Hello Tom, Inputting your data into my electronics simulator, a 120 volt relay at 3.5 va, 1700 ohms, 1.44 watts reads 0.012 amps at 120 vac input.
At 240 volts, I had to increase the power resistor up to 10K ohms to read 119.403 volts at 0.012 amps or 1.4328 watts. Close enough. Roland ----- Original Message ----- From: tomw<mailto:[email protected]> To: [email protected]<mailto:[email protected]> Sent: Friday, September 20, 2013 8:00 PM Subject: [EVDL] relay coil V I am using a relay with 120VAC coil as a "charger relay" - it turns off 12V when AC is connected to the charger so the car cannot be moved. J1772 does not have neutral so the coil must be driven by 240VAC for it to work with J1772. The relay coil is rated at 3.5 VA, 1700 Ohm, 1.44W dissipation. I connected a 4kOhm 10W power resistor in series with the coil and get 144VAC across the coil, about 20% higher than rated voltage. Specs say up to 110% rated coil voltage. Instead of running about 29 mA through the coil I will be running about 35 and dissipating about 2 W rather than 1.44W. Think this will shorten the coil life significantly? Should I purchase a 5.8k 10W power resistor? -- View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/relay-coil-V-tp4665255.html<http://electric-vehicle-discussion-list.413529.n4.nabble.com/relay-coil-V-tp4665255.html> Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com. _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub<http://www.evdl.org/help/index.html#usub> http://lists.evdl.org/listinfo.cgi/ev-evdl.org<http://lists.evdl.org/listinfo.cgi/ev-evdl.org> For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA<http://groups.yahoo.com/group/NEDRA>) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20130920/ec48fed8/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
