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| Modern way to specify values on schematics |
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| jpanhalt:
--- Quote from: ebastler on March 05, 2019, 11:47:25 am --- --- Quote from: jpanhalt on March 05, 2019, 10:41:22 am ---Interesting how so many feel they are using the SI system, often called the metric system, but don't follow its rules. --- End quote --- You are confusing the SI system of units with the typesetting rules for writing numbers and (whichever) units. --- End quote --- I wrote SI "system." That system defines printing format among many other things. No confusion on my part. Here is a link to a primary source: https://www.bipm.org/en/publications/si-brochure/ |
| bitbanger:
This somewhat humorously reminds me I once use the R separator in a project (i.e. 47R) I was worried about distiller/render compatibility issues and the ohm symbol. My supervisor at the time lost her mind over it, "we just don't do that here". ;D |
| Wimberleytech:
--- Quote from: robertbaruch on March 03, 2019, 07:12:18 pm ---I follow a few rules: 1. Never use a decimal point. Sometimes it doesn't show up, and is easily missed. In place of the decimal point, use the magnitude. Try to avoid leading zeros if possible. BAD: 1.2k GOOD: 1k2 BAD: 0.1u GOOD: 0u1 BETTER: 100n 2. Never use the unit, only the magnitude, EXCEPT when the magnitude is unity. This is just practical, because you really don't want to use any more space than you have to. The schematic symbol itself shows you what the component is. Resistances are always in ohms, capacitances in Farads, inductances in Henries. For ohms, use "R". Corollary to #2: I prefer to use the IEC symbol for resistors, which is a rectangle. The value goes inside the rectangle instead of next to the symbol. BAD: 1kΩ GOOD: 1k BAD: 1.2Ω GOOD: 1R2 BAD: 22pF GOOD: 22p 3. Never use the micro character. Instead, use "u". BAD: 22µ GOOD: 22u As for the question about resistor values, the primary purpose of a schematic is to convey information, so it needs to be as visually pleasant as possible. Lines which cross every which way are bad. Even multiple parallel lines for a bus isn't great, use a thicker bus line instead. Signals should generally flow from left to right. Use subsystems if things get too busy. So, if adding component values would clutter up the diagram, it's reasonable to put them in a table off in the corner. Use notes to explain the values. --- End quote --- Ditto...and NEVER USE FOUR-WAY CONNECTIONS. NEVER USE DOTS to indicate a connection. |
| ebastler:
--- Quote from: jpanhalt on March 05, 2019, 12:14:27 pm ---I wrote SI "system." That system defines printing format among many other things. No confusion on my part. Here is a link to a primary source: https://www.bipm.org/en/publications/si-brochure/ --- End quote --- Thanks, I learned something new! I will limit my claim to "I am using SI units" going forward. ;) |
| ebastler:
--- Quote from: Wimberleytech on March 05, 2019, 01:37:34 pm ---NEVER USE FOUR-WAY CONNECTIONS. NEVER USE DOTS to indicate a connection. --- End quote --- I agree with the "no four-way junctions". But for three-way junctions, don't pretty much all CAD systems use dots to indicate junctions, and don't DIN, IEC etc. require them in schematics? |
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