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Barry T Coles Senior Member Joined: 30/07/2009 Location: AustraliaPosts: 109
Posted: 02:34am 25 Jun 2010
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What a thread; it's gone from a show & tell to a technical tusstle & now to turd burglers, what next?
Cheers
Barry I need to learn from the mistakes of others.
I dont have the time to make them all myself.
MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329
Posted: 05:41am 25 Jun 2010
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Crew
I started this mess so I thought I'd add this: In a day when we witnessed the world's longest-on-record Wimbledon tennis match end with it going nowhere, maybe we could make this the world's longest 4m thread that goes nowhere too!
. . . . . MacNothing difficult is ever easy!
Perhaps better stated in the words of Morgan Freeman,
"Where there is no struggle, there is no progress!"
Copeville, Texas
VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539
Posted: 10:36am 25 Jun 2010
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Hi Mack
I disagree on it going nowhere as it has brought out a lot of different points of view and agree or disagree with different points of view the discussion thereof is educational even if only makes members think about what is said then check for themselves or ask more questions,the principals discussed cut to the core of our hobby and understanding them will help members to plan and execute their projects.
It is important also to remember that the "theoretical best way" isn't always the best or most practical, as some times we are forced due to AIDS {acute income deficiency syndrome} a financial consideration to do things as best we can afford using things at hand and, accepting the results as the best we can do with the amount of knowledge /money available.
All the best
BobFoolin Around
MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329
Posted: 04:08pm 25 Jun 2010
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Isn't Barry T Coles' avitar just the best ever?
. . . . . MacNothing difficult is ever easy!
Perhaps better stated in the words of Morgan Freeman,
"Where there is no struggle, there is no progress!"
Copeville, Texas
Barry T Coles Senior Member Joined: 30/07/2009 Location: AustraliaPosts: 109
Posted: 07:08am 26 Jun 2010
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Well said Bob; I couldnt agree more, I've learnt more from this site & this thread about electronics than I ever knew before.
Cheers
BarryI need to learn from the mistakes of others.
I dont have the time to make them all myself.
VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539
Posted: 12:09pm 26 Jun 2010
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Hi Barry
Thanks for the positive comment as a lot are to critical of the effort that is put into the forum by members contributing their time and effort to help, none of us are perfect and we all look at things through our own experience and skills, not all will agree with one another, but it is all a help to other members. If we where all the same it would be a boring world let alone the forum. We often start in a direction to end up going another way so, that means more scenery to see.
Thanks to all those who have contributed to the discussion, we appreciate all your input.
Stay tuned for further disagreements.
All the best
BobFoolin Around
Greenbelt Guru Joined: 11/01/2009 Location: United StatesPosts: 566
Posted: 09:15pm 26 Jun 2010
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Hi GUYS
People from the past, Made the study of electricity a most confusing subject, Their Ego demanded recognition for contribution's to the theory of how it works.
This is Just Theory, No one has physically counted the so called electrons in a theoretical unit with a value assigned by an early experimenter whose name was Pierre Ampere, later English usage Shortened to Amp. or Amper.
Another Fella named, Simon Ohm. experimented with different metals as a conductor of electricity Finally arriving at a value
Alexander Volta, another experimenter, (Worked with batteries)
has defined the volt as the electromotive force required to push
6.28 X 10^18 power electrons Through a resistance of One Ohm past a point in one second. Electro motive Force was the word before VOLT because it did not have a value
assigned.
From the Three values above, all electrical theory evolved.
1 VOLTa X 1 AMPer = 1 James WATT. (Watt is a Power value) any combination of VOLTa multiplied by AMPer that = 746 is one electrical Horse power, Example 100 volts
x 7.46 amp = 746 You can see from this that 1 Kilowatt (1000 Watts) (100 volts multiplied by 10 amps)=1000 is more than 1 horse power.
The Metric system uses the Kilowatt value to specify the power of a engine Petro-Steam-or turbine, Horsepower is used in the US. which is sometimes confusing when deciding on the capabilities of a similar engine. a 100 Horsepower engine will be metric rated at 75 Kilowatts.
when you see the abbreviation MMF Or MFD Or Very rarely FD, It means Ampere or parts of an Amp. The Farrad is a charge meaning a stored quantity of electrons in a Capacitor- condenser is still proper as it was the first name for this electrical device. The Farad is = to the amp x 1 second.6.28 x10^ 18 electrons, 1 MMF is a MICRO-MICRO Farrad a very small fraction of a farrad, an MFD is a Microfarrad, And 1- FD is a Full 1 amp charge and would be a physically large capacitor.
The Henry, another Old Timer fooling around with coils of wire and magnets. when he was able to Induce a current flow of 1 amp in his coil he named it 1 Henry.
Coil chokes and inductors used around the House are rated in Millihenrys or Microhenrys. again a fraction of a full amp.
The COULOMB is also an amp, Just another name for confusion.
Nuff of that,,
BOB used a number of 6.24 x 10^ 18 electrons,
Ross used 6 x 10^ 18 and also 6 x 10^ 8
I used 6.28 x 10^ 18, How in the World will anyone know which is Right, with exception of Nuclear Physicists What big difference does it make??
VK4AYQ wrote: Hi Ross All definitions where taken from the Radio Society of GB handbook edition Three 1965 Probably still refers to capacitors as "Condensers" - a term which is very obsolete. Quote: Unit of Quantity, as an electron is to small for practical use the flow is expressed in coulomb per second and 1 coulomb equals 6 million million million electrons per second flowing in the circuit, and is called an ampere AMP circuit symbol "I" At the risk of sounding smug... this is what sh!ts me to tears... you've quoted something, MISUNDERSTOOD it, and are then trying to pound me over the head with it and you just can't see that you're wrong. "Coulomb per second" One Coulomb is 6x10^18 electrons per second. So you have litterally 6x10^8 electrons / second -------------------------Time has proven that I am blind to the Obvious, some of the above may be True?
grub Senior Member Joined: 27/11/2007 Location: AustraliaPosts: 169
Posted: 09:51pm 26 Jun 2010
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I see it as Volts hurt, Amps kill.
I must have Volts now because my head hurts :(
MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329
Posted: 11:58pm 26 Jun 2010
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Greenbelt
Great history lesson. I'm glad to see there's a good reason for as much confusion as arises from the study of electricity.
There's one fellow you left out of the mix though; MacGyver. His unit of measure is a "goofa". Depending on the exact topic, this can be a decagoofa, centagoofa, kiaogoofa or even a megagoofa! If you think I'm kidding, just ask Oz! I think I used up all his hair and then some just coming to an elementary understanding of induced voltage!
. . . . . Mac Nothing difficult is ever easy!
Perhaps better stated in the words of Morgan Freeman,
"Where there is no struggle, there is no progress!"
Copeville, Texas
Greenbelt Guru Joined: 11/01/2009 Location: United StatesPosts: 566
Posted: 03:50am 27 Jun 2010
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MacGyver;
I'm Very sorry for this unforgivable oversight, I will attempt to make amends by creating a value equivalent for the Goofa. How's this hit Ya.
A goofa is equal to 1 titanic 1 Spruce Goose, Watergate,On and On. a Non fixable event.
A Microgoofa is a violation of Murphy's Law either known or unknown at the Time which does not result in Bodily harm. A millagoofa will cost you money and will require new plans or Mods.
The Megagoofa is a history changing event, The Bombing of Pearl Harbor that resulted in the use of Nuclear Weapons.
Note; It is likely that a new definition for screw up is birthing at this moment. This is a free press and everyone is invited (with Mac's permission) to indulge whenever the thought occurs.---Roe
Time has proven that I am blind to the Obvious, some of the above may be True?
VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539
Posted: 04:19am 27 Jun 2010
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Hi Greenbelt
Thanks for the comments mate , just to clear a point where you quoted me in your previous post part of the quote and part was Ross;s reply to that the part that was mine is included below.
ACTUAL QUOTE
{VK4AYQ wrote: Hi Ross All definitions where taken from the Radio Society of GB handbook edition Three 1965 Probably still refers to capacitors as "Condensers" - a term which is very obsolete. Quote: Unit of Quantity, as an electron is to small for practical use the flow is expressed in coulomb per second and 1 coulomb equals 6 million million million electrons per second flowing in the circuit, and is called an ampere AMP circuit symbol "I"}
Unfortunately due to poor formatting on my part it got combined with Ross;s comment rebutting it. To me it is like calling a car a car or a sedan / motor vehicle.
The point I was making was that there is a actual amount of electrons flowing for 1 second at a EMF of 1 volt to make an AMP, this is to give the concept that there is actually something happening in the conductor while the current is actually flowing.
Also that the resultant Amps x Volts can be read in the circuit on a any instant but as the formula is a time based formula it relates to Ampere hours / minuets / seconds / or even milliseconds.
This then relates to a flow of electrons that increases with increased "I" {Amps} so we can relate what happens when we try to cram more electrons through a conductor.
This then relates to the use of higher voltage on the conductor as we can conduct more energy by increasing the volts E in the circuit.
eg: 12 volt circuit at 10 amps = 120 watts
48 volt circuit at 10 amps = 480 watts
This is for the same current flow of 10 amps so four times the power / energy /watts
for the same resistive loss in the conductor.
It is important to recognize the two factors in the transfer of energy in the wire.
Keep up the good work
All the best
Bob
Foolin Around
VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539
Posted: 04:25am 27 Jun 2010
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Hi Mack
Do Goofa units apply in series or parallel and what is the resistance in the medium that transmits them, and how do you calculate media losses, and does this include the factor of media suppression?
All the best
BobFoolin Around
RossW Guru Joined: 25/02/2006 Location: AustraliaPosts: 495
Posted: 05:59am 27 Jun 2010
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Nothing like calling a car a sedan. Both are motor vehicles.
More like calling thunder lightning. One is an effect of the other, but they're totally different.
OK. *THIS* part is correct. A number of electrons over a period of time is an AMP.
Also no argument.
OK, you're running off the rails here. There is no such thing as "ampere hours" in the context of current flow, and it's an almost meaningless figure for energy unless the voltage is also specified/known.
The main point you seem to be missing, and keep picking on me for harping on at (and you conveniently gloss over it with a wave of the hand and say "same thing" - is that amps DOES NOT have any time period associated.
I don't know what your maths is like. I attempted to show you this before but you either didn't see it or chose to ignore it (there was no acknowledgement either way) - and that is that the flow of electrons over a given time (in this case, as you said, 6 million million million in one second) is the definition of CHARGE - 1 coulomb.
The Amp (flow) is defined as one coulomb (charge) per second. So write it out.
The charge (1 coulomb) is a "number of electrons per second" which you are then dividing by seconds. The seconds simply cancel in the calculation, and you end up with Amps as a unit, it has no time.
I don't want a full-on battle over this, but it's a critical fundamental of electricity, and if people learn your "amps per second" they're going to find other parts very confusing, especially when we start adding things like amp-hours, watt-hours etc.Edited by RossW 2010-06-28
Greenbelt Guru Joined: 11/01/2009 Location: United StatesPosts: 566
Posted: 06:56am 27 Jun 2010
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VK4AYQ;
You are absolutely correct The Italics are the post made by rossJ who was Quoting and Replying to your post. I had planned to separate the parts But (BLAMES THE WIFE)I was Called to dinner, Its Eat now or forever fix your own eh. In a hurried state I posted and then of course remembered Too Late,,
After dinner a new post voided my chance to Edit. Sorry Mate , will try to do better.
Perhaps we should Return to the basic thread with a Comparative analysis of solar Thermal vs. Solar cells.
A refrigerant is needed that has a boiling point Temperature of 55-60D C. The temperature of Thermal solar collectors could produce a reasonable pressure when operating 40 degrees cooler than boiling Water and the refrigerant would condense at ambient temperature in a proper Radiator.
The boiling point Of Gasoline is close to this number so should be possible to formulate a suitable liquid to operate in a sealed Turbine-generator unit ?
1100-1300 Watts. sq. meter Solar Radiation. A solar Panel 1 square meter at 20 percent efficiency would need to output 220 watts. Something Not Right Here ?
Time has proven that I am blind to the Obvious, some of the above may be True?
RossW Guru Joined: 25/02/2006 Location: AustraliaPosts: 495
Posted: 07:32am 27 Jun 2010
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Average Solar Insolation over a year at the earths surface is usually quoted as close enough to 1000W/sqm
20% efficiency for an entire module is a little optomistic for most. Cell efficiencies are higher than entire modules because of the space thats usually wasted around cells, frames etc.
My "100W" modules are 1200 x 670mm, which is 0.8 sq m.
At 14% (cell) conversion efficiency (fairly typical), I'd expect 112 watts out.
Including wasted space, around 12.5% is what I'd expect, and that's exactly 100W
(Your 1300W above is about right for solar radiation at the top of the atmosphere, from memory)
VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539
Posted: 07:52am 27 Jun 2010
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Hi Ross
Welcome back mate good to have you back on line.
Hi Greenbelt
No worries Mate, Ross is back on line too so that,s good he can throw rocks at me and visa versa to keep up the interest.
On your solar panel efficiency point, the table I have is an average power per sq mtr of 1000 watts {per hour} but when you take into account the angular differences during the day this is debatable and the panels are rated at Lab conditions not real ones. and the best of them in production do 16%, there are other developmental cells that do better but not seen on the market at the moment.
On your idea with the sealed unit I had one of these running 35 years ago but at the time there was no demand for it commercially, as power was too cheeep.
I used freon 22 as the gas medium and a steam type motor I made that lived in a sealed box with the output shaft coming out through a fridge shaft seal, it was a sealed unit with the oil and gas combined. It also worked on Propane gas not quite as efficient but more practical.
It had 6 sq mtr approx of conventional solar collectors as pre heat and 8 sq mtr approx of trough collector heating the storage medium, I achieved a storage medium temperature of 320 deg C. it collected enough energy to run four hours after sunset, as that was the object, it would run longer but degraded the storage media temperature to much, it had a 5kwa dc generator charging the batteries, with a few solar panels to run the accessories as a backup. It wasn't running at full power all the time as it depended on the state of the batteries as to its output.
Reason for using DC I had the generator, and not so critical on governor speed as that was in the box and a bit hard to adjust without loosing gas. It was designed to run a rural property and concentrated on mechanical device as solar panels cost a fortune in those days.
Most farms had diesel generators as distillate was cheap also from memory about 35 cents a gallon to rural producers.
The good old days, I might do a small one someday just for fun if I get all my other projects under control.
All the best
Bob
Foolin Around
VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539
Posted: 08:01am 27 Jun 2010
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Hi Ross
I have found the same results with my cells as you have and without MPPT regulator, around 80% of panel rating, they are 170 watt panels noncrystalline. I have several 200 watt panels on test that are actually exceeding ratings at midday at 48 deg inclination to the north, bit odd but that's the best angle, may be caused by refraction in the atmosphere, temperature 56 deg C.
All the best
BobFoolin Around
neil0mac Senior Member Joined: 26/12/2009 Location: AustraliaPosts: 210
Posted: 09:18am 27 Jun 2010
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Keeping an eye on ... http://www.bom.gov.au/sat/solrad.shtml ... periodically, during different climatic conditions, will give a reasonably good idea of irradiation over a year. (Other bureaus provide a similar service?)Edited by neil0mac 2010-06-28
RossW Guru Joined: 25/02/2006 Location: AustraliaPosts: 495
Posted: 10:33am 27 Jun 2010
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ARGGGHHHHH!!!!
Watts = volts times amps
Volts is an instantaneous figure, as is Amps.
WATTS is therefore also instantaneous.
Solar insolation of 1000 watts/sqm is therefore 1000 watts per square metre PERIOD.
It is not per hour, per minute, per second or per day. It's 1000 watts per square metre.
oztules Guru Joined: 26/07/2007 Location: AustraliaPosts: 1686
Posted: 10:41am 27 Jun 2010
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Bob,
Now you have made me think about it.
Instinctively, I feel amps are the number of electrons passing a point in a circuit. The problem is I don't know for sure if the electrons actually move, or it is a wave type motion, and we apply force to one of them that they push on the one next to them and the one next to them, and so on till the one at the end gets pushed out the end..... I suppose it is in effect the same thing perhaps.
This would still imply a flow rate analogy..... (sorry Ross)
If it was electron number over time (amp), then a volume of electrons (say a coulomb) ....... egad I'll start again.....
Let me look at this in my own twisted little way.
So, it is looking like a volume (say a litre) of electrons is a coulomb (quantity) thing, but to get to that volume there, we need a flow rate to fill the liter container in the first place.... So we get them from another litre container next to them. Now we have to get them there, so we push them with potential, and they run through a tunnel into the empty container.
Now we measure this flow rate in amps, but it is looking to me as I type this, that that is a measure of numbers of electrons trying to get through the tunnel. The rate they get through I would see measured in electrons per time (amp)....An amp is a coulomb of electrons per second.... or a volume/time = a rate... things are looking up.
I look back at this and see I said number of electrons getting through....
This makes some sort of weird sense. If time=0 then flow=0..... =true... the flow is zero, so the amps=0 ...... Hmmmm..
So amps are a rate of flow past a point (eg 1 coulomb per second= 1 amp), then this has to be electrons/second If we get that and multiply that by time.... we get the number that have made it through.
So 6.23x10^18 electrons per second, passing a point, deposits 1 coulomb of electrons in one second.
This satisfies the problem for me. I have a flow rate (units(or coulombs)/T) and a Time T so:
(Units/Time) X Time=Units (Coulomb).... or Amps X Time = Coulombs or Amps =Coulombs/Time or Time=Coulombs/Amps
Plumbing analogy does work here for me.
So I think amps are time based, they are Coulombs/second.
.............oztules
(Gosh I have a twisted mind)Village idiot...or... just another hack out of his depth
Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
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