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Modified sinewave to pretty good sinewave?

Bluejets

Oct 5, 2014
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Proof of the pudding as they say, is usually in the eating.
Now include inefficiency.

BTW...don't forget the inevitable run down in cell characteristics.....
 

HANKMARS

Jul 28, 2019
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1hp is 736W and can lift 75kg 1 metre in 1 second (wikipedia).

Using maff - 1000kg would be raised 1 metre in 13.3 seconds (1000/75) using 736W and take 40 seconds to reach 3 metres.

A typical alkaline AA battery has a capacity of 3.9Whr so three of them would have 11.7Whr. Divide the 736W by 11.7 you get 63 and multiply by the 40 seconds = 2516 seconds or about 42 minutes to take 1 tonne 3 meters vertically.

Notably the 42 minutes is within the 1 hour rating of the batteries and, as ever, this all assumes 100% efficiency in all moving parts AND the required torque/gear reduction system (loss-less).

Clearly the 100% efficiency (or loss-less) aspect is the killer and makes the difference between believable and 'impossible' - but, in THEORY, yes you can use 3 AA batteries to lift 1 tonne 3 metres.

Give this 'truth' your raised weight can only return the same energy when it falls (less given the system losses in falling) so the maff holds up as does the impracticality of it all.
Let's assume we loose 99% of energy in mechanical/electrical losses. That would mean a machine powered by 3 AA cells can raise 1 tonne 3 centimeters. I can visualize that. I believe in your last calc, you need to take 11.7 into another WH value, not just a watt value. I could be mistaken. It gets confusing after a while.
 

HANKMARS

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I am still quite skeptical of these results. Wiki is after all contributions not text book necessarily.
 

HANKMARS

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Damn that maff eh? :D
I inadvertently involved horse power, a unit that I intentionally try to avoid. Disregarding losses due to friction, etc., how many kWH are required to lift a 1 tonne mass 3 meters? Do no involve horse power in the formula.
Damn that maff eh
1hp is 736W and can lift 75kg 1 metre in 1 second (wikipedia).

Using maff - 1000kg would be raised 1 metre in 13.3 seconds (1000/75) using 736W and take 40 seconds to reach 3 metres.

A typical alkaline AA battery has a capacity of 3.9Whr so three of them would have 11.7Whr. Divide the 736W by 11.7 you get 63 and multiply by the 40 seconds = 2516 seconds or about 42 minutes to take 1 tonne 3 meters vertically.

Notably the 42 minutes is within the 1 hour rating of the batteries and, as ever, this all assumes 100% efficiency in all moving parts AND the required torque/gear reduction system (loss-less).

Clearly the 100% efficiency (or loss-less) aspect is the killer and makes the difference between believable and 'impossible' - but, in THEORY, yes you can use 3 AA batteries to lift 1 tonne 3 metres.

Give this 'truth' your raised weight can only return the same energy when it falls (less given the system losses in falling) so the maff holds up as does the impracticality of it all.
Consi der

You never get more out than you put in so using a motor to lift something that drops to generate power is a pointless waste of time/resource although it's neither my time nor my resources so fill your boots!

The best situation for off grid would be anywhere you can utilise water flow - hydro (micro hydro in particular) - but obviously solar PV works for some and so does wind.

I've arranged my own home to be capable of running on 300W of electricity (max 500W) and that covers essential lighting, comms (internet) and entertainment (TV/lapdog). This is currently via the aforementioned inverter-generator that runs for 8+ hours at a 500W load on a 5 litre tank of petrol. We otherwise have a woodstove (I live in a forest) for all heating, a fresh water loch (with fish), private water and sewage facilities, hunting (if necessary), local farmers with livestock and facilities for growing food.

Personally I'd use solar except for the distinct lack of sunlight in Scotland! Oh, we get some, but not reliably and it certainly wouldn't pay for itself in its lifetime but when it's a case of some electricity or no electricity your options are decided for you!

There are many, many people I know looking for a lifestyle like mine (or yours) and we get loads of enquiries from customers asking if there are any properties for sale - short answer, no. Given the current situation I have no intention of letting what we've developed and created go to waste.
Consider this. U ( change in potential energy ) = m (mass) x g ( gravitational force = 9.8 ) x h ( 3 meters ). U = mgh. U = 1000 kg x 9.8 x 3 = 29,400 kj = 29,400,000 joules. 1 joule = 1 Ws. 29,400,000/3,600,000 ( conversion Ws to kWH ) = 8.7 kWH. The attachment is a photo of a typical cloudy sunrise in the Arizona desert.
 

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HANKMARS

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All that does, assuming the correct type of capacitor, will be to slightly change the power factor.
AC does not follow any DC specs.
What type of correct capacitor do you recommend? I am foreseeing a metal can, 2 screw lug terminals on the end, about the size of a pint milk container. Kinda like the one I changed out on the Inductively Coupled Plasma Emission Spectrograph. ICPES ( IC for short ). Came with its own shorting wand. Attached to the back panel with a couple garden rake spring clips. About 20" long, composite handle. Lest we forget all acquired knowledge and glimpse the energy within the blue lighted one. The power factor is the value of transmitted energy related to available power? If that is close to truth, then I can maybe use it. The modi-sinwav delivers a hefty power factor (pf) with its peak V output at square wave time periods. My thots were that the caps would dull, or round off the sharp edges, making the waveform nearer sinusoidal, or roundish, lowering the pf, resulting in cooler running windings.
 
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Bluejets

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Your problem is you apparently look up Google for a few technical terms and then redistribute them in your answers here without any understanding of what is the theory behind the process.
 

HANKMARS

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Your problem is you apparently look up Google for a few technical terms and then redistribute them in your answers here without any understanding of what is the theory behind the process.
That is not close to my problem. Can you put your last reply into some sort of logical terms and references? Are in the correct forum. Nevermind.
 
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HANKMARS

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Your problem is you apparently look up Google for a few technical terms and then redistribute them in your answers here without any understanding of what is the theory behind the process.
If I did not mention it prior, the caps would be in parallel, maybe I said series confusing the subject. In series it would create a phase shift of 120 degrees indeed changing the pf. Better?
 

HANKMARS

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Your problem is you apparently look up Google for a few technical terms and then redistribute them in your answers here without any understanding of what is the theory behind the process.
The short abbreviation for the emission spectrograph is ICP. Maybe that will help. It has been over 20 years since I worked on one so I do sometimes misplace a letter or two. Anyway, I'm am still interested to hear ideas as how to simply and inexpensively convert a high power square wave into a sinewane.
 

kellys_eye

Jun 25, 2010
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Anyway, I'm am still interested to hear ideas as how to simply and inexpensively convert a high power square wave into a sinewane.
Short answer - there isn't one. If there was then all modified squarewave 'sine' inverters would be sold as 'pure sine'. Give it up....
 

HANKMARS

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Short answer - there isn't one. If there was then all modified squarewave 'sine' inverters would be sold as 'pure sine'. Give it up....
Sure. After all, "That's how we've always done it." Thanks for the encouragement. Legend has it, Isaac Newton was a SOB. part-time judge. Kinda of an A-whole from the bench. Stern, ever-serious. The only recollection of him seen laughing comes from a instance when he presented his pimer to geometry to the king who remarked, " Who would ever have any use for this?"
 

HANKMARS

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Well, gunna try it anyway. Gunna lash up my bogus "modi-sinwav" to a couple power FETs whose gates are driven by the generic high freq triangle wave hetrodyned with a modulated PWM and load it and see what it looks like. Ten bucks worth of parts a a couple hours labor. I'll get back to ya.
 

HANKMARS

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Oh, BTW, when you come across any inverter that has "pure sinewave" printed on it, that is more of a classification of category, not a guarantee of pure-sinewave output. Quality varies greatly dependent upon manufacturer.
 

kellys_eye

Jun 25, 2010
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Well, gunna try it anyway. Gunna lash up my bogus "modi-sinwav" to a couple power FETs whose gates are driven by the generic high freq triangle wave hetrodyned with a modulated PWM and load it and see what it looks like. Ten bucks worth of parts a a couple hours labor. I'll get back to ya.
I don't doubt your determination but in a world where cost/benefit/profit is a priority, no one has 'cracked' what you're trying to do therefore no one will. That is CAN be done is arguable - that it should be or can be done effectively/efficiently is already decided.

But it's your time, your money.

PS - I'm fully aware of the 'sine' issue re products and make no definitive statement or recommendation for any specific item. Caveat Emptor.
 

HANKMARS

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I don't doubt your determination but in a world where cost/benefit/profit is a priority, no one has 'cracked' what you're trying to do therefore no one will. That is CAN be done is arguable - that it should be or can be done effectively/efficiently is already decided.

But it's your time, your money.

PS - I'm fully aware of the 'sine' issue re products and make no definitive statement or recommendation for any specific item. Caveat Emptor.
If an acceptable functioning design were to be produced free of charge (that would be my time spent) I suspect the cost/benefit/profit bottleneck will be component cost and manufacturing cost. We can nix the manufacturing cost. In a world where one can purchase a 55 gallon drum of new, unpackaged electronics components for 100-200 dollars, component costs are no longer an issue. "How can that be?" you may ask. It happens when intelligent, ambitious, entrepreneurial types, with good credit or bucu personal wealth, jump into the manufacturing business in a leap of faith and have eyes glazed over with dreams of untold riches. Happens every day. Due to unforeseen costs or predictable costs that were overlooked by an over zealous wannabe. The company fails, the bank forecloses, and thousands of dollars worth of stock and equipment are forfeited to the bank and have to be removed from a facility so that it can be sold to the next dreamer. The bank really has no interest in the value of said stock and equipment because its value is petty cash in their realm of business. The bank may likely hire an auction company to pack up said junk and cart it away. Considering that I reside in a country whose regime is currently putting a death grip on small independently owned businesses, this scenario will be played out thousands of times in the coming years. But alas, I do not even possess the wealth to be a buyer at these auctions so I resort to another untapped supply house which comes in the form of salvage. Actual, the term salvage is applied to a failed business' stock but it is much prettier and brings better prices. With a glut of products of inferior design and manufacturing standards, e.g. Made in China, a flood of broken, failed products hit the trash heap like a storm surge hits Florida. I'm retired, electronics work is a labor of love, so yeah, I get over the top now and then but it is interesting what one discovers on impossible pursuits.
 

Harald Kapp

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A capacitor alone will not help smoothing the "pseudo sine" to a sine wave. Look at this simulation:
1664716498325.png
V1 (top trace, green) is the "pseudo sine source (output of the inverter). Source V2, V3 and V4 are exact copies to replicate that output.
v2 (lower case, 2nd trace from top, blue) is the voltage "filtered" by a 10 nF capacitor. There is no difference to v1, as the only effect of the capacitor is that it will draw more current from V2 to get charged and discharged.
v3 (lower case, 3rd trace from top, red) uses an additional 10 Ohm resistor to create a low pass filter, but due to the low component values also without any visible effect.
v4 (lowest trace, light blue) uses a 100 Ohm resistor and a 10 µF capacitor to increase the filtering effect, but the result is still miles away from a sinusoidal waveform.
R3 and much more R4 will dissipate lots of power (depending on the load current) and will drop quite some voltage, so the output (v3 or v4) can't reach the full swing.
Even increasing the capacitor to 100 µF still makes the waveform not very sinusoidal:
1664717048615.png

Imho the hints you have been given previously are sound: If what you want to achieve could be done as easily as you think, it would have been done. Obviously it can't be dome in such an easy way.
 

HANKMARS

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A capacitor alone will not help smoothing the "pseudo sine" to a sine wave. Look at this simulation:
View attachment 56420
V1 (top trace, green) is the "pseudo sine source (output of the inverter). Source V2, V3 and V4 are exact copies to replicate that output.
v2 (lower case, 2nd trace from top, blue) is the voltage "filtered" by a 10 nF capacitor. There is no difference to v1, as the only effect of the capacitor is that it will draw more current from V2 to get charged and discharged.
v3 (lower case, 3rd trace from top, red) uses an additional 10 Ohm resistor to create a low pass filter, but due to the low component values also without any visible effect.
v4 (lowest trace, light blue) uses a 100 Ohm resistor and a 10 µF capacitor to increase the filtering effect, but the result is still miles away from a sinusoidal waveform.
R3 and much more R4 will dissipate lots of power (depending on the load current) and will drop quite some voltage, so the output (v3 or v4) can't reach the full swing.
Even increasing the capacitor to 100 µF still makes the waveform not very sinusoidal:
View attachment 56421

Imho the hints you have been given previously are sound: If what you want to achieve could be done as easily as you think, it would have been done. Obviously it can't be dome in such an easy way.
Very nicely done simulation. Mind if I ask what program/app/simulator you did this with? Quite honestly, while pondering the notion of producing a sinewave from the choppy waveform, the caps were my first flash of thot. Keep in mind I will be using high voltage, 110 V at let's say 800 W. The invertor I am working with will power an 1100 W microwave oven and a 1000 W toaster oven. Not simultaneously of course. The toaster oven will be fine I'm sure but I am concerned that the long duration of peak voltage will burn transformer windings. Do you consider that a valid concern? I'm relatively new to inverter use and am going by stories of burned motors and other equipment, hence my theory of long duration of full voltage. It has been a while since I saw the inverter output on the scope. I will guess that the modi-sinwav does not have the same Vp value as a traditional house current since I also assume inverter design is seeking and RMS voltage of 110-120 V. 110 x 1.414 =~ 155 Vp x 2 = 310 Vpp. So as my design of a modification is developing, it appears that the existing inverter may become no more than a power supply. The PWM drive of a FET gate (or its drive) seems quite adaptable. The existing inverter can produce required peak to peak V by means of a voltage doubler if need be. Big extra parts! The PWM pattern of a sinewave can be loaded into a rather small ram, rom, pal, gal, whatever. The reset of that memory device can be kicked at every instance where the inverter's signal (output) crosses 0 V and ascending. That would keep sinewave in sync with power out from inverter. This theory of operation is not complete but if components come free of cost, are you seeing any advantage here? Again, what are your thots about modi-sinwav burning up windings?
 
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