On 05/11/2017 04:07 PM, John Larkin wrote:> On Wed, 10 May 2017 13:50:05 -0700, etpm@whidbey.com wrote: > >> On Wed, 10 May 2017 11:31:40 -0700, John Larkin >> <jjlarkin@highland_snip_technology.com> 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? >> Thanks for the quick responses everyone. It looks like rechargeable >> cells are really the best way to go. The regular cells last about 3 >> months. I hate the garbage can. I hate throwing batteries in the >> recycle bin. I hate the garbage can. It was advertised as motion >> sensitive. It is not. It senses reflected IR, not motion. So if the >> damn sensor is covered with IR reflective material the lid stays open. >> Did you know that some clear plastic sheet reflects IR? Did I say I >> hate the garbage can? Unfortunately for now it is the best solution. >> Though a foot operated model is in the future right now it just won't >> work. >> Thanks Again, >> Eric > > We have a nice kitchen trash can that opens when you step on a little > pedal thing. > > Would someone there have a problem with the mechanical version? > Wheelchair or something? > > For a serious engineering project, throw away the electronics and > drive the lid motor yourself.Sure! Use a Cortex M4 and the OP can have a trash can that has to be rebooted periodically! O tempora! O mores! Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
Is this scheme reasonable?
Started by ●May 10, 2017
Reply by ●May 13, 20172017-05-13
Reply by ●May 13, 20172017-05-13
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. Damn good caps for what I'm doing with them though...
Reply by ●May 13, 20172017-05-13
On Thu, 11 May 2017 13:10:36 -0400, rickman wrote:> On 5/11/2017 11:32 AM, Tim Wescott wrote: >> On Wed, 10 May 2017 18:13:26 -0400, rickman wrote: >> >>> On 5/10/2017 1:52 PM, Tim Wescott wrote: >>>> On Wed, 10 May 2017 09:57:21 -0700, etpm 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 >>>> >>>> This is kind of a repeat of what Rick said, from a different point of >>>> view: >>>> >>>> For the amount of energy stored, caps are BIG. And a capacitor's >>>> voltage falls as it delivers energy -- by definition. If it doesn't, >>>> it's not a capacitor. >>>> >>>> Rechargeable batteries are much smaller than caps -- and it's what >>>> the thing's designed for anyway. The easiest thing to do, which >>>> should be reliable, is to populate the battery tray with rechargable >>>> NiMH cells, then put a charger on it that runs at a trickle rate >>>> (i.e., 50mA for every 1000mAh of capacity). That _should_ let the >>>> batteries last a good long time, but whether it'll stay charged is >>>> kind of up in the air (or maybe it'll work fin normally but not on >>>> Thanksgiving or Christmas). >>>> >>>> Make the charger from a wall-wart and a resistor. >>>> >>>> The only other way I can think of to make this work "better" is with >>>> a smart charger -- and then you're messing with some pretty fancy >>>> electronics to keep the batteries happy. So -- probably not a good >>>> idea. >>>> >>>> Finally -- have you considered an old fashioned, works just fine, >>>> _mechanical_ covered trash can? >>> >>> I think you have this pretty much backwards. A "smart" battery >>> charger is the only real way to go if you want the batteries to last. >>> The "trickle" charger may keep the batteries up given that most people >>> don't use such a trash can for long periods, but once rechargeables >>> are charged, they don't want more current unless they are lead acid. >>> I didn't look it up, so do you know that NiMH will take a trickle >>> charge without damage? I don't think I've heard of that. >>> >>> Proper charging electronics doesn't need to be hard to design or use. >> >> I know Eric from these groups, and I'm assuming that he doesn't want to >> run out and design a PCB just for a trash can. > > You seem to be unable to think outside the box many times. I can't > imagine building a PCB for a project like this. I'd use an expression > involving cats, but it is prohibited in this house.So what specific suggestion do you have, oh master of practicality? -- www.wescottdesign.com
Reply by ●May 13, 20172017-05-13
On 5/13/2017 2:26 PM, Tim Wescott wrote:> On Thu, 11 May 2017 13:10:36 -0400, rickman wrote: > >> On 5/11/2017 11:32 AM, Tim Wescott wrote: >>> On Wed, 10 May 2017 18:13:26 -0400, rickman wrote: >>> >>>> On 5/10/2017 1:52 PM, Tim Wescott wrote: >>>>> On Wed, 10 May 2017 09:57:21 -0700, etpm 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 >>>>> >>>>> This is kind of a repeat of what Rick said, from a different point of >>>>> view: >>>>> >>>>> For the amount of energy stored, caps are BIG. And a capacitor's >>>>> voltage falls as it delivers energy -- by definition. If it doesn't, >>>>> it's not a capacitor. >>>>> >>>>> Rechargeable batteries are much smaller than caps -- and it's what >>>>> the thing's designed for anyway. The easiest thing to do, which >>>>> should be reliable, is to populate the battery tray with rechargable >>>>> NiMH cells, then put a charger on it that runs at a trickle rate >>>>> (i.e., 50mA for every 1000mAh of capacity). That _should_ let the >>>>> batteries last a good long time, but whether it'll stay charged is >>>>> kind of up in the air (or maybe it'll work fin normally but not on >>>>> Thanksgiving or Christmas). >>>>> >>>>> Make the charger from a wall-wart and a resistor. >>>>> >>>>> The only other way I can think of to make this work "better" is with >>>>> a smart charger -- and then you're messing with some pretty fancy >>>>> electronics to keep the batteries happy. So -- probably not a good >>>>> idea. >>>>> >>>>> Finally -- have you considered an old fashioned, works just fine, >>>>> _mechanical_ covered trash can? >>>> >>>> I think you have this pretty much backwards. A "smart" battery >>>> charger is the only real way to go if you want the batteries to last. >>>> The "trickle" charger may keep the batteries up given that most people >>>> don't use such a trash can for long periods, but once rechargeables >>>> are charged, they don't want more current unless they are lead acid. >>>> I didn't look it up, so do you know that NiMH will take a trickle >>>> charge without damage? I don't think I've heard of that. >>>> >>>> Proper charging electronics doesn't need to be hard to design or use. >>> >>> I know Eric from these groups, and I'm assuming that he doesn't want to >>> run out and design a PCB just for a trash can. >> >> You seem to be unable to think outside the box many times. I can't >> imagine building a PCB for a project like this. I'd use an expression >> involving cats, but it is prohibited in this house. > > So what specific suggestion do you have, oh master of practicality?Really? You can't think of any board which could be bought to do this? Or a prototype can be made by any of many choices which don't require a PCB to be made. Do you really need a tutorial? This is a one off and a fairly simple circuit. Not something that requires a custom PCB really. -- Rick C
Reply by ●May 13, 20172017-05-13
On Sat, 13 May 2017 14:31:09 -0400, rickman wrote:> On 5/13/2017 2:26 PM, Tim Wescott wrote: >> On Thu, 11 May 2017 13:10:36 -0400, rickman wrote: >> >>> On 5/11/2017 11:32 AM, Tim Wescott wrote: >>>> On Wed, 10 May 2017 18:13:26 -0400, rickman wrote: >>>> >>>>> On 5/10/2017 1:52 PM, Tim Wescott wrote: >>>>>> On Wed, 10 May 2017 09:57:21 -0700, etpm 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 >>>>>> >>>>>> This is kind of a repeat of what Rick said, from a different point >>>>>> of view: >>>>>> >>>>>> For the amount of energy stored, caps are BIG. And a capacitor's >>>>>> voltage falls as it delivers energy -- by definition. If it >>>>>> doesn't, >>>>>> it's not a capacitor. >>>>>> >>>>>> Rechargeable batteries are much smaller than caps -- and it's what >>>>>> the thing's designed for anyway. The easiest thing to do, which >>>>>> should be reliable, is to populate the battery tray with >>>>>> rechargable NiMH cells, then put a charger on it that runs at a >>>>>> trickle rate (i.e., 50mA for every 1000mAh of capacity). That >>>>>> _should_ let the batteries last a good long time, but whether it'll >>>>>> stay charged is kind of up in the air (or maybe it'll work fin >>>>>> normally but not on Thanksgiving or Christmas). >>>>>> >>>>>> Make the charger from a wall-wart and a resistor. >>>>>> >>>>>> The only other way I can think of to make this work "better" is >>>>>> with a smart charger -- and then you're messing with some pretty >>>>>> fancy electronics to keep the batteries happy. So -- probably not >>>>>> a good idea. >>>>>> >>>>>> Finally -- have you considered an old fashioned, works just fine, >>>>>> _mechanical_ covered trash can? >>>>> >>>>> I think you have this pretty much backwards. A "smart" battery >>>>> charger is the only real way to go if you want the batteries to >>>>> last. The "trickle" charger may keep the batteries up given that >>>>> most people don't use such a trash can for long periods, but once >>>>> rechargeables are charged, they don't want more current unless they >>>>> are lead acid. I didn't look it up, so do you know that NiMH will >>>>> take a trickle charge without damage? I don't think I've heard of >>>>> that. >>>>> >>>>> Proper charging electronics doesn't need to be hard to design or >>>>> use. >>>> >>>> I know Eric from these groups, and I'm assuming that he doesn't want >>>> to run out and design a PCB just for a trash can. >>> >>> You seem to be unable to think outside the box many times. I can't >>> imagine building a PCB for a project like this. I'd use an expression >>> involving cats, but it is prohibited in this house. >> >> So what specific suggestion do you have, oh master of practicality? > > Really? You can't think of any board which could be bought to do this? > Or a prototype can be made by any of many choices which don't require a > PCB to be made. Do you really need a tutorial? > > This is a one off and a fairly simple circuit. Not something that > requires a custom PCB really.Well, if it's so damned easy, provide the tutorial just to spite me! It'll help Eric, which is _my_ goal. Part numbers! Ebay links! C'mon -- you yourself say it's a snap! What does it mean to say "oh that's easy, stupid!" and then refuse to demonstrate? -- www.wescottdesign.com
Reply by ●May 13, 20172017-05-13
On 5/13/2017 2:42 PM, Tim Wescott wrote:> On Sat, 13 May 2017 14:31:09 -0400, rickman wrote: > >> On 5/13/2017 2:26 PM, Tim Wescott wrote: >>> On Thu, 11 May 2017 13:10:36 -0400, rickman wrote: >>> >>>> On 5/11/2017 11:32 AM, Tim Wescott wrote: >>>>> On Wed, 10 May 2017 18:13:26 -0400, rickman wrote: >>>>> >>>>>> On 5/10/2017 1:52 PM, Tim Wescott wrote: >>>>>>> On Wed, 10 May 2017 09:57:21 -0700, etpm 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 >>>>>>> >>>>>>> This is kind of a repeat of what Rick said, from a different point >>>>>>> of view: >>>>>>> >>>>>>> For the amount of energy stored, caps are BIG. And a capacitor's >>>>>>> voltage falls as it delivers energy -- by definition. If it >>>>>>> doesn't, >>>>>>> it's not a capacitor. >>>>>>> >>>>>>> Rechargeable batteries are much smaller than caps -- and it's what >>>>>>> the thing's designed for anyway. The easiest thing to do, which >>>>>>> should be reliable, is to populate the battery tray with >>>>>>> rechargable NiMH cells, then put a charger on it that runs at a >>>>>>> trickle rate (i.e., 50mA for every 1000mAh of capacity). That >>>>>>> _should_ let the batteries last a good long time, but whether it'll >>>>>>> stay charged is kind of up in the air (or maybe it'll work fin >>>>>>> normally but not on Thanksgiving or Christmas). >>>>>>> >>>>>>> Make the charger from a wall-wart and a resistor. >>>>>>> >>>>>>> The only other way I can think of to make this work "better" is >>>>>>> with a smart charger -- and then you're messing with some pretty >>>>>>> fancy electronics to keep the batteries happy. So -- probably not >>>>>>> a good idea. >>>>>>> >>>>>>> Finally -- have you considered an old fashioned, works just fine, >>>>>>> _mechanical_ covered trash can? >>>>>> >>>>>> I think you have this pretty much backwards. A "smart" battery >>>>>> charger is the only real way to go if you want the batteries to >>>>>> last. The "trickle" charger may keep the batteries up given that >>>>>> most people don't use such a trash can for long periods, but once >>>>>> rechargeables are charged, they don't want more current unless they >>>>>> are lead acid. I didn't look it up, so do you know that NiMH will >>>>>> take a trickle charge without damage? I don't think I've heard of >>>>>> that. >>>>>> >>>>>> Proper charging electronics doesn't need to be hard to design or >>>>>> use. >>>>> >>>>> I know Eric from these groups, and I'm assuming that he doesn't want >>>>> to run out and design a PCB just for a trash can. >>>> >>>> You seem to be unable to think outside the box many times. I can't >>>> imagine building a PCB for a project like this. I'd use an expression >>>> involving cats, but it is prohibited in this house. >>> >>> So what specific suggestion do you have, oh master of practicality? >> >> Really? You can't think of any board which could be bought to do this? >> Or a prototype can be made by any of many choices which don't require a >> PCB to be made. Do you really need a tutorial? >> >> This is a one off and a fairly simple circuit. Not something that >> requires a custom PCB really. > > Well, if it's so damned easy, provide the tutorial just to spite me! > It'll help Eric, which is _my_ goal. > > Part numbers! Ebay links! C'mon -- you yourself say it's a snap! > > What does it mean to say "oh that's easy, stupid!" and then refuse to > demonstrate?Why are you so upset? You said it required making a PCB and I said it doesn't. Now I have to go out and build the damn thing to prove my point? You are a trip. At this point you are just trolling. -- Rick C
Reply by ●May 13, 20172017-05-13
On Sat, 13 May 2017 14:44:27 -0400, rickman wrote:> On 5/13/2017 2:42 PM, Tim Wescott wrote: >> On Sat, 13 May 2017 14:31:09 -0400, rickman wrote: >> >>> On 5/13/2017 2:26 PM, Tim Wescott wrote: >>>> On Thu, 11 May 2017 13:10:36 -0400, rickman wrote: >>>> >>>>> On 5/11/2017 11:32 AM, Tim Wescott wrote: >>>>>> On Wed, 10 May 2017 18:13:26 -0400, rickman wrote: >>>>>> >>>>>>> On 5/10/2017 1:52 PM, Tim Wescott wrote:>>>>>>> Proper charging electronics doesn't need to be hard to design or >>>>>>> use.>>> This is a one off and a fairly simple circuit. Not something that >>> requires a custom PCB really. >> >> Well, if it's so damned easy, provide the tutorial just to spite me! >> It'll help Eric, which is _my_ goal. >> >> Part numbers! Ebay links! C'mon -- you yourself say it's a snap! >> >> What does it mean to say "oh that's easy, stupid!" and then refuse to >> demonstrate? > > Why are you so upset? You said it required making a PCB and I said it > doesn't. Now I have to go out and build the damn thing to prove my > point? You are a trip. > > At this point you are just trolling.I'm not upset. I'm amused. But it's really time to put your money where your mouth is, dude, and show how you can do this. Because -- by your own words it's not hard. And it'll benefit _everyone_. Just a block diagram of a charger that's more intelligent than a wall- wart and a resistor (because that's what a trickle charger is). Or a product he can buy that'll do it. That's all -- no need to show us how to implement it sans PCB. -- www.wescottdesign.com
Reply by ●May 13, 20172017-05-13
On 5/13/2017 3:28 PM, Tim Wescott wrote:> On Sat, 13 May 2017 14:44:27 -0400, rickman wrote: > >> On 5/13/2017 2:42 PM, Tim Wescott wrote: >>> On Sat, 13 May 2017 14:31:09 -0400, rickman wrote: >>> >>>> On 5/13/2017 2:26 PM, Tim Wescott wrote: >>>>> On Thu, 11 May 2017 13:10:36 -0400, rickman wrote: >>>>> >>>>>> On 5/11/2017 11:32 AM, Tim Wescott wrote: >>>>>>> On Wed, 10 May 2017 18:13:26 -0400, rickman wrote: >>>>>>> >>>>>>>> On 5/10/2017 1:52 PM, Tim Wescott wrote: > >>>>>>>> Proper charging electronics doesn't need to be hard to design or >>>>>>>> use. > > >>>> This is a one off and a fairly simple circuit. Not something that >>>> requires a custom PCB really. >>> >>> Well, if it's so damned easy, provide the tutorial just to spite me! >>> It'll help Eric, which is _my_ goal. >>> >>> Part numbers! Ebay links! C'mon -- you yourself say it's a snap! >>> >>> What does it mean to say "oh that's easy, stupid!" and then refuse to >>> demonstrate? >> >> Why are you so upset? You said it required making a PCB and I said it >> doesn't. Now I have to go out and build the damn thing to prove my >> point? You are a trip. >> >> At this point you are just trolling. > > I'm not upset. I'm amused. > > But it's really time to put your money where your mouth is, dude, and > show how you can do this. Because -- by your own words it's not hard. > And it'll benefit _everyone_. > > Just a block diagram of a charger that's more intelligent than a wall- > wart and a resistor (because that's what a trickle charger is). Or a > product he can buy that'll do it. That's all -- no need to show us how > to implement it sans PCB.Get me the trash can. -- Rick C
Reply by ●May 13, 20172017-05-13
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
Reply by ●May 14, 20172017-05-14
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. .05625WhOops ... .50625 ... there's your 1/2Wh "default"
