Why don’t you just use a 3 volt relay ?
I have several on order from Digikey. I am basically doing what you are attempting. I am driving a 3 volt relay from an I/O port. The trick is to use the Digikey Search feature to look for a 3 volt relay and NOT a 3.3 version. If you use a 3 volt relay then the Vce voltage drop of the transistor will not affect the relay. (turn on is usually ~2.5v) They also come with built in diodes J Bill From: [email protected] [mailto:[email protected]] On Behalf Of Carlos Cesario Sent: Thursday, January 01, 2015 3:03 PM To: [email protected] Subject: Re: [beagleboard] Re: Gpio Relay Hello Tux Leonard, thank you by your answer. Using +5v I had success too, but I would like to usage only +3v and convert it to +5v like this circuit http://electronics.stackexchange.com/questions/56093/how-to-use-a-3v-output-to-control-a-5v-relay But I 'm having difficult understand this and simulate with BBB or RPi If possibe, could you help me pls? Thank you o much and happy new year for everyone!!!! Carlos Em quinta-feira, 1 de janeiro de 2015 17h00min02s UTC-2, Tux Leonard escreveu: Perhaps you can google for "MOSFET as Switch" I attached my solution. The relay should be connected to the end of the blue line and +5V. To protect your circuit you could add a diode in parallel to the relay. 2015-01-01 17:32 GMT+01:00 Carlos Cesario <[email protected] <javascript:> >: Hello guys! It is wrong!!! Does nos working as expected. :( Does someone could instruct me how todo this ? 3v to 5 using 2n7000 .. Thank you! Carlos Em quarta-feira, 24 de dezembro de 2014 22h13min50s UTC-2, Carlos Cesario escreveu: Hello guys, Someone please could help/explain me how isthe best and security way to connect 5v relays on BBB ? I 'm planning usage this relay http://www.dx.com/en/p/arduino-5v-relay-module-blue-black-121354 or this relay board http://www.dx.com/en/p/8-channel-5v-relay-module-board-for-arduino-red-156424 Thank you Best regards, Carlos -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected] <javascript:> . For more options, visit https://groups.google.com/d/optout. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout. _____ No virus found in this message. Checked by AVG - www.avg.com Version: 2015.0.5577 / Virus Database: 4257/8807 - Release Date: 12/25/14 Internal Virus Database is out of date. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
