On Sun, 14 May 2017 01:07:57 -0400, Bob Engelhardt <BobEngelhardt@comcast.net> wrote:>On 5/13/2017 6:00 PM, Bob Engelhardt wrote: >> On 5/13/2017 1:47 PM, default wrote: >>> On Sat, 13 May 2017 08:35:23 -0700, John Larkin >>>> 50.625 watt hours???!!! >>> >>> It's magic, or a decimal point slipped 2 places. 1/2 watt I might >>> believe. >>> >>> Damn good caps for what I'm doing with them though... >>> >> >> 50F x 2.7v = 135C = 135As = 135/3600Ah = 0.0374Ah >> >> 50.625Wh /.0375Ah = 1350v >> >> Point slipped 3 places, I think. .05625Wh > >Oops ... .50625 ... there's your 1/2Wh "default"I think you had it right at .05 Watt Hours
Is this scheme reasonable?
Started by ●May 10, 2017
Reply by ●May 14, 20172017-05-14
Reply by ●May 18, 20172017-05-18
On 2017-05-13, default <default@defaulter.net> wrote:> On Sat, 13 May 2017 08:35:23 -0700, John Larkin ><jjlarkin@highlandtechnology.com> wrote: > >>On Fri, 12 May 2017 06:47:01 -0400, default <default@defaulter.net> >>wrote: >> >>>On Fri, 12 May 2017 10:47:54 +0200, o pere o <me@somewhere.net> wrote: >>> >>>>On 11/05/17 00:42, Phil Hobbs wrote: >>>>> On 05/10/2017 02:31 PM, John Larkin wrote: >>>>>> On Wed, 10 May 2017 09:57:21 -0700, etpm@whidbey.com wrote: >>>>>> >>>>>>> I have an automatic opening trash can in the kitchen that runs off of >>>>>>> batteries. I wanna run it with a wall wart. When the lid opens it >>>>>>> draws more power than the 750 mA wall wart I tried using to power it >>>>>>> could deliver. This makes sense. I don't want to use a bigger wall >>>>>>> wart and I don't want to have betteries in it all the time to provide >>>>>>> the current. I'm thinking instead of using a capacitor. If the current >>>>>>> and voltage draw as well as the duration to open the lid is measured >>>>>>> can that not be used to calculate the minimum size capacitor? And if >>>>>>> not excessive maybe a cap that would open the lid three or four times >>>>>>> in a row could be used in place of the 6 AA cells it uses now. >>>>>>> Reasonable? >>>>>>> Thanks, >>>>>>> Eric >>>>>> >>>>>> A conventional cap, no. Maybe a super expensive supercap. >>>>>> >>>>>> I wouldn't want an electronic trash can. All that cheap, badly >>>>>> programmed microprocessor/LCD appliance junk will break in a couple of >>>>>> years, and be annoying meanwhile. >>>>>> >>>>>> *SIX* AA cells? How long do they last? >>>>>> >>>>>> >>>>> >>>>> A couple of supercaps in series might work fine. For instance, >>>>> SCMT22C505MRBA0 AVX CAPACITOR 5F 20% 5V 0.065ohms $5.23000 in onesies >>>>> from Digikey. >>>>> >>>>> Two of those in series, with a TL431 across each one (set for 4.8V or >>>>> so) to equalize the voltage, plus a charger with about a 50 mA current >>>>> limit ought to work, I should think. >>>>> >>>>> Cheers >>>>> >>>>> Phil Hobbs >>>>> >>>> >>>>Is there data on leakage or self-discharge of these beasts? The >>>>datasheet just says "low leakage current" and this could just mean >>>>anything... >>>> >>>>Pere >>> >>>The caps I'm using give the leakage at .16 ma. >>> >>>http://www.illinoiscapacitor.com/ic_search/super_products_detail.aspx?icpartnumber=700020 >> >> >>50.625 watt hours???!!! > > It's magic, or a decimal point slipped 2 places. 1/2 watt I might > believe.more like 3 decimal places, 0.5*C*V*V/3600 -- This email has not been checked by half-arsed antivirus software
Reply by ●May 18, 20172017-05-18
On 18 May 2017 06:00:58 GMT, Jasen Betts <jasen@xnet.co.nz> wrote:>On 2017-05-13, default <default@defaulter.net> wrote: >> On Sat, 13 May 2017 08:35:23 -0700, John Larkin >><jjlarkin@highlandtechnology.com> wrote: >> >>>On Fri, 12 May 2017 06:47:01 -0400, default <default@defaulter.net> >>>wrote: >>> >>>>On Fri, 12 May 2017 10:47:54 +0200, o pere o <me@somewhere.net> wrote: >>>> >>>>>On 11/05/17 00:42, Phil Hobbs wrote: >>>>>> On 05/10/2017 02:31 PM, John Larkin wrote: >>>>>>> On Wed, 10 May 2017 09:57:21 -0700, etpm@whidbey.com wrote: >>>>>>> >>>>>>>> I have an automatic opening trash can in the kitchen that runs off of >>>>>>>> batteries. I wanna run it with a wall wart. When the lid opens it >>>>>>>> draws more power than the 750 mA wall wart I tried using to power it >>>>>>>> could deliver. This makes sense. I don't want to use a bigger wall >>>>>>>> wart and I don't want to have betteries in it all the time to provide >>>>>>>> the current. I'm thinking instead of using a capacitor. If the current >>>>>>>> and voltage draw as well as the duration to open the lid is measured >>>>>>>> can that not be used to calculate the minimum size capacitor? And if >>>>>>>> not excessive maybe a cap that would open the lid three or four times >>>>>>>> in a row could be used in place of the 6 AA cells it uses now. >>>>>>>> Reasonable? >>>>>>>> Thanks, >>>>>>>> Eric >>>>>>> >>>>>>> A conventional cap, no. Maybe a super expensive supercap. >>>>>>> >>>>>>> I wouldn't want an electronic trash can. All that cheap, badly >>>>>>> programmed microprocessor/LCD appliance junk will break in a couple of >>>>>>> years, and be annoying meanwhile. >>>>>>> >>>>>>> *SIX* AA cells? How long do they last? >>>>>>> >>>>>>> >>>>>> >>>>>> A couple of supercaps in series might work fine. For instance, >>>>>> SCMT22C505MRBA0 AVX CAPACITOR 5F 20% 5V 0.065ohms $5.23000 in onesies >>>>>> from Digikey. >>>>>> >>>>>> Two of those in series, with a TL431 across each one (set for 4.8V or >>>>>> so) to equalize the voltage, plus a charger with about a 50 mA current >>>>>> limit ought to work, I should think. >>>>>> >>>>>> Cheers >>>>>> >>>>>> Phil Hobbs >>>>>> >>>>> >>>>>Is there data on leakage or self-discharge of these beasts? The >>>>>datasheet just says "low leakage current" and this could just mean >>>>>anything... >>>>> >>>>>Pere >>>> >>>>The caps I'm using give the leakage at .16 ma. >>>> >>>>http://www.illinoiscapacitor.com/ic_search/super_products_detail.aspx?icpartnumber=700020 >>> >>> >>>50.625 watt hours???!!! >> >> It's magic, or a decimal point slipped 2 places. 1/2 watt I might >> believe. > >more like 3 decimal places, 0.5*C*V*V/3600I agree. Did the math and posted as much on 5/14. I'm thinking they mistakenly used some "one size fits all" or watt-hours per X farads. In a related experiment... I'm temporarily using some Maxwell "D-cell" series caps to power the buoy flasher that got 6 months of use from 3-AA alkaline cells, switching to a solar charged, 175 F, 3 V system (using caps that cost $15 each). That system is flashing the strobe, for 8 days on the charge it can get in one day. (cover the solar cells with aluminum foil and wait till it dies). So a pair of the $1.29 50 F caps should easily last a day, or perhaps just use one 50 F and go with 2.5V. (specs on the controller that I'm using says it works down to 2.2V, and it seems to recover and start running it's program from the beginning when the voltage gets to about 2V) The buoy that I'm illuminating belongs to the city.. So I have to keep the cost low in case they discover that I've modified the buoy and decide to remove my strobe, or vandals (or Visigoths) make it to that end of the lake and steal or destroy it... It's become a "thing" to tweak the buoy with something different each year. I go kayaking at 3:30 AM to avoid the summer heat, but it's a challenge to find ways to see where I'm going in the dark on a lake that's 2 miles long. Radio beacon? or perhaps a super strobe that I can trigger from 2 miles away?
Reply by ●May 18, 20172017-05-18
On Thu, 18 May 2017 07:41:04 -0400, default <default@defaulter.net> wrote:>On 18 May 2017 06:00:58 GMT, Jasen Betts <jasen@xnet.co.nz> wrote: > >>On 2017-05-13, default <default@defaulter.net> wrote: >>> On Sat, 13 May 2017 08:35:23 -0700, John Larkin >>><jjlarkin@highlandtechnology.com> wrote: >>> >>>>On Fri, 12 May 2017 06:47:01 -0400, default <default@defaulter.net> >>>>wrote: >>>> >>>>>On Fri, 12 May 2017 10:47:54 +0200, o pere o <me@somewhere.net> wrote: >>>>> >>>>>>On 11/05/17 00:42, Phil Hobbs wrote: >>>>>>> On 05/10/2017 02:31 PM, John Larkin wrote: >>>>>>>> On Wed, 10 May 2017 09:57:21 -0700, etpm@whidbey.com wrote: >>>>>>>> >>>>>>>>> I have an automatic opening trash can in the kitchen that runs off of >>>>>>>>> batteries. I wanna run it with a wall wart. When the lid opens it >>>>>>>>> draws more power than the 750 mA wall wart I tried using to power it >>>>>>>>> could deliver. This makes sense. I don't want to use a bigger wall >>>>>>>>> wart and I don't want to have betteries in it all the time to provide >>>>>>>>> the current. I'm thinking instead of using a capacitor. If the current >>>>>>>>> and voltage draw as well as the duration to open the lid is measured >>>>>>>>> can that not be used to calculate the minimum size capacitor? And if >>>>>>>>> not excessive maybe a cap that would open the lid three or four times >>>>>>>>> in a row could be used in place of the 6 AA cells it uses now. >>>>>>>>> Reasonable? >>>>>>>>> Thanks, >>>>>>>>> Eric >>>>>>>> >>>>>>>> A conventional cap, no. Maybe a super expensive supercap. >>>>>>>> >>>>>>>> I wouldn't want an electronic trash can. All that cheap, badly >>>>>>>> programmed microprocessor/LCD appliance junk will break in a couple of >>>>>>>> years, and be annoying meanwhile. >>>>>>>> >>>>>>>> *SIX* AA cells? How long do they last? >>>>>>>> >>>>>>>> >>>>>>> >>>>>>> A couple of supercaps in series might work fine. For instance, >>>>>>> SCMT22C505MRBA0 AVX CAPACITOR 5F 20% 5V 0.065ohms $5.23000 in onesies >>>>>>> from Digikey. >>>>>>> >>>>>>> Two of those in series, with a TL431 across each one (set for 4.8V or >>>>>>> so) to equalize the voltage, plus a charger with about a 50 mA current >>>>>>> limit ought to work, I should think. >>>>>>> >>>>>>> Cheers >>>>>>> >>>>>>> Phil Hobbs >>>>>>> >>>>>> >>>>>>Is there data on leakage or self-discharge of these beasts? The >>>>>>datasheet just says "low leakage current" and this could just mean >>>>>>anything... >>>>>> >>>>>>Pere >>>>> >>>>>The caps I'm using give the leakage at .16 ma. >>>>> >>>>>http://www.illinoiscapacitor.com/ic_search/super_products_detail.aspx?icpartnumber=700020 >>>> >>>> >>>>50.625 watt hours???!!! >>> >>> It's magic, or a decimal point slipped 2 places. 1/2 watt I might >>> believe. >> >>more like 3 decimal places, 0.5*C*V*V/3600 > >I agree. Did the math and posted as much on 5/14. > >I'm thinking they mistakenly used some "one size fits all" or >watt-hours per X farads. > >In a related experiment... I'm temporarily using some Maxwell "D-cell" >series caps to power the buoy flasher that got 6 months of use from >3-AA alkaline cells, switching to a solar charged, 175 F, 3 V system >(using caps that cost $15 each). That system is flashing the strobe, >for 8 days on the charge it can get in one day. (cover the solar >cells with aluminum foil and wait till it dies). > >So a pair of the $1.29 50 F caps should easily last a day, or perhaps >just use one 50 F and go with 2.5V. (specs on the controller that I'm >using says it works down to 2.2V, and it seems to recover and start >running it's program from the beginning when the voltage gets to about >2V) > >The buoy that I'm illuminating belongs to the city.. So I have to keep >the cost low in case they discover that I've modified the buoy and >decide to remove my strobe, or vandals (or Visigoths) make it to that >end of the lake and steal or destroy it... > >It's become a "thing" to tweak the buoy with something different each >year. I go kayaking at 3:30 AM to avoid the summer heat, but it's a >challenge to find ways to see where I'm going in the dark on a lake >that's 2 miles long. > >Radio beacon? or perhaps a super strobe that I can trigger from 2 >miles away?Tritium light? Strontium aluminate paint? Both would be fairly short range visibility. For longer range, why not use GPS? -- John Larkin Highland Technology, Inc lunatic fringe electronics
Reply by ●May 19, 20172017-05-19
On Thu, 18 May 2017 08:43:17 -0700, John Larkin <jjlarkin@highlandtechnology.com> wrote:>On Thu, 18 May 2017 07:41:04 -0400, default <default@defaulter.net> >wrote: > >>On 18 May 2017 06:00:58 GMT, Jasen Betts <jasen@xnet.co.nz> wrote: >> >>>On 2017-05-13, default <default@defaulter.net> wrote: >>>> On Sat, 13 May 2017 08:35:23 -0700, John Larkin >>>><jjlarkin@highlandtechnology.com> wrote: >>>> >>>>>On Fri, 12 May 2017 06:47:01 -0400, default <default@defaulter.net> >>>>>wrote: >>>>> >>>>>>On Fri, 12 May 2017 10:47:54 +0200, o pere o <me@somewhere.net> wrote: >>>>>> >>>>>>>On 11/05/17 00:42, Phil Hobbs wrote: >>>>>>>> On 05/10/2017 02:31 PM, John Larkin wrote: >>>>>>>>> On Wed, 10 May 2017 09:57:21 -0700, etpm@whidbey.com wrote: >>>>>>>>> >>>>>>>>>> I have an automatic opening trash can in the kitchen that runs off of >>>>>>>>>> batteries. I wanna run it with a wall wart. When the lid opens it >>>>>>>>>> draws more power than the 750 mA wall wart I tried using to power it >>>>>>>>>> could deliver. This makes sense. I don't want to use a bigger wall >>>>>>>>>> wart and I don't want to have betteries in it all the time to provide >>>>>>>>>> the current. I'm thinking instead of using a capacitor. If the current >>>>>>>>>> and voltage draw as well as the duration to open the lid is measured >>>>>>>>>> can that not be used to calculate the minimum size capacitor? And if >>>>>>>>>> not excessive maybe a cap that would open the lid three or four times >>>>>>>>>> in a row could be used in place of the 6 AA cells it uses now. >>>>>>>>>> Reasonable? >>>>>>>>>> Thanks, >>>>>>>>>> Eric >>>>>>>>> >>>>>>>>> A conventional cap, no. Maybe a super expensive supercap. >>>>>>>>> >>>>>>>>> I wouldn't want an electronic trash can. All that cheap, badly >>>>>>>>> programmed microprocessor/LCD appliance junk will break in a couple of >>>>>>>>> years, and be annoying meanwhile. >>>>>>>>> >>>>>>>>> *SIX* AA cells? How long do they last? >>>>>>>>> >>>>>>>>> >>>>>>>> >>>>>>>> A couple of supercaps in series might work fine. For instance, >>>>>>>> SCMT22C505MRBA0 AVX CAPACITOR 5F 20% 5V 0.065ohms $5.23000 in onesies >>>>>>>> from Digikey. >>>>>>>> >>>>>>>> Two of those in series, with a TL431 across each one (set for 4.8V or >>>>>>>> so) to equalize the voltage, plus a charger with about a 50 mA current >>>>>>>> limit ought to work, I should think. >>>>>>>> >>>>>>>> Cheers >>>>>>>> >>>>>>>> Phil Hobbs >>>>>>>> >>>>>>> >>>>>>>Is there data on leakage or self-discharge of these beasts? The >>>>>>>datasheet just says "low leakage current" and this could just mean >>>>>>>anything... >>>>>>> >>>>>>>Pere >>>>>> >>>>>>The caps I'm using give the leakage at .16 ma. >>>>>> >>>>>>http://www.illinoiscapacitor.com/ic_search/super_products_detail.aspx?icpartnumber=700020 >>>>> >>>>> >>>>>50.625 watt hours???!!! >>>> >>>> It's magic, or a decimal point slipped 2 places. 1/2 watt I might >>>> believe. >>> >>>more like 3 decimal places, 0.5*C*V*V/3600 >> >>I agree. Did the math and posted as much on 5/14. >> >>I'm thinking they mistakenly used some "one size fits all" or >>watt-hours per X farads. >> >>In a related experiment... I'm temporarily using some Maxwell "D-cell" >>series caps to power the buoy flasher that got 6 months of use from >>3-AA alkaline cells, switching to a solar charged, 175 F, 3 V system >>(using caps that cost $15 each). That system is flashing the strobe, >>for 8 days on the charge it can get in one day. (cover the solar >>cells with aluminum foil and wait till it dies). >> >>So a pair of the $1.29 50 F caps should easily last a day, or perhaps >>just use one 50 F and go with 2.5V. (specs on the controller that I'm >>using says it works down to 2.2V, and it seems to recover and start >>running it's program from the beginning when the voltage gets to about >>2V) >> >>The buoy that I'm illuminating belongs to the city.. So I have to keep >>the cost low in case they discover that I've modified the buoy and >>decide to remove my strobe, or vandals (or Visigoths) make it to that >>end of the lake and steal or destroy it... >> >>It's become a "thing" to tweak the buoy with something different each >>year. I go kayaking at 3:30 AM to avoid the summer heat, but it's a >>challenge to find ways to see where I'm going in the dark on a lake >>that's 2 miles long. >> >>Radio beacon? or perhaps a super strobe that I can trigger from 2 >>miles away? > >Tritium light? > >Strontium aluminate paint? > >Both would be fairly short range visibility. For longer range, why not >use GPS?Tried that too. Got a Magellan "waterproof" little hand-held thingee. Cost a small fortune and wasn't waterproof enough to take dunking in water. Since they stopped the extended warranty plan, I stopped taking it kayaking. It was hard to read too... The nice thing about it was when I was on a new creek, I could see my progress.
Reply by ●May 19, 20172017-05-19
On Wednesday, May 10, 2017 at 9:50:41 AM UTC-7, et...@whidbey.com wrote:> I have an automatic opening trash can in the kitchen that runs off of > batteries. I wanna run it with a wall wart. When the lid opens it > draws more power than the 750 mA wall wart I tried using to power it > could deliver. This makes sense. I don't want to use a bigger wall > wart and I don't want to have betteries in it all the time to provide > the current. I'm thinking instead of using a capacitor. If the current > and voltage draw as well as the duration to open the lid is measured > can that not be used to calculate the minimum size capacitor? And if > not excessive maybe a cap that would open the lid three or four times > in a row could be used in place of the 6 AA cells it uses now. > Reasonable? > Thanks, > EricNah, go for a 2-stroke gasoline-powered trash can :D I wonder if this could work. https://www.walmart.com/ip/Scosche-500K-Micro-Farad-Capacitor/46997835 Michael
Reply by ●May 19, 20172017-05-19
On 5/19/2017 6:55 AM, default wrote:> On Thu, 18 May 2017 08:43:17 -0700, John Larkin > <jjlarkin@highlandtechnology.com> wrote: > >> On Thu, 18 May 2017 07:41:04 -0400, default <default@defaulter.net> >> wrote: >> >>> On 18 May 2017 06:00:58 GMT, Jasen Betts <jasen@xnet.co.nz> wrote: >>> >>>> On 2017-05-13, default <default@defaulter.net> wrote: >>>>> On Sat, 13 May 2017 08:35:23 -0700, John Larkin >>>>> <jjlarkin@highlandtechnology.com> wrote: >>>>> >>>>>> On Fri, 12 May 2017 06:47:01 -0400, default <default@defaulter.net> >>>>>> wrote: >>>>>> >>>>>>> On Fri, 12 May 2017 10:47:54 +0200, o pere o <me@somewhere.net> wrote: >>>>>>> >>>>>>>> On 11/05/17 00:42, Phil Hobbs wrote: >>>>>>>>> On 05/10/2017 02:31 PM, John Larkin wrote: >>>>>>>>>> On Wed, 10 May 2017 09:57:21 -0700, etpm@whidbey.com wrote: >>>>>>>>>> >>>>>>>>>>> I have an automatic opening trash can in the kitchen that runs off of >>>>>>>>>>> batteries. I wanna run it with a wall wart. When the lid opens it >>>>>>>>>>> draws more power than the 750 mA wall wart I tried using to power it >>>>>>>>>>> could deliver. This makes sense. I don't want to use a bigger wall >>>>>>>>>>> wart and I don't want to have betteries in it all the time to provide >>>>>>>>>>> the current. I'm thinking instead of using a capacitor. If the current >>>>>>>>>>> and voltage draw as well as the duration to open the lid is measured >>>>>>>>>>> can that not be used to calculate the minimum size capacitor? And if >>>>>>>>>>> not excessive maybe a cap that would open the lid three or four times >>>>>>>>>>> in a row could be used in place of the 6 AA cells it uses now. >>>>>>>>>>> Reasonable? >>>>>>>>>>> Thanks, >>>>>>>>>>> Eric >>>>>>>>>> >>>>>>>>>> A conventional cap, no. Maybe a super expensive supercap. >>>>>>>>>> >>>>>>>>>> I wouldn't want an electronic trash can. All that cheap, badly >>>>>>>>>> programmed microprocessor/LCD appliance junk will break in a couple of >>>>>>>>>> years, and be annoying meanwhile. >>>>>>>>>> >>>>>>>>>> *SIX* AA cells? How long do they last? >>>>>>>>>> >>>>>>>>>> >>>>>>>>> >>>>>>>>> A couple of supercaps in series might work fine. For instance, >>>>>>>>> SCMT22C505MRBA0 AVX CAPACITOR 5F 20% 5V 0.065ohms $5.23000 in onesies >>>>>>>>> from Digikey. >>>>>>>>> >>>>>>>>> Two of those in series, with a TL431 across each one (set for 4.8V or >>>>>>>>> so) to equalize the voltage, plus a charger with about a 50 mA current >>>>>>>>> limit ought to work, I should think. >>>>>>>>> >>>>>>>>> Cheers >>>>>>>>> >>>>>>>>> Phil Hobbs >>>>>>>>> >>>>>>>> >>>>>>>> Is there data on leakage or self-discharge of these beasts? The >>>>>>>> datasheet just says "low leakage current" and this could just mean >>>>>>>> anything... >>>>>>>> >>>>>>>> Pere >>>>>>> >>>>>>> The caps I'm using give the leakage at .16 ma. >>>>>>> >>>>>>> http://www.illinoiscapacitor.com/ic_search/super_products_detail.aspx?icpartnumber=700020 >>>>>> >>>>>> >>>>>> 50.625 watt hours???!!! >>>>> >>>>> It's magic, or a decimal point slipped 2 places. 1/2 watt I might >>>>> believe. >>>> >>>> more like 3 decimal places, 0.5*C*V*V/3600 >>> >>> I agree. Did the math and posted as much on 5/14. >>> >>> I'm thinking they mistakenly used some "one size fits all" or >>> watt-hours per X farads. >>> >>> In a related experiment... I'm temporarily using some Maxwell "D-cell" >>> series caps to power the buoy flasher that got 6 months of use from >>> 3-AA alkaline cells, switching to a solar charged, 175 F, 3 V system >>> (using caps that cost $15 each). That system is flashing the strobe, >>> for 8 days on the charge it can get in one day. (cover the solar >>> cells with aluminum foil and wait till it dies). >>> >>> So a pair of the $1.29 50 F caps should easily last a day, or perhaps >>> just use one 50 F and go with 2.5V. (specs on the controller that I'm >>> using says it works down to 2.2V, and it seems to recover and start >>> running it's program from the beginning when the voltage gets to about >>> 2V) >>> >>> The buoy that I'm illuminating belongs to the city.. So I have to keep >>> the cost low in case they discover that I've modified the buoy and >>> decide to remove my strobe, or vandals (or Visigoths) make it to that >>> end of the lake and steal or destroy it... >>> >>> It's become a "thing" to tweak the buoy with something different each >>> year. I go kayaking at 3:30 AM to avoid the summer heat, but it's a >>> challenge to find ways to see where I'm going in the dark on a lake >>> that's 2 miles long. >>> >>> Radio beacon? or perhaps a super strobe that I can trigger from 2 >>> miles away? >> >> Tritium light? >> >> Strontium aluminate paint? >> >> Both would be fairly short range visibility. For longer range, why not >> use GPS? > > Tried that too. Got a Magellan "waterproof" little hand-held thingee. > Cost a small fortune and wasn't waterproof enough to take dunking in > water. Since they stopped the extended warranty plan, I stopped > taking it kayaking. It was hard to read too... > > The nice thing about it was when I was on a new creek, I could see my > progress.They are rated as waterproof, but not very waterproof. I've yet to find one that will survive on the deck of a kayak for more than a season. Sooner or later they leak and crap out. I've never had any trouble seeing where I'm going. Even starlight is enough to navigate. Once the stars are gone you have to know your terrain (aquaine?) pretty well though. Overcast makes for interesting trips though. I take you paddle where there is no illumination from houses and such? Even a single porch light in the distance can provide orientation. -- Rick C
Reply by ●May 19, 20172017-05-19
On Fri, 19 May 2017 06:55:25 -0400, default <default@defaulter.net> wrote:>On Thu, 18 May 2017 08:43:17 -0700, John Larkin ><jjlarkin@highlandtechnology.com> wrote: > >>On Thu, 18 May 2017 07:41:04 -0400, default <default@defaulter.net> >>wrote: >> >>>On 18 May 2017 06:00:58 GMT, Jasen Betts <jasen@xnet.co.nz> wrote: >>> >>>>On 2017-05-13, default <default@defaulter.net> wrote: >>>>> On Sat, 13 May 2017 08:35:23 -0700, John Larkin >>>>><jjlarkin@highlandtechnology.com> wrote: >>>>> >>>>>>On Fri, 12 May 2017 06:47:01 -0400, default <default@defaulter.net> >>>>>>wrote: >>>>>> >>>>>>>On Fri, 12 May 2017 10:47:54 +0200, o pere o <me@somewhere.net> wrote: >>>>>>> >>>>>>>>On 11/05/17 00:42, Phil Hobbs wrote: >>>>>>>>> On 05/10/2017 02:31 PM, John Larkin wrote: >>>>>>>>>> On Wed, 10 May 2017 09:57:21 -0700, etpm@whidbey.com wrote: >>>>>>>>>> >>>>>>>>>>> I have an automatic opening trash can in the kitchen that runs off of >>>>>>>>>>> batteries. I wanna run it with a wall wart. When the lid opens it >>>>>>>>>>> draws more power than the 750 mA wall wart I tried using to power it >>>>>>>>>>> could deliver. This makes sense. I don't want to use a bigger wall >>>>>>>>>>> wart and I don't want to have betteries in it all the time to provide >>>>>>>>>>> the current. I'm thinking instead of using a capacitor. If the current >>>>>>>>>>> and voltage draw as well as the duration to open the lid is measured >>>>>>>>>>> can that not be used to calculate the minimum size capacitor? And if >>>>>>>>>>> not excessive maybe a cap that would open the lid three or four times >>>>>>>>>>> in a row could be used in place of the 6 AA cells it uses now. >>>>>>>>>>> Reasonable? >>>>>>>>>>> Thanks, >>>>>>>>>>> Eric >>>>>>>>>> >>>>>>>>>> A conventional cap, no. Maybe a super expensive supercap. >>>>>>>>>> >>>>>>>>>> I wouldn't want an electronic trash can. All that cheap, badly >>>>>>>>>> programmed microprocessor/LCD appliance junk will break in a couple of >>>>>>>>>> years, and be annoying meanwhile. >>>>>>>>>> >>>>>>>>>> *SIX* AA cells? How long do they last? >>>>>>>>>> >>>>>>>>>> >>>>>>>>> >>>>>>>>> A couple of supercaps in series might work fine. For instance, >>>>>>>>> SCMT22C505MRBA0 AVX CAPACITOR 5F 20% 5V 0.065ohms $5.23000 in onesies >>>>>>>>> from Digikey. >>>>>>>>> >>>>>>>>> Two of those in series, with a TL431 across each one (set for 4.8V or >>>>>>>>> so) to equalize the voltage, plus a charger with about a 50 mA current >>>>>>>>> limit ought to work, I should think. >>>>>>>>> >>>>>>>>> Cheers >>>>>>>>> >>>>>>>>> Phil Hobbs >>>>>>>>> >>>>>>>> >>>>>>>>Is there data on leakage or self-discharge of these beasts? The >>>>>>>>datasheet just says "low leakage current" and this could just mean >>>>>>>>anything... >>>>>>>> >>>>>>>>Pere >>>>>>> >>>>>>>The caps I'm using give the leakage at .16 ma. >>>>>>> >>>>>>>http://www.illinoiscapacitor.com/ic_search/super_products_detail.aspx?icpartnumber=700020 >>>>>> >>>>>> >>>>>>50.625 watt hours???!!! >>>>> >>>>> It's magic, or a decimal point slipped 2 places. 1/2 watt I might >>>>> believe. >>>> >>>>more like 3 decimal places, 0.5*C*V*V/3600 >>> >>>I agree. Did the math and posted as much on 5/14. >>> >>>I'm thinking they mistakenly used some "one size fits all" or >>>watt-hours per X farads. >>> >>>In a related experiment... I'm temporarily using some Maxwell "D-cell" >>>series caps to power the buoy flasher that got 6 months of use from >>>3-AA alkaline cells, switching to a solar charged, 175 F, 3 V system >>>(using caps that cost $15 each). That system is flashing the strobe, >>>for 8 days on the charge it can get in one day. (cover the solar >>>cells with aluminum foil and wait till it dies). >>> >>>So a pair of the $1.29 50 F caps should easily last a day, or perhaps >>>just use one 50 F and go with 2.5V. (specs on the controller that I'm >>>using says it works down to 2.2V, and it seems to recover and start >>>running it's program from the beginning when the voltage gets to about >>>2V) >>> >>>The buoy that I'm illuminating belongs to the city.. So I have to keep >>>the cost low in case they discover that I've modified the buoy and >>>decide to remove my strobe, or vandals (or Visigoths) make it to that >>>end of the lake and steal or destroy it... >>> >>>It's become a "thing" to tweak the buoy with something different each >>>year. I go kayaking at 3:30 AM to avoid the summer heat, but it's a >>>challenge to find ways to see where I'm going in the dark on a lake >>>that's 2 miles long. >>> >>>Radio beacon? or perhaps a super strobe that I can trigger from 2 >>>miles away? >> >>Tritium light? >> >>Strontium aluminate paint? >> >>Both would be fairly short range visibility. For longer range, why not >>use GPS? > >Tried that too. Got a Magellan "waterproof" little hand-held thingee. >Cost a small fortune and wasn't waterproof enough to take dunking in >water. Since they stopped the extended warranty plan, I stopped >taking it kayaking. It was hard to read too... > >The nice thing about it was when I was on a new creek, I could see my >progress.There are some cool cmos-sensor night vision cams around these days, not expensive. We use one to film wildlife in the back yard at night, skunks and cats and raccoons and things. But they are not as sensitive as a real microchannel multiplier, and mostly not waterpoof. -- John Larkin Highland Technology, Inc lunatic fringe electronics
Reply by ●May 19, 20172017-05-19
On Fri, 19 May 2017 10:03:02 -0700, John Larkin <jjlarkin@highlandtechnology.com> wrote:>On Fri, 19 May 2017 06:55:25 -0400, default <default@defaulter.net> >wrote: > >>On Thu, 18 May 2017 08:43:17 -0700, John Larkin >><jjlarkin@highlandtechnology.com> wrote: >> >>>On Thu, 18 May 2017 07:41:04 -0400, default <default@defaulter.net> >>>wrote: >>> >>>>On 18 May 2017 06:00:58 GMT, Jasen Betts <jasen@xnet.co.nz> wrote: >>>> >>>>>On 2017-05-13, default <default@defaulter.net> wrote: >>>>>> On Sat, 13 May 2017 08:35:23 -0700, John Larkin >>>>>><jjlarkin@highlandtechnology.com> wrote: >>>>>> >>>>>>>On Fri, 12 May 2017 06:47:01 -0400, default <default@defaulter.net> >>>>>>>wrote: >>>>>>> >>>>>>>>On Fri, 12 May 2017 10:47:54 +0200, o pere o <me@somewhere.net> wrote: >>>>>>>> >>>>>>>>>On 11/05/17 00:42, Phil Hobbs wrote: >>>>>>>>>> On 05/10/2017 02:31 PM, John Larkin wrote: >>>>>>>>>>> On Wed, 10 May 2017 09:57:21 -0700, etpm@whidbey.com wrote: >>>>>>>>>>> >>>>>>>>>>>> I have an automatic opening trash can in the kitchen that runs off of >>>>>>>>>>>> batteries. I wanna run it with a wall wart. When the lid opens it >>>>>>>>>>>> draws more power than the 750 mA wall wart I tried using to power it >>>>>>>>>>>> could deliver. This makes sense. I don't want to use a bigger wall >>>>>>>>>>>> wart and I don't want to have betteries in it all the time to provide >>>>>>>>>>>> the current. I'm thinking instead of using a capacitor. If the current >>>>>>>>>>>> and voltage draw as well as the duration to open the lid is measured >>>>>>>>>>>> can that not be used to calculate the minimum size capacitor? And if >>>>>>>>>>>> not excessive maybe a cap that would open the lid three or four times >>>>>>>>>>>> in a row could be used in place of the 6 AA cells it uses now. >>>>>>>>>>>> Reasonable? >>>>>>>>>>>> Thanks, >>>>>>>>>>>> Eric >>>>>>>>>>> >>>>>>>>>>> A conventional cap, no. Maybe a super expensive supercap. >>>>>>>>>>> >>>>>>>>>>> I wouldn't want an electronic trash can. All that cheap, badly >>>>>>>>>>> programmed microprocessor/LCD appliance junk will break in a couple of >>>>>>>>>>> years, and be annoying meanwhile. >>>>>>>>>>> >>>>>>>>>>> *SIX* AA cells? How long do they last? >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>> >>>>>>>>>> A couple of supercaps in series might work fine. For instance, >>>>>>>>>> SCMT22C505MRBA0 AVX CAPACITOR 5F 20% 5V 0.065ohms $5.23000 in onesies >>>>>>>>>> from Digikey. >>>>>>>>>> >>>>>>>>>> Two of those in series, with a TL431 across each one (set for 4.8V or >>>>>>>>>> so) to equalize the voltage, plus a charger with about a 50 mA current >>>>>>>>>> limit ought to work, I should think. >>>>>>>>>> >>>>>>>>>> Cheers >>>>>>>>>> >>>>>>>>>> Phil Hobbs >>>>>>>>>> >>>>>>>>> >>>>>>>>>Is there data on leakage or self-discharge of these beasts? The >>>>>>>>>datasheet just says "low leakage current" and this could just mean >>>>>>>>>anything... >>>>>>>>> >>>>>>>>>Pere >>>>>>>> >>>>>>>>The caps I'm using give the leakage at .16 ma. >>>>>>>> >>>>>>>>http://www.illinoiscapacitor.com/ic_search/super_products_detail.aspx?icpartnumber=700020 >>>>>>> >>>>>>> >>>>>>>50.625 watt hours???!!! >>>>>> >>>>>> It's magic, or a decimal point slipped 2 places. 1/2 watt I might >>>>>> believe. >>>>> >>>>>more like 3 decimal places, 0.5*C*V*V/3600 >>>> >>>>I agree. Did the math and posted as much on 5/14. >>>> >>>>I'm thinking they mistakenly used some "one size fits all" or >>>>watt-hours per X farads. >>>> >>>>In a related experiment... I'm temporarily using some Maxwell "D-cell" >>>>series caps to power the buoy flasher that got 6 months of use from >>>>3-AA alkaline cells, switching to a solar charged, 175 F, 3 V system >>>>(using caps that cost $15 each). That system is flashing the strobe, >>>>for 8 days on the charge it can get in one day. (cover the solar >>>>cells with aluminum foil and wait till it dies). >>>> >>>>So a pair of the $1.29 50 F caps should easily last a day, or perhaps >>>>just use one 50 F and go with 2.5V. (specs on the controller that I'm >>>>using says it works down to 2.2V, and it seems to recover and start >>>>running it's program from the beginning when the voltage gets to about >>>>2V) >>>> >>>>The buoy that I'm illuminating belongs to the city.. So I have to keep >>>>the cost low in case they discover that I've modified the buoy and >>>>decide to remove my strobe, or vandals (or Visigoths) make it to that >>>>end of the lake and steal or destroy it... >>>> >>>>It's become a "thing" to tweak the buoy with something different each >>>>year. I go kayaking at 3:30 AM to avoid the summer heat, but it's a >>>>challenge to find ways to see where I'm going in the dark on a lake >>>>that's 2 miles long. >>>> >>>>Radio beacon? or perhaps a super strobe that I can trigger from 2 >>>>miles away? >>> >>>Tritium light? >>> >>>Strontium aluminate paint? >>> >>>Both would be fairly short range visibility. For longer range, why not >>>use GPS? >> >>Tried that too. Got a Magellan "waterproof" little hand-held thingee. >>Cost a small fortune and wasn't waterproof enough to take dunking in >>water. Since they stopped the extended warranty plan, I stopped >>taking it kayaking. It was hard to read too... >> >>The nice thing about it was when I was on a new creek, I could see my >>progress. > >There are some cool cmos-sensor night vision cams around these days, >not expensive. We use one to film wildlife in the back yard at night, >skunks and cats and raccoons and things. But they are not as sensitive >as a real microchannel multiplier, and mostly not waterpoof.I'd love to have a small light waterproof camera to attach to my kite when kite-yaking. Daylight is good enough for that, I only used the kite twice in the dark and hundreds of times in daylight. Small and lightweight are easy enough but waterproof is a whole 'nother thing.
Reply by ●May 19, 20172017-05-19
On Fri, 19 May 2017 12:08:46 -0400, rickman <gnuarm@gmail.com> wrote:>On 5/19/2017 6:55 AM, default wrote: >> On Thu, 18 May 2017 08:43:17 -0700, John Larkin >> <jjlarkin@highlandtechnology.com> wrote: >> >>> On Thu, 18 May 2017 07:41:04 -0400, default <default@defaulter.net> >>> wrote: >>> >>>> On 18 May 2017 06:00:58 GMT, Jasen Betts <jasen@xnet.co.nz> wrote: >>>> >>>>> On 2017-05-13, default <default@defaulter.net> wrote: >>>>>> On Sat, 13 May 2017 08:35:23 -0700, John Larkin >>>>>> <jjlarkin@highlandtechnology.com> wrote: >>>>>> >>>>>>> On Fri, 12 May 2017 06:47:01 -0400, default <default@defaulter.net> >>>>>>> wrote: >>>>>>> >>>>>>>> On Fri, 12 May 2017 10:47:54 +0200, o pere o <me@somewhere.net> wrote: >>>>>>>> >>>>>>>>> On 11/05/17 00:42, Phil Hobbs wrote: >>>>>>>>>> On 05/10/2017 02:31 PM, John Larkin wrote: >>>>>>>>>>> On Wed, 10 May 2017 09:57:21 -0700, etpm@whidbey.com wrote: >>>>>>>>>>> >>>>>>>>>>>> I have an automatic opening trash can in the kitchen that runs off of >>>>>>>>>>>> batteries. I wanna run it with a wall wart. When the lid opens it >>>>>>>>>>>> draws more power than the 750 mA wall wart I tried using to power it >>>>>>>>>>>> could deliver. This makes sense. I don't want to use a bigger wall >>>>>>>>>>>> wart and I don't want to have betteries in it all the time to provide >>>>>>>>>>>> the current. I'm thinking instead of using a capacitor. If the current >>>>>>>>>>>> and voltage draw as well as the duration to open the lid is measured >>>>>>>>>>>> can that not be used to calculate the minimum size capacitor? And if >>>>>>>>>>>> not excessive maybe a cap that would open the lid three or four times >>>>>>>>>>>> in a row could be used in place of the 6 AA cells it uses now. >>>>>>>>>>>> Reasonable? >>>>>>>>>>>> Thanks, >>>>>>>>>>>> Eric >>>>>>>>>>> >>>>>>>>>>> A conventional cap, no. Maybe a super expensive supercap. >>>>>>>>>>> >>>>>>>>>>> I wouldn't want an electronic trash can. All that cheap, badly >>>>>>>>>>> programmed microprocessor/LCD appliance junk will break in a couple of >>>>>>>>>>> years, and be annoying meanwhile. >>>>>>>>>>> >>>>>>>>>>> *SIX* AA cells? How long do they last? >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>> >>>>>>>>>> A couple of supercaps in series might work fine. For instance, >>>>>>>>>> SCMT22C505MRBA0 AVX CAPACITOR 5F 20% 5V 0.065ohms $5.23000 in onesies >>>>>>>>>> from Digikey. >>>>>>>>>> >>>>>>>>>> Two of those in series, with a TL431 across each one (set for 4.8V or >>>>>>>>>> so) to equalize the voltage, plus a charger with about a 50 mA current >>>>>>>>>> limit ought to work, I should think. >>>>>>>>>> >>>>>>>>>> Cheers >>>>>>>>>> >>>>>>>>>> Phil Hobbs >>>>>>>>>> >>>>>>>>> >>>>>>>>> Is there data on leakage or self-discharge of these beasts? The >>>>>>>>> datasheet just says "low leakage current" and this could just mean >>>>>>>>> anything... >>>>>>>>> >>>>>>>>> Pere >>>>>>>> >>>>>>>> The caps I'm using give the leakage at .16 ma. >>>>>>>> >>>>>>>> http://www.illinoiscapacitor.com/ic_search/super_products_detail.aspx?icpartnumber=700020 >>>>>>> >>>>>>> >>>>>>> 50.625 watt hours???!!! >>>>>> >>>>>> It's magic, or a decimal point slipped 2 places. 1/2 watt I might >>>>>> believe. >>>>> >>>>> more like 3 decimal places, 0.5*C*V*V/3600 >>>> >>>> I agree. Did the math and posted as much on 5/14. >>>> >>>> I'm thinking they mistakenly used some "one size fits all" or >>>> watt-hours per X farads. >>>> >>>> In a related experiment... I'm temporarily using some Maxwell "D-cell" >>>> series caps to power the buoy flasher that got 6 months of use from >>>> 3-AA alkaline cells, switching to a solar charged, 175 F, 3 V system >>>> (using caps that cost $15 each). That system is flashing the strobe, >>>> for 8 days on the charge it can get in one day. (cover the solar >>>> cells with aluminum foil and wait till it dies). >>>> >>>> So a pair of the $1.29 50 F caps should easily last a day, or perhaps >>>> just use one 50 F and go with 2.5V. (specs on the controller that I'm >>>> using says it works down to 2.2V, and it seems to recover and start >>>> running it's program from the beginning when the voltage gets to about >>>> 2V) >>>> >>>> The buoy that I'm illuminating belongs to the city.. So I have to keep >>>> the cost low in case they discover that I've modified the buoy and >>>> decide to remove my strobe, or vandals (or Visigoths) make it to that >>>> end of the lake and steal or destroy it... >>>> >>>> It's become a "thing" to tweak the buoy with something different each >>>> year. I go kayaking at 3:30 AM to avoid the summer heat, but it's a >>>> challenge to find ways to see where I'm going in the dark on a lake >>>> that's 2 miles long. >>>> >>>> Radio beacon? or perhaps a super strobe that I can trigger from 2 >>>> miles away? >>> >>> Tritium light? >>> >>> Strontium aluminate paint? >>> >>> Both would be fairly short range visibility. For longer range, why not >>> use GPS? >> >> Tried that too. Got a Magellan "waterproof" little hand-held thingee. >> Cost a small fortune and wasn't waterproof enough to take dunking in >> water. Since they stopped the extended warranty plan, I stopped >> taking it kayaking. It was hard to read too... >> >> The nice thing about it was when I was on a new creek, I could see my >> progress. > >They are rated as waterproof, but not very waterproof. I've yet to find >one that will survive on the deck of a kayak for more than a season. >Sooner or later they leak and crap out. > >I've never had any trouble seeing where I'm going. Even starlight is >enough to navigate. Once the stars are gone you have to know your >terrain (aquaine?) pretty well though. Overcast makes for interesting >trips though. I take you paddle where there is no illumination from >houses and such? Even a single porch light in the distance can provide >orientation.Most days (nearly every day) I paddle to the end of the lake and turn around and come back. There are two large bays jutting off the main lake and one is nearly as long as the main lake. Add a little fog (there have been times where I had no idea where I was) and navigation gets interesting. The houses at the end of the lake make spotting the buoy difficult for their lights and glare. It's nice to be able to make a beeline for the buoy, then I'm sure I cover the same amount of ground each time, and can time my runs. It isn't a matter of life or death, or even important that I see the buoy. But I got interested in how to best find it in the dark, and that's evolved into a fun excuse to tinker with electronics. Then there's the alligators... It's a big lake and there can only be 4-5 gators in it, but on three occasions I managed to surprise sleeping gators - against all odds I would think. There's nothing quite like paddling into a sleeping gator to get one's adrenaline up. And I may know I'm not part of his food chain, but does he know? And those things are so near-sighted they just might take me for another gator impinging on his territory or mate.
