---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 08/03/17: 6 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:35 AM - Re: Starter Solenoid Diode (user9253) 2. 07:20 AM - Re: Re: Starter Solenoid Diode (William Hunter) 3. 07:57 AM - Re: Starter Solenoid Diode (user9253) 4. 08:21 AM - Re: Re: Starter Solenoid Diode (William Hunter) 5. 08:38 AM - Re: Starter Solenoid Diode (Robert L. Nuckolls, III) 6. 08:47 AM - Re: Starter Solenoid Diode (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 06:35:00 AM PST US Subject: AeroElectric-List: Re: Starter Solenoid Diode From: "user9253" I had the same concerns as Charlie but did not say anything because I was not sure. After sleeping on it, connecting an inductive load (starter) in parallel with a Dynon input might not be a good idea. I suggest that input be used instead for the Air filter door position sensor. That diode will NOT protect the Dynon input from an inductive voltage spike. Notice that the diode and Dynon input combination are connected in parallel with the inductor (starter). And the banded end of the diode is connected to positive. That is the same orientation as arc suppression diodes. Therefore the diode will conduct inductive spikes right through the Dynon input. The Dynon manual states, "The voltage on the general purpose inputs must not exceed 15 volts." I would call Dynon support before connecting an inductive load in parallel with an input. If Dynon gives the OK, would the circuit actually work? I assume the Dynon input supplies 5 volts through a pull-up resistor. The input will be normally grounded through the starter motor. When the contactor is energized, Dynon input current will stop flowing because the load (starter) will draw current from the highest voltage source which is the aircraft battery. The Dynon input will then go high from the 5 volt pull-up resistor. Like I said, I am not sure. I will not be insulted if someone corrects me. Opposing views encouraged. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=471472#471472 ________________________________ Message 2 _____________________________________ Time: 07:20:07 AM PST US From: "William Hunter" Subject: RE: AeroElectric-List: Re: Starter Solenoid Diode Joe and Charlie, As always I am VERY GRATEFUL for your time and help!!! I will call Dynon today as soon as they open. As Joe recommends, I might just eliminate the "I" post input to the Dynon and roll (err...fly) with a simple LED next to the starter pushbutton. As Joe was hitting send I was studying the AeroElectric diagrams. Regardless of what I do with the "I" post, I still need an external diode on my Ford starter solenoid. I assume that the external diode needs to run from the "S" pole to the solenoid case ground (a composite airplane) with the banded end closest to the "S" pole as shown in the attached schematic). Can you PLEASE look it over and make sure I got it right. > I assume the Dynon input supplies 5 volts through a pull-up resistor. This whole "Pull Up" resistor thing is confusing. The sensor inputs of the Dynon EMS show 5 VDC. Here is a quote from the Dynon Tech Support on one of the threads " The pin is pulled up internally to 5V. This means it's 5V when nothing is connected and some path to ground is needed to reduce the voltage below 5V. So you get 5V when nothing is connected and 0V when you connect the wire to ground. This isn't "magic," it's just a 10K resistor to 5V." .. THANKS AGAIN!!! Bill Hunter ________________________________ Message 3 _____________________________________ Time: 07:57:12 AM PST US Subject: AeroElectric-List: Re: Starter Solenoid Diode From: "user9253" Bill, yes the diode is connected correctly. It is directly across the coil with the banded end on the positive side. About pull-up resistors: The only way that an input can tell if a switch is open or closed is by sending a small current through the switch. Current flows when the switch is closed and current stops when the switch is open. The current must be limited to protect the 5 volt source and to protect the wires. A 10K series resistor limits the current. That resistor is called a pull-up resistor. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=471475#471475 ________________________________ Message 4 _____________________________________ Time: 08:21:21 AM PST US From: "William Hunter" Subject: RE: AeroElectric-List: Re: Starter Solenoid Diode Thanks Joe!!! Very clear explanation...You would make an excellent electronics instructor!!! Thankfully there is still a Radio Shack in town...limited components but I hope they will have the Dye-Oh-doe I need. .. Cheers!!! Bill Hunter -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of user9253 Sent: Thursday, August 3, 2017 7:57 AM Subject: AeroElectric-List: Re: Starter Solenoid Diode Bill, yes the diode is connected correctly. It is directly across the coil with the banded end on the positive side. About pull-up resistors: The only way that an input can tell if a switch is open or closed is by sending a small current through the switch. Current flows when the switch is closed and current stops when the switch is open. The current must be limited to protect the 5 volt source and to protect the wires. A 10K series resistor limits the current. That resistor is called a pull-up resistor. -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=471475#471475 ________________________________ Message 5 _____________________________________ Time: 08:38:41 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Starter Solenoid Diode At 09:07 PM 8/2/2017, you wrote: > > >My Spanish uncle would call it a =93Dye-Oh-Doe=94 >and I know I need one however I do not know what value nor where to install it. > >I want an indicator on my EMS to monitor the >starter motor being energized and a cyber friend >recommended installing a 1N4004 diode on my =93I=94 >pole of my starter solenoid to protect the Dynon >EMS sensor and he drew up the attached PDF >diagram and I will certainly do as he recommends. > >The additional question is=85can someone also >provide me with a quick schmatic of what diode I >should use and where and what polarity to >install it to protect from electrical spikes (in >the same manner as one does for master contactors)? > >.. > >THANKS GUYS=85I am making progress this week (for a change)!!! > >Bill Hunter Can't imagine why . . . if your EMS has inputs designed to attach to any source of power on the airplane for the purposes of monitoring (voltmeter input) then just tie it to the "I" terminal directly. The diode as he as shown it would actually prevent the EMS from seeing voltage on the "I" terminal. Bob . . . ________________________________ Message 6 _____________________________________ Time: 08:47:42 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Starter Solenoid Diode At 10:38 AM 8/3/2017, you wrote: >At 09:07 PM 8/2/2017, you wrote: >> >> >>My Spanish uncle would call it a =93Dye-Oh-Doe=94 >>and I know I need one however I do not know what value nor where to install it. >> >>I want an indicator on my EMS to monitor the >>starter motor being energized and a cyber >>friend recommended installing a 1N4004 diode on >>my =93I=94 pole of my starter solenoid to protect >>the Dynon EMS sensor and he drew up the >>attached PDF diagram and I will certainly do as he recommends. >> >>The additional question is=85can someone also >>provide me with a quick schmatic of what diode >>I should use and where and what polarity to >>install it to protect from electrical spikes >>(in the same manner as one does for master contactors)? >> >>.. >> >>THANKS GUYS=85I am making progress this week (for a change)!!! >> >>Bill Hunter > > Can't imagine why . . . if your EMS has inputs designed to > attach to any source of power on the airplane for the purposes > of monitoring (voltmeter input) then just tie it to the "I" > terminal directly. The diode as he as shown it would actually > prevent the EMS from seeing voltage on the "I" terminal. Oh, okay. If the input port to the Dynon is NORMALLY looking for a 0-5v signal, then yes . . . as Joe has pointed out, a pull-up resistor on the Dynon side of the diode is needed to raise the input to approx 5v when the "I" terminal RISES ABOVE 5v (starter getting power from battery). If, in this case, the EMS input is tailored to 0-5v sensor inputs, then it may NOT be protected internally for general used looked at voltages elsewhere on the system. Do check with Dynon as to absolute maximums that the input will tolerate. Bob . . . ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.