On Thursday 27 December 2012 20:34:35 Florian Rist did opine: > Hi Gene, > somehow I don't relay understand your problem, but... > > > Sparkfun put an op-amp on the chip output to make it more > > sensitive, but for my purposes, it should have been a comparator. > > You can easily rewire the existing circuit to be a comparator. > > See > > > http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Sensors/Current/ACS712%20 > Low%20Current%20Sensor%20Board%20v14.pdf
Have you looked at that board scaled? I almost need a magnifying glass to find it in the box they shipped it in. The whole board is half a square inch & maybe some small change. > and break the connection between the output and R1 and C1. That's likely the easiest, thanks. > Or to get a comparator with a adjustable hysteresis additional rewire R3 > to get an adjustable resistor between the output and the positive input > of the amplifier. > > The current the circuit draws highly depends on the impedance of the > input you connect the output to. The OPA344 its self only draw 150 µA > (max. 250) but can deliver up to 15 mA (max. 30 at high temperatures). > > The ACS713 draws 10 to 13 mA with open output. > > So you end up with 13 mA min. to 30 mA (in worst case around 45) > depending on the load at the output. Good to know. > See you > Flo Thanks Florian. Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> is up! Support the Girl Scouts! (Today's Brownie is tomorrow's Cookie!) I was taught to respect my elders, but its getting harder and harder to find any... ------------------------------------------------------------------------------ Master HTML5, CSS3, ASP.NET, MVC, AJAX, Knockout.js, Web API and much more. Get web development skills now with LearnDevNow - 350+ hours of step-by-step video tutorials by Microsoft MVPs and experts. SALE $99.99 this month only -- learn more at: http://p.sf.net/sfu/learnmore_122812 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
