David Icke's Official Forums The 52-year-old pantry lightbulbs

30-12-2011, 05:36 AM   #21
apollo_gnomon
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Readers of this thread (heck, this whole subforum!) may find the following book useful:

The cover makes the book appear boring and serious, but it's written for young readers and has smiley-face electrons inside. It explains basic electricity and electronics quite well and has fun, simple projects, many of which are useful on the hobby electronics bench. I'm on my 3rd copy, as I find it a wonderful reference. I keep giving mine away, then want to look something up in it, usually Mims' version of hand drawn schematic symbols or a 555 timer.

Frankly, I think it should be required reading for anyone born after 1937.

Quote:
 Originally Posted by pi3141 Lightbulbs generally only blow either when transitioning from cold (off) to hot (on) or when a 'ripple current' propogates through the mains network and momentarily takes the voltage higher than it should be - say 245 volts instead of 240 volts. This is the 'over voltage' I wrote about and blows the lightbulb like a fuse. Lightbulbs are 'rated' at 240 volts so a momentary increase in voltage causes it to blow.
Only partially true. If you research AC voltage, you'll find the "rated" voltage to be Root-mean-square rather than peak voltage. Peak volts can run quite a bit higher than listed RMS for your area (120vac, here, but I've read peaks of 145 on the oscilloscope, and still well within spec at RMS).

As I mentioned up-thread, the end-of-lifecycle cause of failure in incandescent lamps is evaporation of the filament. When the glass envelope gets dark, that's filament metal condensing on the glass. Halogen lamps have gas that prevents the evaporated metal from condensing on the glass, so instead it condenses back on the filament. In that case, the filament gets progressively more brittle as more and more metal is in a crystalline structure rather than unstructured (and more flexible) drawn wire.

Quote:
 So its obvious by reducing the voltage from 240 volts to 120 volts (using the diode to perform half wave rectification and thus reduce the input power from 240 volts to 120 volts) even with a huge ripple current the volts will never go over 240 volts so the bulb will never blow.
Uh, no. Alternating current swings between + 120 (240) across 0v and down to - 120 (240).

Positive vs. negative voltage is irrelevant to resistive loads.

Quote:
 However that means you will only get half the light out - so a 100 watt bulb will give 50 watts of light. Hence if you want 80 watts of light you use a 160 watt lightbulb. If you want a 100 watt light source you need to get the manufacturers to make a 200 watt bulb rated for 240 volts and run it at 120 volts. Hence it is obvious, it really is just a matter of making the rating higher. In theory, they could produce a 160 watt lightbulb rated at 280 volts, then the bulb would not break unless it blows when being switched on.
This statement is approximately correct, but not for the reason you think.

With one diode you get half-wave rectified voltage. I don't know if LED Christmas lights are infesting your area the way they are here, but if they are you might have noticed they tend to strobe when you see them out of the corner of your eye or as you drive past, but not when you look at them straight. That's because those strings of lights are driven by ac passed through one diode. Theeffect keeps us from noticing this when we look straight at them.

In the case of incandescent lamps* we don't notice because the filament is just like a toaster coil, with warm up and cool down time.

This Product
is a single diode in a "button" form factor. How it "saves" lightbulbs is by only burning them for half the time. As shown in the above charts, AC voltage normally goes from zero to full voltage, then to zero, then goes back to full voltage. Half rectified voltage has a pause where the lamp cools for 1/60th (or 1/50th) of a second at zero voltage before burning again.

Quote:
 This is why I wanted to explain it after apollo mentioned the slightly higher lightbulb ratings that Edison produced, it is entirely logical that a slightly higher rated filament used in a lower voltage environment would result in a long lasting lightbulb.
On further research I'm thinking the OP light bulb is probably a 100w / 240v or 270v lamp installed in a 110v socket. "Back in the day" there were more variations available. 270v DC was used in some industrial applications. A savvy youngster working in a mine, ship or factory might snag a lightbulb for mom's pantry, knowing that 50w at 110v will last Mom forever.

Quote:
 When you think about it, it seems almost like a confidence trick - how could something so delicate such as a lightbulb, with a thin metal filament contained in thin glass bowl that has been vacuated and subjected to a seemigly violent reaction of high voltage producing heat and light possibly last a lifetime? Common sense dictates it must surely give up sometime, but apparently the tungsten filament does not agree, provided it is built slightly more sturdy than we actually build them or run at slightly lower voltage than they are rated for.
Light bulbs are, electrically speaking, just resistors. Mechanically, they're hair-thin bits of wire allowed to get really freaking hot. Edison's major task in "inventing" the light bulb (more a process of discovery than invention, as he knew what he wanted to achieve but had to figure out the parameters of success) was overcoming responses of the filament to heat. Most materials burn up or melt at the temperature of a light bulb filament, including tungsten. That's why light bulbs are either evacuated (have the air removed from inside) or have are filled with non chemically reactive gas (the "halogen" lamps have gas that won't react with the tungsten).

Quote:
 Finally, by rectifying the input voltage from 240 volts 50 Hz to 120 volts 25 Hz some people may notice a flicker in the bulb - some people won't as flicker is only detected by a human eye at below 24 Hz But to combat that, you can install a capacitor after the diode which will smooth out the waveform to be like D.C. and no flicker will be observable, also, the capacitor will help guard against the sudden surge when switching on and off.
As discussed above, rectifying voltage doesn't drop the voltage in half but does cut in half the time the filament is powered. The heating and cooling time of an incandescent lamp PLUS the persistence of vision effect "smooths" the change in voltage such that we don't notice it.

Using a capacitor smooths the voltage transition, because the capacitor charges and discharges at a rate governed by voltage and resistance.

Early film makers used film speeds of anything from 8 to 30+ frames per second, trying to get the persistence of vision to make smooth motion on screen while using as little film as possible. Cel animation (the stuff drawn by hand, built with layers -- for example any cartoon where faces stay still but the lips move for dialog) was done at 12fps (double framed for projection) but movies eventually standardized at 24fps. Older technology used 18fps, which is why some old films, even documentary stuff, may have the "Keystone Kops" look.

50 cycle voltage becomes 25 "blinks" per second when half-rectified, while 60 Hz voltage becomes 30/second. For reasons I don't understand US video runs at 29.97hz. It may be due to the time for CRT guns to reset from the bottom of the screen to the top. I've read that some digital video people like to edit at 25 frames per second because it's more mathematically ergonomic, and then fudge the difference up to 30fps (or not, for 50hz market) after the editing is done.

Quote:
 When I worked for another company, I spoke with the engineering supervisor about this subject (he was one of the team that invented Ceefax for the BBC and his name was listed on the first generation mobile phone network patents as technology he developed was used by the network),
Interesting reading up on . Never heard of it before you mentioned it.

Quote:
 he agreed with what I said and pointed out the much of the equipment we used which had buttons which were illuminated by bulbs when pressed, the bulbs rarely blew and this was because when the button was switched off, the equipment left a bit of DC current running through the bulb, but not enough to illuminate it. This kept the bulb 'warm' thus when you pressed the button and it illuminated the bulb to show the button was switched on, the bulb was not going from 'cold' to 'hot' it was going from 'warm' to 'hot' and as it was not such a violent change for the bulb, they didn't blow. Also, the equipment manufacturer built good power supplies into the equipment which prevented rippling of the power so the bulbs did not get to high a voltage and did not blow because of that condition.
This explanation makes sense. The dead-cold to hot transition creates the greatest mechanical stresses on a very small object. Also, the indicator lamps mentioned above don't run at the absolutely brightest color temperature possible. In other words, they're switched from "warm" to "hottish" rather than from "cold" to "Holy crap, that's hot!" Button illumination lamps don't need to run at full brightness to be effective, especially if the button is red.

Quote:
 So it seems the science is well understood by manufacturers and engineers and employed in 'professional' equipment where the customer demands higher reliability. But apparently, not many of us question why it can't be used elsewhere.
Um, actually there is a good reason. The "color temperature" of a lighting source affects our perception. Incandescent lights at rated voltage are pretty close to "ideal" " emissions, as is our sun. At lower voltage the lamp runs cool and gives "dim" light but at over-voltage will burn out quickly.

I have some "photography" lamps that are rated a very short number of hours. They produce a higher "" of light at the expense of burning out quickly. Shooting in color film they made a difference, but with digital camera I just adjust the white balance by shooting a sheet of paper and "drive on."

Quote:
 What annoys me, is the government and academics who advise government must be aware of these things and yet, while telling us we must be less wasteful they continue to allow manufacturer's to build and sell to us products that by design are wasteful. This situation then, is clear evidence of corruption and conspiracy in government, corporate and academic circles.
No. Government conspiracies are not required here.

Lifespan is only one of the variables for a product, and the least cost effective to engineer. Light bulbs were engineered around (in order of importance) cost to produce, product acceptability, ease of use (consumer convenience), and attractiveness. Seriously -- the A-envelope light bulb?

That's still the "standard" by which things are judged? Edison still drives the design standard of lighing fixtures?

Edison was a jerk with no artistic sensibility.

Sometimes I buy "flame" lamps just of sheer perversity.

Quote:
 I have known for a long time that this humble lightbulb mystery actually proves the conspiracy and surpressed technology case beyond all reasonable doubt. (I'm just waiting for the world to catch up!)
plus free market have given us the lightbulb as we now know it.

Breaking past these 2 factors has only begun. There's no "suppressed technolgy" involved, just market and industrial cost/benefit factors.

* Stagehand joke:
Q: How many stagehands does it take to change a light bulb?
A: It's not a lightbulb. It's a lamp.

Q: Okay, so how many stagehands does it take to change a lamp?
A: One. Unless you're using the scary ladder.

Last edited by apollo_gnomon; 30-12-2011 at 05:38 AM. Reason: OH CEE DEE!!

31-12-2011, 07:11 PM   #22
pi3141
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Quote:
 Originally Posted by apollo_gnomon Uh, no. Alternating current swings between + 120 (240) across 0v and down to - 120 (240).

Yes you are right, I simplified my explanation to illustrate the concept.

Allow me to correct myself.

Perform half wave rectification and reduce the mains voltage from 230V RMS AC or 650V peak to peak AC to 325V peak DC (Pulsating)

Average voltage of that waveform across a resistive load is given as Vav = Vpeak/Pi = 325/3.14 = 103Vav DC

(figures are simplified and there is barrier potential across the diode to consider)

I'm currently working nights for another 6 days, I will respond to your other points but it will take me a while.

Here is some random copy and pasting -

Quote:
 Now we come to the most popular application of the diode: rectification. Simply defined, rectification is the conversion of alternating current (AC) to direct current (DC). This involves a device that only allows one-way flow of electrons. As we have seen, this is exactly what a semiconductor diode does. The simplest kind of rectifier circuit is the half-wave rectifier. It only allows one half of an AC waveform to pass through to the load. (Figure below) For most power applications, half-wave rectification is insufficient for the task. The harmonic content of the rectifier's output waveform is very large and consequently difficult to filter. Furthermore, the AC power source only supplies power to the load one half every full cycle, meaning that half of its capacity is unused. Half-wave rectification is, however, a very simple way to reduce power to a resistive load. Some two-position lamp dimmer switches apply full AC power to the lamp filament for “full” brightness and then half-wave rectify it for a lesser light output. In the “Dim” switch position, the incandescent lamp receives approximately one-half the power it would normally receive operating on full-wave AC. Because the half-wave rectified power pulses far more rapidly than the filament has time to heat up and cool down, the lamp does not blink. Instead, its filament merely operates at a lesser temperature than normal, providing less light output. This principle of “pulsing” power rapidly to a slow-responding load device to control the electrical power sent to it is common in the world of industrial electronics. Since the controlling device (the diode, in this case) is either fully conducting or fully nonconducting at any given time, it dissipates little heat energy while controlling load power, making this method of power control very energy-efficient. This circuit is perhaps the crudest possible method of pulsing power to a load, but it suffices as a proof-of-concept application. Link - http://www.allaboutcircuits.com/vol_3/chpt_3/4.html

Here is a quote from Wiki

Quote:
 Preheat Some types of incandescent (filament) lamps should not be switched to full power from cold, and doing so can shorten their life dramatically owing to the large inrush current that occurs. To soften the blow to the lamps slightly, dimmers may have a preheat function. This sets a minimum level, usually between 5% and 10%, which appears turned-off to the audience, but stops the lamp from cooling down too much. This also speeds up the lamp's reaction to sudden bursts of power that operators of rock'n'roll-style shows appreciate. The opposite of this function is sometimes called top-set. This limits the maximum power supplied to a lamp, which can also extend its life. Link - http://en.wikipedia.org/wiki/Dimmer

Here is a manufacturer that mentions preheating.

Quote:
 The range of Pulsar Rackpaks encompasses equipment suitable for the smallest venue up to the largest..... Dimming versions feature lamp Preheat switch to extend lamp life Link - http://www.pulsarlight.com/Products/...2/Default.aspx

02-01-2012, 05:47 AM   #23
pi3141
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Quote:
 Originally Posted by apollo_gnomon This Product is a single diode in a "button" form factor. How it "saves" lightbulbs is by only burning them for half the time. As shown in the above charts, AC voltage normally goes from zero to full voltage, then to zero, then goes back to full voltage. Half rectified voltage has a pause where the lamp cools for 1/60th (or 1/50th) of a second at zero voltage before burning again.
How interesting, a product to market using the exact idea we put forward in our project. I was interested to know more about this product, when it came to market etc and did a quick search. Turns out it was developed by NASA for the Apollo program which put a smile on my face!

Well we did this project in 1999 but Wiki lists the Apollo program as 1968 to 1972 so they beat us by many years. Oh well nothing new under the sun.

The article does also confirm that most bulbs blow when going from cold to hot state at switch on.

06-01-2012, 01:30 AM   #24
leon11
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Quote:
 Originally Posted by huyi Is it true about manufactures today, they intentionally make the product last a couple of years so you buy another one, nothing today is built to last compared to a decade ago. (or longer)
ofcourse! craftsmanship has steadily gone downhill and the market is now full of sharks who sell substandard products at an increased price. In almost every sector!

Isnt the first ever lightbulb still on...?!

06-01-2012, 07:58 PM   #25
reiko noir
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Quote:
 Originally Posted by thecatsmeow The couch you speak of is probably a chaise longue
Yes, that was what it looked like.

Thank you.

I couldn't remember the exact name for those types of chairs.

20-01-2012, 04:23 AM   #26
apollo_gnomon
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Quote:
 Originally Posted by leon11 ofcourse! craftsmanship has steadily gone downhill and the market is now full of sharks who sell substandard products at an increased price. In almost every sector! Isnt the first ever lightbulb still on...?!
Not the 1st lightbulb ever, but a very old bulb is still burning

http://www.snopes.com/science/lightbulb.asp

It's a 4 watt carbon-filament, nick named the "Centennial Light bulb."

Bulbcam, so you can check on it yourself, to make sure it's still lit!
http://www.centennialbulb.org/cam.htm

Last edited by apollo_gnomon; 20-01-2012 at 04:24 AM. Reason: fix bulbcam link

 20-01-2012, 04:45 AM #27 the obliterati Senior Member   Join Date: Dec 2007 Location: west coast of the land of 666 Posts: 232 Likes: 0 (0 Posts) Article about the centennial light. Reputable news source too lol. http://www.dailymail.co.uk/news/arti...lightbulb.html
23-01-2012, 07:41 PM   #28
pi3141
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Quote:
 Originally Posted by apollo_gnomon As I mentioned up-thread, the end-of-lifecycle cause of failure in incandescent lamps is evaporation of the filament. When the glass envelope gets dark, that's filament metal condensing on the glass. Halogen lamps have gas that prevents the evaporated metal from condensing on the glass, so instead it condenses back on the filament. In that case, the filament gets progressively more brittle as more and more metal is in a crystalline structure rather than unstructured (and more flexible) drawn wire.
Quite true, our project was based on the assumptions that 'most' lightbulbs blow either when being switched on due to the shock or when in operation and they are pushed over their rated voltage by mains fluctuation. The idea was to extend the life of the bulb by countering at least one of those causes.

The basic conclusion as I described was that by halving the input power, you would run the lightbulb well within tolerances and extend its life.

Quote:
 Originally Posted by apollo_gnomon Positive vs. negative voltage is irrelevant to resistive loads.
I'll come back to that, maybe a very relevant point in this discussion.

Quote:
 Originally Posted by apollo_gnomon This statement is approximately correct, but not for the reason you think. With one diode you get half-wave rectified voltage. I don't know if LED Christmas lights are infesting your area the way they are here, but if they are you might have noticed they tend to strobe when you see them out of the corner of your eye or as you drive past, but not when you look at them straight. That's because those strings of lights are driven by ac passed through one diode. The Persistence of Vision effect keeps us from noticing this when we look straight at them. In the case of incandescent lamps* we don't notice because the filament is just like a toaster coil, with warm up and cool down time. This Product is a single diode in a "button" form factor. How it "saves" lightbulbs is by only burning them for half the time. As shown in the above charts, AC voltage normally goes from zero to full voltage, then to zero, then goes back to full voltage. Half rectified voltage has a pause where the lamp cools for 1/60th (or 1/50th) of a second at zero voltage before burning again.
I didn't know they were using the technology, either in Nasa related projects or modern christmas tree lights!

Quote:
 Originally Posted by apollo_gnomon Light bulbs are, electrically speaking, just resistors. Mechanically, they're hair-thin bits of wire allowed to get really freaking hot. Edison's major task in "inventing" the light bulb (more a process of discovery than invention, as he knew what he wanted to achieve but had to figure out the parameters of success) was overcoming responses of the filament to heat. Most materials burn up or melt at the temperature of a light bulb filament, including tungsten. That's why light bulbs are either evacuated (have the air removed from inside) or have are filled with non chemically reactive gas (the "halogen" lamps have gas that won't react with the tungsten).
To respond to your point about filament vapour condensing is the lightbulb wearing out during the natural course of its life. By making the filament thicker, it would obviously take longer to wear out. This is analagous to reducing the input power, the filament would be stronger than it needed to be and would logically take longer to wear out. The strategies I have suggested work to prevent premature breakage of the lightbulb and allow the longest time for the filament to naturally wear out which should be at a slowed rate due to the reduced input.

I suppose if the bulb is rated at 240v, we both know that the voltage swing would actually be higher than that, but the peak voltage on either swing would always be 240V (rms a.c. ) So in fact, our half wave explanation may not prevent blowing due to ripple currents as the bulb would still see a 240V peak + extra ripple voltage when it occurs.

Quote:
 Originally Posted by apollo_gnomon As discussed above, rectifying voltage doesn't drop the voltage in half but does cut in half the time the filament is powered. The heating and cooling time of an incandescent lamp PLUS the persistence of vision effect "smooths" the change in voltage such that we don't notice it. Using a capacitor smooths the voltage transition, because the capacitor charges and discharges at a rate governed by voltage and resistance.
Yes. You see this was our recommendation. Use a capacitor to smooth out the voltage, hence there would be no 'off' period for the lightbulb to cool, hence in our opinion, the extended life was explained by reduced input power and not burning the bulb for half the time. I'll pick this idea up again below.

However, a rising and falling DC signal below half power of the lighbulbs rating sounds like an interesting avenue of thought. Crude capacitor smoothing not completely ironing out the peaks cooling the filament compared to a constant DC.

Quote:
 Originally Posted by apollo_gnomon Early film makers used film speeds of anything from 8 to 30+ frames per second, trying to get the persistence of vision to make smooth motion on screen while using as little film as possible. Cel animation (the stuff drawn by hand, built with layers -- for example any cartoon where faces stay still but the lips move for dialog) was done at 12fps (double framed for projection) but movies eventually standardized at 24fps. Older technology used 18fps, which is why some old films, even documentary stuff, may have the "Keystone Kops" look. 50 cycle voltage becomes 25 "blinks" per second when half-rectified, while 60 Hz voltage becomes 30/second. For reasons I don't understand US video runs at 29.97hz. It may be due to the time for CRT guns to reset from the bottom of the screen to the top. I've read that some digital video people like to edit at 25 frames per second because it's more mathematically ergonomic, and then fudge the difference up to 30fps (or not, for 50hz market) after the editing is done.
Well, I'm a broadcast engineer, my training taught me the U.K selected 50Hz TV's for two reasons, firstly it was beyond the flicker effect threshold of 24 frames per second used in film and secondly, it just happened to be at mains frequency which allowed the TV's to have cheaper timing circuitry.

From what I have read, persistence of vision is a subjective topic. But in the TV realm, 25Hz is considered just beyond the threshold although some people do detect higher.

The line scans frequency were selected (from memory) so as not to cause interference with the luminance signal and retain backwards compatability with Black and White TV sets.

Quote:
 Originally Posted by apollo_gnomon Interesting reading up on Ceefax. Never heard of it before you mentioned it.
Apparently some of the data encoding techniques developed for Ceefax were implemented on the first gen mobile phone networks and thats why the engineer got his name on the patents.

Quote:
 Originally Posted by apollo_gnomon Um, actually there is a good reason. The "color temperature" of a lighting source affects our perception. Incandescent lights at rated voltage are pretty close to "ideal" black body" emissions, as is our sun. At lower voltage the lamp runs cool and gives "dim" light but at over-voltage will burn out quickly.
Yes, but plenty of people are happy with dimmed lighting and again, there's no reason why the manufacturers can't adjust the properties of the filament for a good compromise of color temperature and lamp longevity.

Quote:
 Originally Posted by apollo_gnomon No. Government conspiracies are not required here. Lifespan is only one of the variables for a product, and the least cost effective to engineer. Light bulbs were engineered around (in order of importance) cost to produce, product acceptability, ease of use (consumer convenience), and attractiveness. Seriously -- the A-envelope light bulb?
Well government conspiracies may be a bit strong but then again, the government has long known about planned obsolescence, so to say they are ignorant of manufacturers intentionally making products with a reduced life cycle is unlikely. Its been shown not only in the recent lightbulb conspiracy - pyramid of power documentary but also by journalists reporting on these lightbulbs that designs for long lasting lightbulbs have existed for decades and they have been kept from the market for financial reasons.

It may seem like a small point but when you consider that many more items may also have been kept from the market place and the amount of waste our society produces and the environmental damage it causes, I personally feel it becomes criminal to allow the situation to continue and if the government or its advisers are at some level aware of this then yes, I say it is a criminal conspiracy of silence between academics, government and manufacturers to sell us inferior products for profit regardless of the damage they are causing and the resources they are depleting.

The end result is the manufacturer's have kept better products off the markets for profit and the government has to some extent allowed them to do so.

Quote:
 Originally Posted by apollo_gnomon * Stagehand joke: Q: How many stagehands does it take to change a light bulb? A: It's not a lightbulb. It's a lamp. Q: Okay, so how many stagehands does it take to change a lamp? A: One. Unless you're using the scary ladder.

Lol.

(sorry it to so long to respond, been a bit busy and had an ongoing problem at work - are you any good with Virtual Networks? )

24-01-2012, 05:42 AM   #29
apollo_gnomon
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Quote:
 (sorry it to so long to respond, been a bit busy and had an ongoing problem at work - are you any good with Virtual Networks? )
I'd rather have one post like the one above once a month than all the posts I've read while waiting for your in-depth response. I'll comment on it later when I have more time and am sober.

And no, sorry, I'm not versed in Virtual Networks. I was well versed in the state-of-the-art of computing when DOS 3.3 and a '386 were the 'thing'. I built my own hard drive out of surplus parts. Then I got into graphic arts, and then carpentry. Now I'm just a "user."

 24-01-2012, 05:52 PM #30 thecatsmeow Banned   Join Date: Dec 2011 Location: In limbo Posts: 5,622 Likes: 3 (3 Posts) I found this which appears to be much easier to follow than anything else I've found (being a total beginner) what do our "experts" think? http://hilaroad.com/camp/projects.html Which inverter is the best one on this website for the solar panel that I bought? Alternatively am I better off with batteries? Edit:Article here with energy saving lightbulbs containing mercury Last edited by thecatsmeow; 24-01-2012 at 06:10 PM.
25-01-2012, 05:20 AM   #31
apollo_gnomon
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The HILA projects are okay, but not great. I will point out that the recommended book on the Electronics Introduction is the same book I recommend upthread.

Quote:
 Which inverter is the best one on this website for the solar panel that I bought? Alternatively am I better off with batteries?
You can't run an inverter off a solar panel. Well, you could if you have enough panel and the sun is shining brightly, but in practice you wouldn't do it that way. You run the inverter off the battery, and recharge the battery with the solar panel between uses. The battery system can supply huge amounts of power at once, at much greater rates and reliability than the solar panels alone.

Also, you need to have a charge controller between the solar panel and the battery to protect the battery. Overcharging and undercharging batteries can lead to battery failure, sometimes disastrous and always expensive.

Watts = volts x amps. The 145w 12vdc solar panel in your link is going to put out about 10 amps in full sun. Take a look at the plate labels for the devices you want to run with this. A drill might pull 4 amps, but a circular saw will pull 12 to 15 amps. Those are both "inductive" loads, meaning they use electromagnets. Those pull huge amounts of power on startup and then less as the motor turns. "Resistive" loads like a toaster or lightbulb don't. Well, lightbulbs can be tricky because the resistance of the filament changes as it heats but we'll ignore that and move on. The point is that motors have huge spikes of load on startup but lights and toasters don't.

Batteries are rated in "amp-hours" meaning the number of hours that the battery will supply 1 amp. Most batteries will give more amp/hours (also written Ah) if discharged at lower rates than if discharged at higher rates. So a 100 Ah battery will theoretically supply a 10 amp load for 10 hours, but in practice some batteries will do this better than others. Then the battery will need to be recharged by the solar panel and any other charger you have connected (wall voltage, generator, vehicle) to put those amp/hours back into the chemistry. The rate at which the battery is charged is called C, for capacity. If the 100Ah battery is recharged at 10A, that's a C/10 (capacity divided by 10) charge rate. Some batteries can be charged at 1C but most can't. Trickle charge mode runs at C/500 for some designs, just enough to keep the electrons in the battery from getting out. Things like emergency EXIT signs with lights often have this kind of charger.

There are losses every step of the way, so you don't get out what you put in to anything -- the battery, the inverter, the charge controller, everything. Designing a solar system means counting up your loads and figuring out how to feed the batteries after you use them and adding in all the losses. So you have to "overbuild" your system some amount just to get it to work.

Last edited by apollo_gnomon; 25-01-2012 at 05:33 AM.

 25-01-2012, 07:20 AM #32 thecatsmeow Banned   Join Date: Dec 2011 Location: In limbo Posts: 5,622 Likes: 3 (3 Posts) @ Apollo Gnomon Thank you so much you've been very, very helpful.
30-01-2012, 07:50 PM   #33
pi3141
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Quote:
 Originally Posted by thecatsmeow Which inverter is the best one on this website for the solar panel that I bought? Alternatively am I better off with batteries?
Hiya!

Sorry for the delay responding.

Haven't been through that educational website but it looks ok.

Where do we start!

First of all, you have to weigh up what your trying to achieve. Now I think I know what that is, energy independance. If you want to do this on your own terms then you have to realise your breaking new ground, certainly when it comes to some of these solar companies, what your trying to do will not be the normal for them. If they're any good, you'll get advice nd help, otherwise you'll no doubt get blank stares and silent telephone conversations! Also, until you try, you don't know how successful this will be. You could spend fortunes, then I'm sure you will manage it ok, but doing it on a budget, as you go along for instance, will mean a different approach.

I don't know much about your circumstances, rich poor, renting home owner etc. However, one thing is for sure, no matter what you do, you will need a qualified electrical installer to fit it for you. Certainly any connections to the fuse box etc should be done by an electrician. If your squatting on a farm then you can do what you like. :-)

Now, you have a panel, capable of generating some energy. My guess is you want the solar panel to charge a battery pack to then power your home. 1 panel may do it if you use a wood burning fire, gas oven and have limited electrical requirement - i.e. you lead a simple life, put a jumper on rather than turn up an electric fire etc.

I did a quick search and found a UK webpage from a guy who was setting up his house to run off a portable generator. He made his own connection and showed how it 'could' be done and he also explained how to do it 'to code' He suggests a change over switch to fully isolate the mains from the generator (your batteries) A switch, with proper installation is exactly what is required.

Quote:
 George Maats Generator Connect faq Link - http://www.anetstation.com/survival01.htm
Most solar panel companies will be trying to sell you an adaptor (for want of a better word) to feed your energy directly back to the UK mains system and get the equivalent offset from your bill, thus reducing it. Hence, you may not get much help from them. That is the way most people are doing it and hence the norm here i the UK.

This method, feeds your energy back into the grid, offset's it against your bill and saves you money. Any installation you make such, as the inverter to feed into the grid and the associated wiring, can then stay with the property should you leave and be used as a selling point. You could take your panel with you unless its permanently installed on the roof as opposed to being on a frame in your back yard etc

Should you choose to live off your own power then firstly, you'll want a changeover and isolation switch. This will let you get back on the grid if you need to but keep you off the grid in a safe way. They call these switches transfer switches, they have other names I came across but I can't find it now. Contract a qualified electrician to supply and fit the switch, then your legally covered and the installation will be safe. Like I said, you will have to accept the fact that if you leave the property you will leave the switch, but we're not talking thousands, its just a switch and haf a day or so to install it.

You will need to work out how much energy your panel is likely to generate and get enough batteries to store it, that shouldn't be too hard, in fact the solar panel company should easily supply that figure.

Then you will need the inverter to connect the batteries to the fuse box not the solar panel to the mains.

I didn't see any inverters on that website that are designed for that specific purpose. The good news is, inverters designed for that purpose should be cheaper.

There's a lot more you could consider, but lets keep this focussed for the time being.

Have a read of this article, it looks like a brilliant overview, of similar but not exactly what i think you are trying to achieve.

Quote:
 Building a Solar Power Mains Backup System for Your Home Link - http://www.thebiggreenidea.org/news/...-backup-system
The inverter he uses there is unlikely to be what you want, unless of course, you have simple electrical requirements, a laptop, mobile phone charger and a few LED houehold lightbulbs for instance. Cooking and heating achieved by gas or other means.

Hope this post has been of help to you. I'm sure you will have more questions so just ask and I'll answer back as soon as I can. You could start a thread, you would get lots of help and idea's and it could turn into a very useful 'How To' for others with lots of information and links to informative articles and sites etc.

30-01-2012, 08:26 PM   #34
pi3141
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Quote:
 Originally Posted by thecatsmeow Thank you so much you've been very, very helpful.
Apollo has given some excellent advice there.

Try and figure out how much your panel is likely to generate in a typical day (I'll have a look for you and try and give you a figure) Then basically, you look at how many batteries you will need to store all that energy. 12V car batteries store between 100 & 200 aH - amp hours, that means, a 200 aH battery will supply 1 amp for 200 hours or 200 amps for 1 hour. They are 12V so their power (basically) is Voltage x Amps 12V x 200 = 2400 watt hours or 2.4 Kw/hours

So if you know how much energy your panel will produce on a typical day - say 10 amps per hour for 12 hours = 120 amp hours (aH), or 12volts x 10amps x 12 hours = 1440 watt hours, then a single 12V, 220aH, 'deep cycle' battery will more than suffice.

You could probably use this through a simple connection to your fusebox to power a single isolated household circuit, fridge and freezer for instance.

 30-01-2012, 08:42 PM #35 pi3141 Senior Member   Join Date: Jul 2009 Posts: 3,547 Likes: 100 (79 Posts) In fact, the more I think of it, having a single solar panel, recharging a battery, to run your fridge and freezer through a simple, dedicated, isolated circuit, meaning your fridge and freezer always works regardless of power cuts and you get a reduced electricity bill because your household draws less power is an excellent idea!! You could also wire a spare single mains socket so that in the event of a power cut, you have also have a working electrical mains outlet. You would not need an expensive inverter to do this nor a transfer switch.
30-01-2012, 08:45 PM   #36
thecatsmeow
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Quote:
Thank you...I'm glad I didn't buy the inverter now just some batteries. I will get an electrician too. Thanks for all the good advice

30-01-2012, 09:33 PM   #37
pi3141
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Quote:
 Originally Posted by thecatsmeow Thank you...I'm glad I didn't buy the inverter now just some batteries. I will get an electrician too. Thanks for all the good advice
Your welcome. I hope it is useful for you.

If you want to connect a few low power devices to your system, you could increase your battery capacity such that during summer months it gets charged fully so that during winter months there is enough power to maintain essentials like fridge and freezer. That may be a cheap but efficient use of such a system which also achieves a degree of energy independence.

31-01-2012, 09:34 PM   #38
pi3141
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Lets nail this down.

Take a solar panel, buy a collector, charger, inverter combi unit, connect it to your fuse box on an isolated ring, connect your fridge, freezer, some lamps and a couple of sockets/outlets. Put diodes in the lamp wiring - its your ring, do what the hell you want with it!

Then you maintain power and food supplies during power cuts, have light from long lasting lamps and access to a power source for radio or mobile charging during power outages.

While you have power, you save money on your bill.

The linked article - Building a Solar Power Mains Backup System for Your Home, uses a Powermaster PM-1500SL 24V, for a single panel installation you could use the cheaper PM-1500SL at £900. But that charges at a level 5 times higher than a single panel installation would need.

Quote:
 POWER MASTER COMBI SL Link - http://www.wirefreedirect.com/powerm..._inverters.asp
If you just run low power appliances continously through a low power inverter and have a couple of sockets wired to give emergency access to power, a 150 Watt inverter would be ok.

The panel supply's 10 amps (?), the battery capacity is say 220aH or 11 amps for 20 hours. I don't know now while writing what a single panel will supply, a single panel will potentially supply 10 amps while charging during the day for half a 24 hour period. But it will not supply 10 amps per hour for the whole day, all year round. So a continous current of 5 amps for 24 hours is about right. Thats got to be fridge freezer territory.

Quote:
 GENIUS INVERTERS GP 12-150 £40 Link - http://www.wirefreedirect.com/genius_inverters.asp
You'll need a solar regulator.

Quote:
 Fox Solar Regulators Fox 250 £130 Link - http://www.wirefreedirect.com/fox_solar_controllers.asp
At a guess, powering your fridge freezer, you could save £10 a month.

Keep the battery indoors next to the fusebox out of the elements.

The figures are 'top of the head' and so is the how to, with examples taken from the first source I found.

Seems plausible and a good idea though.

 31-01-2012, 09:55 PM #39 pi3141 Senior Member   Join Date: Jul 2009 Posts: 3,547 Likes: 100 (79 Posts) Oops, Battery £220 Quote:
 01-02-2012, 03:37 AM #40 apollo_gnomon Banned   Join Date: May 2010 Posts: 6,392 Likes: 6 (4 Posts) Here's a site with a table of common appliances and how much power they use: http://www.donrowe.com/inverters/usage_chart.html There's a type of building called an Earthship that is designed to be fully self contained with regard to water and power. I suggest looking into them, as the builders have figured out many things over the years that could be incorporated into ordinary homes.

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