Use this forum to ask questions about excel formula, answer them or to post your own finds
Topic by Fuzz666
Are there any switched mode power supply formulas? I've been googling but I can't find anything... I need to know relation between duty cycle (I'm using square waves) frequency size (value) of the inductor output voltage output amperage how many amps should the inductor be rated for (is it how much your drawing?)
Topic by guyfrom7up | last reply
I'm designing an anemometer with Arduino and I need a formula to figure out the speed at which the rotor turns. I have a rotor with three magnets, spaced 71mm apart, triggering a Hall Effect sensor which the Arduino reads and counts. Now I can't seem to figure out a formula to calculate wind speed from this information. Anybody got an Idea (or the answer?)
Topic by smkoberg | last reply
How to find the voltage after adding a resistor with the resistance formula? For example I have a circuit that uses 0.975A and I add a 1000ohm resistor to it, if its powered by 220v main then according to V=IR what should be the voltage drop due to the resistor?
Question by Ahtasham Ahmad Mohtashim | last reply
I just want to include some formulas in my text, I've tried to edit it with a math editor, save it as a pic and paste it in the text but in the preview disappears.Thanks Massimo
Question by MassimoF11 | last reply
it is the most known formula that make it albert einstein .
Question by Waren-Neutron | last reply
Is there a mathematical formula for the arrangement of hole on a flute or better a recorder. In addition has anyone every tried to make a saxophone mouthpiece ? I am interested in trying to make a DIY version of a Xaphoon http://www.youtube.com/watch?v=j3Wnx2VYZq8
Question by rickharris | last reply
I want to formula my own potting soil - 50% soil, 50% compost, but how much perlite? And possibly substitute something else for the perlite - more "green", more natural, cheap as "dirt", just as available?
Question | last reply
Looking at a crossover inside a speaker box, I see some inductor coils and capacitors. As understand, it seems capacitors are high pass components, and inductors are the low pass components. What is the formula converting frequency in Hz into inductance of the inductor coil and/ or value of the capacitor. (I would be looking for a crossover around 30 - 40 Hz) To me, it seems logical to put this crossover not in the speaker box, but in front of the amplifiers, so the remaining audio spectrum can selectively amplified, which should result in some more power... True? (I see some recommendations for active crossovers, but the theory is way over my head).
Question by BobS | last reply
Hi. i am going to be making pcb's for some of my projects wich will include different voltages, amps etc. i am new to pcb making (although i have designed some in the past) and want to know what size i need to make my traces so that they are safe, for example: a 9v 500ma circuit will use smaller traces than a 240v 13a circuit. i was just wondering if there was a formula or website for working this out? thanks in advance - luke
Question by ljarrald | last reply
Good day I have a workbook (Attendance Register) with worksheets named for each month of the year. I would like a macro to run the 1st of every month and find the worksheet named for previous month and convert all formulas to their current value. Eg Macro to run the 1st of May and convert the formulas in worksheet April. Any help will be truly appreciated Regard Darryl
Question by DarrylJ10 | last reply
I have pigs and during the summer they get hot. I've tried misters and timer controlled sprinklers but neither suited my needs, the pigs either got ahold of the mister line and ripped it down or i just forgot to head out and turn it on and off, and the sprinkler on a timer was never right, on hot days it underwatered leaving the pen dry and dusty which is unpleasent for the pigs and on cold days it overwatered leaving the pen a muddy mess which was also unpleasant for the pigs (contrary to popular belief pigs actually don't like mud its just something cool for them to roll in and natural sunscreen. Pigs would much rather have clear water raining down on them). I decided I'm going to make a simple Arduino controlled pig sprinkler. I'm going to equip it with a temperature and humidity sensor and I want it to plug the data it gets into a formula which calculates how long it will take for the water to evaporate, it will then take that data and use it to calculate the time in between sprinkler runs. But the obvious dilemma here is I cant seem to find a formula which will work. Any help is greatly appreciated! Thanks a bunch. Harry88
Question by harry88 | last reply
I have an excel sheet, and I am trying to bring some sort of automation in to that sheet (since I use it quite often) with the help of macros. The fact is that I am really new to macros and VBA programming language, so I need a little help in writing the code to find the 10th percentile (the formula for it is PERCENTILE(array, 0.1) for each bin value (50, 100, 150). If you see the picture attached, the wanted percentile values are in Q, the bins for which I want to find the 10th percentile value, are given in Column M (50,100,150) and the main data on which the 10 percentile value will be based is given in Column D. By Using the data given in D and filtering out a certain bin width in column E (Example: Filtering bin width 50 or 100), we could find the Percentile value against each of the bin value given in Column N. As said earlier I am new to VBA code, so any help will be appreciated in order to find the percentile values for each bin. the link to the original spread sheet is given below: http://bit.ly/XCgqtK
Question by raishikoh | last reply
Although I CAN do this without the math formula(e) to figure it all out, I would like to have it for a quicker method of figuring out size, etc. so I didn't have to use up so much material in guessing. I would like to construct the tesseract I have pictured here, using rigid clear plastic sheets or panels. Given a said size for the "inner cube" say 2 inches (approx. 5 cm or about 51 mm) what formula(e) must I use to calculate the panels' dimensions to connect to the larger cube (knowing full well this will depend on the size of the larger cube....say approx. 4 inches across (about 10 cm or 102 mm)? The reason I'd like the formula(e) is that I may need to increase the size of the center cube by an inch or so, and this would allow me to do so without having to go through the "trial and error" thing so many times. I would, of course, want the center cube to be "centered", if possible or shall I say as close as possible. Thanks....
Topic by Goodhart | last reply
Thought this would be an appropriate place to share some of what i thought was interesting information to do with the area of a triangle and how numbers co-relate. To round off a square to 100cm square, one quarter of that area is 25cm square, (10cmx10cm =100/(div)25%=25cm), the area of a right angle triangle with sides measuring ~7.0710cm, equals ~25% of 100cm square, 25cm square of area, (7.0710/2=3.5355 x7.0710=24.9995205). 7.5937 if it is an equilateral triangle. it is a standard size i use, a handy measurement if you use templates for construction because it in some way represents a metric increment, thanks, Kim (the formula i used is half the base times the height, unless im mistaken i recall that is the correct formula? though i am not a full time mathamatician. for the equalateral triangle i used a web based polygon area calculator.)
Topic by QSDR | last reply
Hi all, i've got a problem with a formula in my excel spreadsheet that i'm using to get the scores for NFL teams 1978 - Current i have the data ok but the problem is with matching the the specific games. i've CONCATENATED the data to provide unique data points also it's in two columns (Home & Visitor) in the format of YearTeamW/L/DScore eg. 2012TitansW35 in the VERY unlikely event (and i've check a random selection) that the team has 2 wins at home with the same score this could cause an error. here is the formula i'm using: (version ~8000zzzzz lol) (all one formula, just added a line break to make it fit) =(IF(MATCH($A$3&$B$2&"w*",Home_Team,0)=MATCH($A$3&$C$2&"l*",Visitor,0),INDEX(Visitor,MATCH($A$3&$C$2&"l*",Visitor,0)) ,IF(MATCH($A$3&$B$2&"d*",Home_Team,0)=MATCH($A$3&$C$2&"d*",Visitor,0),INDEX(Visitor,MATCH($A$3&$C$2&"d*",Visitor,0))))) Here's a link to the folder with the spreadsheet. (NFL Stuf (test).xlsx) Sheet: Past Season Summary - what is says. eventually where the formula is going. Sheet: nfl2011lines - 92 - the data (actually 1978 - 2012 but i named it before i added all the data) Sheet: TESTING - my "sandbox" so i don't [Censored] the main sheets Semi-Related Question1 Semi-Related Question2
Question by furby | last reply
I am new to compressed air tanks. I need some details about them. (For an air car actually) 1. How to refill a 4500 psi air tank. 2. How do I know the pressure of air comming out . ( Most Important) Can anybody please provide me a schematic drawing on how do I connect the air tank, the pressure gauges (Gauge 1. which shows the pressure and amount of air in the tank and Gauge 2 which shows the pressure of air comming out) and the compressor with the copper tubes. I read on a site formula for power of an air engine is HP= PLAN / 33000 where P. Mean effective pressure in pounds per square inch. L. Stroke in feet. A. Piston area in square inches. N. Number of power strokes per minute. How do I get value of N for the formula. Thanks for any help.
Question by flyingdutchmen1659 | last reply
Hi all (again) new problem semi related to previous. (check my profile for the ones with NFL in the title) now the problem is i want to get the average score for each team in each season. my current formula only gets the first result of the index/match even if i use some of the tricks i've googled. the data is in the format of YearVisitingTeam(W/L/D)Score@HomeTeam(W/L/D)Score ie 201249ersW41@2012PatriotsL34 i use a formula to strip "Year(Visiting/Home)Team(W/L/D)" so i' left with Score on either side of the "@" (that was a [redacted] pain) using any and all of the tricks i know i get either 0, 27 or an error of some sort. the only way i've been sorta able to do this is by getting the first home win, first home loss, first away win, first away loss BUT that's only 4 of 16 games each season and not a good representation of the average points for the team in a season. the sheet in question is AVG point - Reg Season the source data is 78 - current regular season (2012 season starts @ row 3152)
Question by furby | last reply
Hello, wasn't sure where to put this, and I didn't see a beauty forum. Well. first of all. here is a formula for a lotion base that I tweaked. 8 oz distilled water 1 oz fresh aloe vera gel 1 oz floral water 1 tsp citric acid 2 oz glycerin 1 oz emulsifying wax 1 oz beeswax 1 oz shea butter 1 oz coconut oil 1 oz almond oil 1 oz avocado oil tsp essential oil 1/2 oz stearic acid I heard that 1 oz is about 2 Tbsp (tablespoons), but still not sure on this. It came out a bit thicker than I would like it. I dunno if I should add more emulsifying wax, take out the beeswax, or both. I need help making it less greasy feeling and a little thinner. I made a batch I'm not sure what to do with. I might just use it to repair those cases of dried out skin that appear around the winter season. Any suggestions?
Topic by Crystalline_Chaos
What times what divided bye
Question | last reply
I was trying to answer a question earlier and wanted to put in the formula for figuring the surface area of a sphere. Short of adding an image, I couldn't figure out how, so I just wrote out the formula. Is there a way to insert math symbols in the answer box?
Question by Burf | last reply
Question by dbird1 | last reply
Http://babel.hathitrust.org/cgi/pt?id=mdp.39015026999022 the above link is VICTORY BEGINS AT HOME! RECIPES TO MATCH YOUR SUGAR RATION this next is the correct link, tested twice. babel.hathitrust.org/cgi/pt the following is OCR generated text, but there is a PDF read on-line only there too. The link to the catalogue was posted to the Internet Archive text forums today. NOTE, The PDF can NOT be downloaded to keep, just read on line. BOOK OF FORMULAS PREPARED BY THE EDITORIAL STAFF OF POPULAR SCIENCE MONTHLY RECIPES, METHODS AND SECRET PROCESSES GROSSET & DUNLAP • Publishers • NEW YORK COPYR1GHT, 1932 AU rights reserved PUBL1SHED JANUARY, I y J 2 SECOND ED1T1ON FEBRUARY, 1934 TH1RD ED1T1ON AUGUST, 1934 »On*TH ED1T1ON JULY, 1935 PUNTED IN THE UN1TED STATES OF AMER1CA
Topic by Lateral Thinker | last reply
The world's first international hydrogen-powered motorsport race was held in Rotterdam this weekend.Dubbed the Formula Zero championship, the contest pitted teams from five countries against each other in a zero-emissions go-kart race.Each team's entry was powered by a commercial fuel cell that produces electricity from hydrogen. It may be small-scale, with only six teams entering go-kart sized vehicles, but Formula Zero is an officially-recognised motorsport, with plans for scaling up to Formula Three and the Formula One style and speeds."In 10 years if the motorsport industry as a whole hasn't engaged in zero or low emission principles, it probably won't be around," said Greg Offer, who headed up the Imperial College London team. "Teams that embrace this new technology early on will succeed, and those that don't will fall by the wayside."Racing excitement won't suffer, though; Dr. Offer says that fuel-cell powered vehicles don't represent a compromise in performance over traditional petrol-fuelled engines.'"With a combustion engine, you have to reach three or four thousand revs to get your peak power," he says. "With an electric vehicle, it's all there from standing, and they're more efficient." The next races are planned for the US in March 2009. Plenty of time to get your own entry built.Imperial TeamFormula Zero homepageBBC news article
Topic by Kiteman | last reply
Let me know about gypsum dough making method.I wanna to do table statue.Can I get the formula or method?
Question by myo win thant | last reply
The refrigerant needs a pressure differance of 1.3bar..single stage...we don hav any ideas about the material to used..the motor we use to run compressor is 100 watts..the speed can b more than 1500 rpm..we had a initial calculation far diameter of the impeller blade..but struck up with the no. of blades..we are terribly confused..so suggest us the procedures to proceed with our requireement..
Question by prakrish | last reply
I have a recipe for coca cola's secret formula. but a weapon would be nice if i encounter a assasin hired by coca cola to keep me from upgrading the formula, can anyone think of a good instructables?
Question by Trapper777 | last reply
Heey! I wanna make a .BAT program that'll help me do homework. I'm lazy to type the same formula to calculator, so I wanna make a program with preset formula. I wanna make the program solve this formula: S=3,14*r2 and O=3,14*d - Surface and Circuit of a cirle (I'm not english, my english's not the best). I wanna make the program solve these formulas. When you type r=3, it will say CIRCUIT IS (r*2 and then 3,14*'the r*2') AND SURFACE IS (3,14*r2 - the 2 should be in upper right corner) When you type d=3, it will say CIRCUIT IS (3,14*d) and SIZE IS (d:2 and then 3,14*'d:2 answer'2 - again, 2 in upper right corner. Please.......
Question by NicoFilippo | last reply
Hey I try to measure current with hall-sensor amploc 25A, it sense magnetic-fields, offset voltage is 2.5V and I use arduino uno. I get 519 value from analog pin and 37mV/A is hall sensor sensitivity. My formula is outputValue = ((((sensorValue*5000.0)/1023.0)-2500)/37 multimeter shows 0.112amps when I put load but I dont gett correct value on LCD Is my formula OK?
Topic by mattilaniko | last reply
I am going to start a small EV project. I have seen that most treadmill motors are 3 to 4hp powerful. I wanted to know weather these motors will be suitable for my project. I am building a small kart capable of carrying maximum 2 persons. Also if they are suitable for my project please can someone suggest me 3 or 4hp treadmill motors on eBay or other sites below 150$. Also I saw a formula on a site related to power for a vehicle HP = W(V/234)^3 where HP=horsepower, W=weight in pounds and V=required velocity in MPH. I found this formula on this site (http://www.ajdesigner.com/phphorsepower/horsepower_equation_trap_speed_method_horsepower.php). Is this formula correct.
Question by flyingdutchmen1659 | last reply