los? It should be "low". Android "auto-error". "Isaac M. Bavaresco" escreveu: >There are other ways to use optos without high wattage resistores. > >My suggestion to Carl uses a capacitor, since he wants to monitor AC >voltages. > >The wasted power is very los. > >Isaac > >Richard Pytelewski escreveu: >>While the LR8 is about $1. each (TO-92), it can take any DC voltage up >>to >>+450 and with 2 resistors take it to any lesser voltage (-~12v) again >>as I >>remember. 20 ma out... a handy circuit without dealing with larger >>wattage >>dropping resistors in optos. >> >>FYI... >> >>Rich >> >>-----Original Message----- >>From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On >>Behalf Of >>Carl Denk >>Sent: Monday, September 16, 2013 11:14 AM >>To: Microcontroller discussion list - Public. >>Subject: Re: [PIC} AC inputs to a PIC >> >>Thanks again for the inputs, but I should have mentioned, there will >be >>more >>than a few maybe 8 of these inputs, and any could be any of the >>voltages. >>Looking for something inexpensive and small footprint. the opto >>isolator >>fits that spec. Didn't know the details of implementing.=20 >>Thanks again. >> >>Incidentally I use a 120VAC in, 5VAC out wall wart as PIC ADC input to >>measure the AC voltage. it's a little more complicated than that, but >>works >>nicely. >>On 9/16/13 10:43 AM, David Bearrow wrote: >>> I think I would just use a small 5VDC power supply. Then you could=20 >>> detect 5V or 0V depending on if it was on or off. There are lots of=20 >>> off the shelf supplies or you could build one. >>> >>> David Bearrow >>> >>> -----Original Message----- >>> From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On=20 >>> Behalf Of Carl Denk >>> Sent: Monday, September 16, 2013 7:34 AM >>> To: PICLIST >>> Subject: [PIC} AC inputs to a PIC >>> >>> I have a home project coming down the road mainly HVAC stuff of=20 >>> digital inputs to a PIC probably a 18F??. THe inputs would be only >to >> >>> sense on/off. The voltages would be 24 VAC, 120 VAC, and 240 VAC. >I'm >> >>> thinking through an Opto isolator with a resistor and capacitor on >>the AC >>side. >>> Values ? Configuration? or something else? >>> >>> This is a low priority at the moment, but thought I would generate=20 >>> some traffic for Bob. :) >>> >>> Thanks again. >> >>-- >>http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >>View/change >>your membership options at >>http://mailman.mit.edu/mailman/listinfo/piclist >> >>--=20 >>http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >>View/change your membership options at >>http://mailman.mit.edu/mailman/listinfo/piclist > >--=20 >E-mail enviado do meu celular Android usando K-9 Mail. Por favor, >desculpe minha brevidade. >--=20 >http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >View/change your membership options at >http://mailman.mit.edu/mailman/listinfo/piclist --=20 E-mail enviado do meu celular Android usando K-9 Mail. Por favor, desculpe = minha brevidade. --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .