SparkFun Electronics Commentsurn:uuid:214d0e4e-f1b1-d287-ce26-ac5b4c9f82492024-03-28T15:37:39-06:00SparkFun ElectronicsCustomer #999887 on Enginursday: Battery ManagementCustomer #999887urn:uuid:508fd024-4f8a-a4a5-af55-14e3718046c32017-05-22T06:23:50-06:00<p>The Battery Babysitter must be able to go into SYSOFF mode. We’ll test this by measuring the off current through the battery terminal.<p>maybe you can give a picture on this</p></p>
MTaylor on Enginursday: Battery ManagementMTaylorurn:uuid:3fcc24e6-71c5-c1a5-750c-24b2d3606bba2017-03-27T13:58:25-06:00<p>Thanks! But this is 2017 so it's actually a digital coffee ring that has white sent to transparency, which was overlaid on the original. ;)</p>
MTaylor on Enginursday: Battery ManagementMTaylorurn:uuid:126a3ee8-256d-428f-90a9-ede4bc66a8e72017-03-27T13:57:22-06:00<p>The ANSI Y32.2 is easy to find, thanks! I actually prefer the 1975 version, as the symbols are not space over pages and pages. I'll keep this one around!<p>I'm not sure of the legality either, but it floods the google results. I wish these standards were made with the intent to be open source to aid humanity!</p></p>
Sembazuru on Enginursday: Battery ManagementSembazuruurn:uuid:3a9c439b-1860-139f-061e-3b032cd640472017-03-24T08:38:21-06:00<p>Nice. You remembered to put in the requisite coffee mug ring on your hand drawn schematic. Very classy. :-D</p>
Sembazuru on Enginursday: Battery ManagementSembazuruurn:uuid:3e86423f-6d4f-baba-3e87-fdb249af41dd2017-03-24T08:29:09-06:00<p>While we are being pedantic, it isn't just MOSFETs that use the term "gate" for the controlling pin. AFAIK it's both MOSFETs and JFETs (though I haven't seen a JFET outside of class many solar orbits ago.) Also, don't most thyristors use "gate"?<p>Hmmm... I don't want to spend too much time here at work researching this, but do any of the other simple solid state devices other than the BJT use "base"?</p></p>
Sembazuru on Enginursday: Battery ManagementSembazuruurn:uuid:e1f23bd8-aad9-2e67-9223-88b9d736716d2017-03-24T08:24:47-06:00<p>It isn't well known, but the symbol(s) for switches is(are) actually quite extensive with different bits meaning different things. Kind of like letters in languages that heavily use <a href="https://en.wikipedia.org/wiki/Diacritic" rel="nofollow">diacritics</a> (unlike english).<p>If you take a critical look at the symbols on <a href="http://www.electronic-symbols.com/electric-electronic-symbols/switch-symbols.htm" rel="nofollow">this</a> page you should start to see variations of the basic symbol along with modifiers that specify things like what causes the switch to change state. If you really want to see all sorts of modifiers and how they can be applied, dig up a copy of IEEE Std 315 (also ANSI Y32.2) and look at Section 4. (I have a pdf of the 1975 version (reaffirmed in 1993), but I don't remember where I found it other as a result of a google search. I don't know the legality of it since I never paid for it, but as a hobbyist I really can't justify the cost of the standards from any of the standards organizations.)</p></p>
MTaylor on Enginursday: Battery ManagementMTaylorurn:uuid:923b79d8-567e-3701-59e1-2c86d4eaae5c2017-03-23T12:09:58-06:00<p>Low was indeed intended to be high, I have fixed it. Thanks!<p>The button thing is an interesting point. I've been drawing them that way for years and no one has said anything, but sure enough the T is supposed to go the other way, or, I should have just drawn it as a line.</p></p>
MTaylor on Enginursday: Battery ManagementMTaylorurn:uuid:dd9c7ecf-714f-0857-7be5-b2419ef33edc2017-03-23T10:17:35-06:00<p>To be honest, that one gets me too sometimes.<p>OK, I think I got it a little clearer in the post now.</p></p>
dksmall on Enginursday: Battery Managementdksmallurn:uuid:164fecc7-d3a3-d9a2-3eb4-0d006860ea702017-03-23T10:10:56-06:00<p>LOL yes a base, you got me there!</p>
MTaylor on Enginursday: Battery ManagementMTaylorurn:uuid:284ff8ae-3da1-6d39-4820-a28d686777192017-03-23T10:08:55-06:00<p>Your analysis is correct! I was a bit high-level with that sentence though, and left out words! I'll go in and see if I want to reword the section a bit.<p>Maybe it should read:
"The (processor) can pull the (SYSOFF) line low (by driving its GPIO high) to turn the system on."</p><p>Also, because we're talking about words and meaning, BJTs have a base, mosfets have a gate! ;)</p><p>Thanks for the comment!</p></p>
dksmall on Enginursday: Battery Managementdksmallurn:uuid:0fcb5726-63c7-fd5f-26a3-d9da545e4aec2017-03-23T09:47:32-06:00<p>" or the GIPO output can pull the line low to turn the system on." I see an NPN open collector driver, shouldn't the gate be driven high (via GPIO) to enable the transistor to drive the SYSOFF signal low? Or maybe that's what you meant and it's just the wording that threw me off.</p>