That would be one option. Another option is for the magnet to hold the reed switch closed when the door is closed. Thus your application could turn on the screen if the signal is interrupted and turn off the screen if the circuit is complete. If you are running the signal to an input pin, you just need a current limit resistor and two wires and a 5v source.
Phil On Tue, Oct 5, 2021 at 5:08 PM Cor van de Water via EV <ev@lists.evdl.org> wrote: > Phil, > You mean when the magnet is mounted in a way that is passes by the > reed relay while opening/closing the fuel door, so that with the door > open and closed, the reed relay does not make contact, only while > opening/closing when the magnet passes by the relay? > Cor. > > On Tue, Oct 5, 2021 at 5:02 PM Phil Hochstetler via EV > <ev@lists.evdl.org> wrote: > > > > reed switch with a magnet on the fuel door would do the trick. > > > > Phil > > > > On Tue, Oct 5, 2021 at 2:25 PM Bill Dennis via EV <ev@lists.evdl.org> > wrote: > > > > > Thanks. The application is not critical, just turning on a screen. > So I'd > > > like to stick with a simple, non-powered switch. > > > > > > Bill > > > > > > -----Original Message----- > > > From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Peri Hartman > via > > > EV > > > Sent: Tuesday, October 5, 2021 3:16 PM > > > To: Electric Vehicle Discussion List > > > Cc: Peri Hartman > > > Subject: Re: [EVDL] Momentary Pulse Switch > > > > > > That sounds like a fail prone solution. If you get noise or somehow > lose > > > a pulse, you'll be out of synch. Wouldn't it be better to simply poll > > > the sensor once in a while ? Or have both: a pulse when the state > > > changes and a method to poll to confirm the state ? > > > > > > Peri > > > > > > << Annoyed by leaf blowers ? https://quietcleanseattle.org/ >> > > > > > > ------ Original Message ------ > > > From: "Bill Dennis via EV" <ev@lists.evdl.org> > > > To: "'Electric Vehicle Discussion List'" <ev@lists.evdl.org> > > > Cc: "Bill Dennis" <e...@q.com> > > > Sent: 05-Oct-21 13:16:07 > > > Subject: [EVDL] Momentary Pulse Switch > > > > > > >Can someone recommend a small, momentary pulse switch for 5 volts? > When > > > the car's fuel door is opened, I want a the switch to close to send a > quick > > > pulse, then turn off. Same when the fuel door is closed. The switch > > > doesn't have to handle anything more than milliamps. > > > > > > > >Thanks, > > > > > > > >Bill Dennis > > > > > > > >_______________________________________________ > > > >Address messages to ev@lists.evdl.org > > > >No other addresses in TO and CC fields > > > >UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > > > >ARCHIVE: http://www.evdl.org/archive/ > > > >LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > > > > > > _______________________________________________ > > > Address messages to ev@lists.evdl.org > > > No other addresses in TO and CC fields > > > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > > > ARCHIVE: http://www.evdl.org/archive/ > > > LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > > > > > > _______________________________________________ > > > Address messages to ev@lists.evdl.org > > > No other addresses in TO and CC fields > > > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > > > ARCHIVE: http://www.evdl.org/archive/ > > > LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > > > > > -------------- next part -------------- > > An HTML attachment was scrubbed... > > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20211005/42a14fe4/attachment.html > > > > _______________________________________________ > > Address messages to ev@lists.evdl.org > > No other addresses in TO and CC fields > > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > > ARCHIVE: http://www.evdl.org/archive/ > > LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > _______________________________________________ > Address messages to ev@lists.evdl.org > No other addresses in TO and CC fields > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > ARCHIVE: http://www.evdl.org/archive/ > LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20211005/a3bf0937/attachment.html> _______________________________________________ Address messages to ev@lists.evdl.org No other addresses in TO and CC fields UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/ LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org