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| Thread ID: 56664 | 2005-04-11 23:59:00 | XL Formula - (with a twist) | B.M. (505) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 343953 | 2005-04-11 23:59:00 | I thought I’d design a very simple little spreadsheet for calculating the total resistance of resistors in parallel. Yep, simple enough to do longhand, or with a calculator, but not as simple as I thought to design a spreadsheet. Well, not for me anyway. Its real usefulness would be for resistors containing decimal points. (eg 4.7ohms etc) Anyway, lets say we have four resistors in parallel of 10, 20, 30 & 40 ohms. Ok, the formula is 1/r1 + 1/r2 + 1/r3 + 1/r4 = 1/R or 1/10 + 1/20 + 1/30 + 1/40 = 1/R The first complication is that we don’t always have 4 resistors, sometimes there may be just 2 or 3 and we can’t multiply by zero. (This is where my design fell to pieces). Ok all you NZCEA scholars, I expect this to be sorted double quick or I’ll have to pass all of you! :rolleyes: By the way, the answer to the above equation is 4.8 ohms I think. :) |
B.M. (505) | ||
| 343954 | 2005-04-12 00:20:00 | Try this site www.elecdesign.com |
Speedy Gonzales (78) | ||
| 343955 | 2005-04-12 00:55:00 | I’m suitably impressed with the site Speedy but regretfully their extensive formula is not for resistors in parallel. Well worth the XL guru’s on this site having a look though. What I’m trying to achieve is probably far to simple for those guys. :) |
B.M. (505) | ||
| 343956 | 2005-04-12 01:11:00 | What about the formula here? www.montek.com |
Speedy Gonzales (78) | ||
| 343957 | 2005-04-12 01:24:00 | Now that looks exactly what I’m looking for Speedy but I can’t open the spreadsheet . :confused: I just get a square box with one of those little boxes containing a square a circle and a triangle in the corner . Can’t remember what that indicates . :blush: |
B.M. (505) | ||
| 343958 | 2005-04-12 01:31:00 | Hmm u mean the spreadsheet on this page?? It doesnt show in Opera. BUT it does show in IE. Are you using IE to view that site?? |
Speedy Gonzales (78) | ||
| 343959 | 2005-04-12 02:33:00 | Yep Speedy, everything's fine except the spreadsheet and yes I am using IE. Wonder what goes on? |
B.M. (505) | ||
| 343960 | 2005-04-12 02:39:00 | Try going into internet options/advanced / restore to defaults . See if that fixes it . I think it has something to do with the pics why u see nothing . |
Speedy Gonzales (78) | ||
| 343961 | 2005-04-12 02:46:00 | If all u want is a site with a calculator on it, type parallel resistor calculator in google or yahoo . There's a lot of sites, that do the same thing as the site I pasted . |
Speedy Gonzales (78) | ||
| 343962 | 2005-04-12 02:54:00 | I'd prefer it in XL Speedy, as I can have it on my laptop and use it when an Internet connection is not available . This is the first time I've struck a site where I can't view something . :mad: Yep, I've googled and googled without result yet . :( Cheers Bob |
B.M. (505) | ||
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