tech LEDs are 630-HLMP-Sxxx etc) >> >> >> >> For the "red" LED Luminous intensity is given as 7.5 mcd @ 20 ma with >> >> a fwd voltage drop of 1.8 volts; however for the "green" (S501) the >> >> specs are 8 mcd @ 20 ma with a fwd voltage drop of 2.2 volts. I >> >> suspect that this 0.4 volt difference may be the cause of the >> >> difference in intensity when installed in the W1. >> >> As for yellow and orange / amber LEDs from an alternate supplier, the >> >> same T091 catalogue, page 2557 shows LEDs from Lumex. >> >> "Yellow" is Digi-Key part # 67-1050-ND (Lumex part # SSL-LX2573-YD). >> >> Fwd voltage drop of 2.1V & luminosity of 10 mcd; and >> >> "Amber" is Digi-Key part # 67-1045-ND (Lumex part # SSL-LX-2573-AD). >> >> Fwd voltage drop of 2.0 & luminosity of 5 mcd >> >> (The Mouser part numbers for the Lumex LEDs are 696-SSL-LX2573xxx > etc). >> >> >> >> I ordered a qty of >> >> 526-1285-ND (HLMP-S501) , green from Avago and >> >> 67-1050-ND (SSL-LX2573-YD), yellow from Lumex and >> >> 67-1045-ND (SSL-LX2573-AD), amber from Lumex >> >> >> >> Connected to a 12V supply with a resistor to limit the current to 20 >> >> ma, the intensity seems to be similar in all LEDs (including the >> >> original red one). When installed in the W1 however, it's a >> >> different story. (See my comment in the email below.) All of the >> >> other colours are significantly less bright than the original "red" > ones. >> >> >> >> Perhaps someone who has worked with the PIC microcontroller might be >> >> able to suggest a solution. >> >> >> >> 73 >> >> >> >> Doug, VE3MV >> >> ----- Original Message ----- >> >> *From:* Doug Joyce <mailto:d_jo...@sympatico.ca> >> >> *To:* Dave Van Wallaghen <mailto:w8...@comcast.net> >> >> *Sent:* Friday, February 20, 2009 9:11 AM >> >> *Subject:* Leds for W1 >> >> >> >> Dave: I'm not sure the email I cc'd you on earlier got sent, so >> >> here is a resend. >> >> Ken / Dave: Just to let you know, I did this with equivalent > / >> >> the same parts (I'll provide the part numbers I used later this >> >> AM) and at 20 ma fwd current they do indeed seem to all have >> >> equivalent brightness. The problem I found is that when installed >> >> in the W1, they don't light up with the same intensity as the red >> >> ones supplied. I used other colours of green, yellow and amber / >> >> orange. >> >> I haven't spent a lot of time to investigate, but what I >> >> found so >> >> far is that the fwd voltage drop on the red LEDs is smaller than >> >> on the other colours, and in the W1 cct it is a smaller percentage >> >> of the supply voltage of 5 volts. This results in more fwd >> >> current that available for the red compared to the other colours, >> >> hence the red appears to be brighter. The next step I need to do >> >> is to actually measure the current provided by the W1 for these >> >> other colours. >> >> I got 10 of each when I ordered then from DigiKey - Dave, if >> >> you >> >> provide your mailing address, I'll send you a couple of each and >> >> you can try then in the W1 as well. >> >> 73 >> >> Doug, VE3MV >> >> >> >> ----- Original Message ----- >> >> *From:* Ken Kopp <mailto:k...@rfwave.net> >> >> *To:* w8...@comcast.net <mailto:w8...@comcast.net> ; Doug >> >> Joyce <mailto:d_jo...@sympatico.ca> ; elecraft@mailman.qth.net >> >> <mailto:elecraft@mailman.qth.net> >> >> *Sent:* Thursday, February 19, 2009 10:52 PM >> >> *Subject:* Re: [Elecraft] W1 LED Part Numbers >> >> >> >> I have a "set" of additional green and yellow LED's >> >> from Scott at Aptos. He got them for me from the >> >> stock bins and didn't include their stock numbers. >> >> I'll light them with a PS and see if their all the > same >> >> brightness and take a photo. >> >> They -should- be the same product line and therefore >> >> light equally, I'd think. They're from the KAT-100 >> >> tuner. >> >> Scott was at least receptive to making all the W1 >> >> kits with three colors of LED's. >> >> 73! Ken >> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:Elecraft@mailman.qth.net >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> >> > > > -- > I am using the free version of SPAMfighter. > We are a community of 6 million users fighting spam. > SPAMfighter has removed 1012 of my spam emails to date. > Get the free SPAMfighter here: http://www.spamfighter.com/len > > The Professional version does not have this message > > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
