Yet another voltage divider calculator. - Page 1
Forum section: electronics / general

author: SirDan
author_rank: Contributor
timestamp: May 09, 2015, 04:40:04 pm
content: This may be useful for beginners.A web based two resistor voltage divider calculator and some basic info.http://www.voltagedivider.ca/Thanks,Dan.

author: c4757p
author_rank: Super Contributor
timestamp: May 09, 2015, 05:25:01 pm
content: I don't understand this sort of thing. Who can't divide and multiply?

author: zapta
author_rank: Super Contributor
timestamp: May 09, 2015, 05:42:48 pm
content: Quote from: c4757p on May 09, 2015, 05:25:01 pmApparently it's not for you.

author: tom66
author_rank: Super Contributor
timestamp: May 09, 2015, 06:35:44 pm
content: You don't even need to divide or multiply, you can just see ratios, and get an approximation or exact result. 1V in, 100kohm top, 200kohm bottom: 2/3rds across bottom resistor, 0.66V out. etc. Takes 5 seconds to do in your head.The more useful calculators are ones where you can input an output voltage and input voltage and then choose two standard values that get the result within x%. That is hard to do in your head. (Well, for me at least... maybe I'm just a simpleton)

author: Fsck
author_rank: Super Contributor
timestamp: May 09, 2015, 06:39:50 pm
content: Quote from: zapta on May 09, 2015, 05:42:48 pmbut seriously, anyone even remotely into electronics should be able to do a simple voltage divider without the web.

author: JacquesBBB
author_rank: Frequent Contributor
timestamp: May 09, 2015, 06:49:19 pm
content: QuoteThis is even misleading. Why not say "The formula is VOUT = VIN * (R2 / (R1 + R2))".As it is written, one may think that " VOUT = VIN * (R2 / (R1 + R2))" is just an approximation of the more complete formula that is used in this web interface.

author: c4757p
author_rank: Super Contributor
timestamp: May 09, 2015, 07:09:48 pm
content: Quote from: zapta on May 09, 2015, 05:42:48 pmNor for anyone else intelligent enough to have a need for it...

author: tom66
author_rank: Super Contributor
timestamp: May 09, 2015, 07:14:00 pm
content: Quote from: JacquesBBB on May 09, 2015, 06:49:19 pmWell, it is an approximation... it assumes electric current is a continuous quantitiy, when it's really discrete in nature represented by individual electrons. Below a few hundred attoamperes (10e-18) the error will increase significantly.

author: Zero999
author_rank: Super Contributor
timestamp: May 09, 2015, 08:10:20 pm
content: Quote from: tom66 on May 09, 2015, 07:14:00 pmThat's known as shot noise and depends on the bandwidth, as much as the current - Amperes is a measure of Coulombs per second.http://en.wikipedia.org/wiki/Shot_noiseQuote from: tom66 on May 09, 2015, 06:35:44 pmI agree but there are more silly webpages about such as the charts for converting between picofarads, nanofarads, microfarads etc.

author: SirDan
author_rank: Contributor
timestamp: May 09, 2015, 08:42:23 pm
content: Quote from: Hero999 on May 09, 2015, 08:10:20 pmSuch as this one:http://www.uf-nf-pf.com/index.php

author: skipjackrc4
author_rank: Regular Contributor
timestamp: May 09, 2015, 10:46:06 pm
content: Quote from: SirDan on May 09, 2015, 08:42:23 pmI didn't even know that this existed.

author: Jeroen3
author_rank: Super Contributor
timestamp: May 09, 2015, 10:56:42 pm
content: I once found a website capable of entering a ratio, and it would show you all the possible combinations of E-range resistors to use. Including the error percentage.Havent found it again since.. forgot to ctrl-d

author: Zero999
author_rank: Super Contributor
timestamp: May 09, 2015, 11:17:55 pm
content: Quote from: Jeroen3 on May 09, 2015, 10:56:42 pmhttp://jansson.us/resistors.htmlhttp://www.random-science-tools.com/electronics/divider.htm

author: tom66
author_rank: Super Contributor
timestamp: May 09, 2015, 11:27:23 pm
content: I made this one a while ago for my personal use.http://www.toms-service-manuals.com/Utilities/VoltDivCalc.php

author: amyk
author_rank: Super Contributor
timestamp: May 10, 2015, 05:27:27 am
content: Quote from: skipjackrc4 on May 09, 2015, 10:46:06 pmAgreed on the! Anyone who needs to use such a thing shouldn't be doing anything with electronics...

author: Jeroen3
author_rank: Super Contributor
timestamp: May 10, 2015, 11:37:59 am
content: Quote from: Hero999 on May 09, 2015, 11:17:55 pmVery useful. But not the same. The internet is very big...I also use this tool sometimes of you have to stack some smd resistors to get some fancy value.http://www.qsl.net/in3otd/parallr.html

author: zapta
author_rank: Super Contributor
timestamp: May 10, 2015, 02:39:22 pm
content: Quote from: Fsck on May 09, 2015, 06:39:50 pmUsing the web is not a bad thing that should be avoided.I do most of my calculations on the web. Wolfram, Google calculator, unit converters, Linux timestamps, regex, decimal to hex, and even online spreadsheets. That's the beauty of the web.