---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 06/17/14: 13 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 01:06 AM - Re: LED Ghosting (donjohnston) 2. 03:57 AM - Re: LED Ghosting (user9253) 3. 06:38 AM - Re: Re: LED Ghosting (Charlie England) 4. 07:56 AM - Re: LED Ghosting (donjohnston) 5. 10:07 AM - Re: LED Ghosting (user9253) 6. 10:08 AM - Re: Re: LED Ghosting (Robert L. Nuckolls, III) 7. 11:21 AM - Re: Re: LED Ghosting (Roger & Jean) 8. 11:24 AM - Re: Re: LED Ghosting (Robert L. Nuckolls, III) 9. 12:07 PM - Re: LED Ghosting (donjohnston) 10. 12:36 PM - Re: Re: LED Ghosting (rayj) 11. 01:26 PM - Re: Re: LED Ghosting (Lyle Peterson) 12. 02:44 PM - Re: LED Ghosting (donjohnston) 13. 04:29 PM - Re: LED Ghosting (user9253) ________________________________ Message 1 _____________________________________ Time: 01:06:48 AM PST US Subject: AeroElectric-List: Re: LED Ghosting From: "donjohnston" Yep. "The engine analyzer people said it was designed for incandescent and to put a 1.5k resistor across the LED. " Read this topic online here: http://forums.matronics.com/viewtopic.php?p=424993#424993 ________________________________ Message 2 _____________________________________ Time: 03:57:37 AM PST US Subject: AeroElectric-List: Re: LED Ghosting From: "user9253" Does the LED have a series resistor? If so, what is its value? Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=424997#424997 ________________________________ Message 3 _____________________________________ Time: 06:38:27 AM PST US From: Charlie England Subject: Re: AeroElectric-List: Re: LED Ghosting On 6/17/2014 3:04 AM, donjohnston wrote: > > Yep. > > "The engine analyzer people said it was designed for incandescent and to put a 1.5k resistor across the LED." > > What kind of LED are you using? Is it one designed to run directly on 12V (meaning it already has an internal current limit resistor)? ________________________________ Message 4 _____________________________________ Time: 07:56:52 AM PST US Subject: AeroElectric-List: Re: LED Ghosting From: "donjohnston" > Does the LED have a series resistor? If so, what is its value? > Joe Yes. 390ohm (see attached). What kind of LED are you using? Is it one designed to run directly on 12V (meaning it already has an internal current limit resistor)? No. See above. There's nothing wrong with any of the other LEDs. It's just the one for the engine analyzer. The analyzer is allowing some current through when it's off. With an incandescent bulb, this is not a problem. With an LED, it is. Putting a 1k resistor solves the dimly lit LED but it make the LED dimmer than the rest. So I'm trying to solve two possible problems. 1) Keep the engine analyzer alarm LED from being partially lit when it should be off, and 2) have the LED at the same brightness as the other LEDs. Now it's possible (more like probable) that I'm going to have the exact same problem with the Low Voltage warning since the LR3C voltage regulator is designed for an incandescent bulb also. But I haven't gotten to the point where I can start the engine so I don't know yet. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=425013#425013 Attachments: http://forums.matronics.com//files/warning_circuit_109.pdf ________________________________ Message 5 _____________________________________ Time: 10:07:14 AM PST US Subject: AeroElectric-List: Re: LED Ghosting From: "user9253" I suggest that you put a 1.5k resistor across the LED per the engine analyzer people. Then replace the 390 ohm series resistor with a 330 ohm resistor. Or experiment with different values (all less than 390) to get the desired brightness. Or put a pot in series with the dim LED and turn the pot until the current though the dim LED is equal to the current through one of the other LEDs. Then substitute a fixed resistor for the pot. 40 years ago I could have calculated the resistor value. Now trial and error is easier. :-) Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=425024#425024 ________________________________ Message 6 _____________________________________ Time: 10:08:53 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: LED Ghosting At 09:55 AM 6/17/2014, you wrote: > > > > Does the LED have a series resistor? If so, what is its value? > > Joe > >Yes. 390ohm (see attached).\ Ooops, two LED's in series . . . should have asked about that. Okay, I suggest we pay homage to our teachers one of whom once opined: ". . . when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely in your thoughts advanced to the state of Science . . ." -Lord Kelvin- Consider the array of sketches at: http://tinyurl.com/oxrwae7 . . . it would be exceedingly helpful to conduct three experiments to measure V1 (voltage across the bare-foot resistor/led array; V2 (voltage across incandescent lamp); V3 voltage across resistor/led array with anti- ghosting resistor added. >There's nothing wrong with any of the other LEDs. It's just the one >for the engine analyzer. The analyzer is allowing some current >through when it's off. With an incandescent bulb, this is not a >problem. With an LED, it is. Putting a 1k resistor solves the dimly >lit LED but it make the LED dimmer than the rest. So I'm trying to >solve two possible problems. 1) Keep the engine analyzer alarm LED >from being partially lit when it should be off, and 2) have the LED >at the same brightness as the other LEDs. > >Now it's possible (more like probable) that I'm going to have the >exact same problem with the Low Voltage warning since the LR3C >voltage regulator is designed for an incandescent bulb also. But I >haven't gotten to the point where I can start the engine so I don't know yet. Can't speak to internals of the engine analyzer but the LR3 regulator has a lamp output driver http://tinyurl.com/cgnwr5k INTENDED to exhibit some pull-down current on the lamp even when the LR-3 internal electronics are UN powered . . . The circuit above was suggested to soak off the effects of this small 'leakage' current that was insufficient to light an incandescent lamp but enough to tickle an LED into a small light output. I suspect a similar thing is happening with the engine analyzer. You can test the LV warn from the LR3 without running the engine. The light starts to flash as soon as you turn on the master switch even if the alternator is off and/or the engine is not running. Get those voltages and we can begin to sort out your current difficulty. Lord Kelven was also known to have said things like "I believe x-rays will prove to be a hoax" . . . and "There is nothing new to be discovered in physics now. All that remains is more and more precise measurement." These blunders by the venerable gentleman serve to remind us that the good student questions everything and seeks to sort un-substantiated opinion from demonstrable fact. Let us go to the workbench and demonstrate . . . Bob . . . ________________________________ Message 7 _____________________________________ Time: 11:21:54 AM PST US From: "Roger & Jean" Subject: Re: AeroElectric-List: Re: LED Ghosting > Does the LED have a series resistor? If so, what is its value? > Joe Yes. 390ohm (see attached).\ Perhaps you could use a zener with a voltage just slitely higher than the open circuit off voltage output. Put that in series with the LED, to block the small output, and reduce t he series resistor to bring the brightness up. Roger ________________________________ Message 8 _____________________________________ Time: 11:24:59 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: LED Ghosting > > > You can test the LV warn from the LR3 without running > the engine. The light starts to flash as soon as you > turn on the master switch even if the alternator is > off and/or the engine is not running. Stubbed my toe here . . . of course without the engine running, you'll have to boost bus voltage with an ac mains power supply to get the light to go out . . . hence, without that power supply you are correct, exercising the LR-3's lv warning is not yet possible. However, the LR-3 is intended to drive lamps with over 100 mA of operating current. So the schematic I suggested for one led MIGHT still be good for two but in any case, the configuration shown for the V3 measurement is good . . . the 1K resistor is simply reduced in value until the ghost-light goes out. So hooking your annunciator to the un-powered LR-3 should offer a platform for validating the value of the anti-ghosting resistor. Bob . . . ________________________________ Message 9 _____________________________________ Time: 12:07:45 PM PST US Subject: AeroElectric-List: Re: LED Ghosting From: "donjohnston" user9253 wrote: > I suggest that you put a 1.5k resistor across the LED per the engine analyzer people. Then replace the 390 ohm series resistor with a 330 ohm resistor. Or experiment with different values (all less than 390) to get the desired brightness. > Or put a pot in series with the dim LED and turn the pot until the current though the dim LED is equal to the current through one of the other LEDs. Then substitute a fixed resistor for the pot. > 40 years ago I could have calculated the resistor value. Now trial and error is easier. :-) > Joe I tried that. I ended up with no series resistor and it was still dimmer than the others. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=425032#425032 ________________________________ Message 10 ____________________________________ Time: 12:36:45 PM PST US From: rayj Subject: Re: AeroElectric-List: Re: LED Ghosting How about a brighter led, so it's dimmed level will be equal to the others. Raymond Julian Kettle River, MN The things we admire in men, kindness and generosity, openness, honesty, understanding and feeling are the concomitants of failure in our system. And those traits we detest, sharpness, greed, acquisitiveness, meanness, egotism and self-interest are the traits of success. And while men admire the quality of the first they love the produce of the second. -John Steinbeck, novelist, Nobel laureate (1902-1968) On 06/17/2014 02:06 PM, donjohnston wrote: > > > user9253 wrote: >> I suggest that you put a 1.5k resistor across the LED per the engine analyzer people. Then replace the 390 ohm series resistor with a 330 ohm resistor. Or experiment with different values (all less than 390) to get the desired brightness. >> Or put a pot in series with the dim LED and turn the pot until the current though the dim LED is equal to the current through one of the other LEDs. Then substitute a fixed resistor for the pot. >> 40 years ago I could have calculated the resistor value. Now trial and error is easier. :-) >> Joe > > > I tried that. I ended up with no series resistor and it was still dimmer than the others. > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=425032#425032 > > ________________________________ Message 11 ____________________________________ Time: 01:26:50 PM PST US From: Lyle Peterson Subject: Re: AeroElectric-List: Re: LED Ghosting I don't believe you will get satisfactory results with any combination of resistors. I think the only solution is a driver circuit between the output and the LED. A single transistor and a couple of resistors should do it. It may need a separate power source. On 6/17/2014 2:06 PM, donjohnston wrote: > > > user9253 wrote: >> I suggest that you put a 1.5k resistor across the LED per the engine analyzer people. Then replace the 390 ohm series resistor with a 330 ohm resistor. Or experiment with different values (all less than 390) to get the desired brightness. >> Or put a pot in series with the dim LED and turn the pot until the current though the dim LED is equal to the current through one of the other LEDs. Then substitute a fixed resistor for the pot. >> 40 years ago I could have calculated the resistor value. Now trial and error is easier. :-) >> Joe > > I tried that. I ended up with no series resistor and it was still dimmer than the others. > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=425032#425032 > > -- Lyle Sent from my Gateway E4610D desktop ________________________________ Message 12 ____________________________________ Time: 02:44:14 PM PST US Subject: AeroElectric-List: Re: LED Ghosting From: "donjohnston" nuckolls.bob(at)aeroelect wrote: > > Ooops, two LED's in series . . . should have asked about > that. Okay, I suggest we pay homage to our teachers one > of whom once opined: ". . . when you can measure what you are > speaking about, and express it in numbers, you know something > about it; but when you cannot measure it, when you cannot > express it in numbers, your knowledge is of a meagre and > unsatisfactory kind; it may be the beginning of knowledge, > but you have scarcely in your thoughts advanced to the state > of Science . . ." -Lord Kelvin- > > Consider the array of sketches at: > > http://tinyurl.com/oxrwae7 (http://tinyurl.com/oxrwae7) > I suggest we pay homage to our teachers one of whom once replied: "Dammit Bob, I'm a doctor, not a engineer" -Dr. Leonard McCoy- Unfortunately, this is a bit beyond my skillset. While the squiggly lines are not quite hieroglyphics to me, I'm not exactly sure what to do with them. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=425043#425043 ________________________________ Message 13 ____________________________________ Time: 04:29:37 PM PST US Subject: AeroElectric-List: Re: LED Ghosting From: "user9253" OK, here is another idea. Put a diode (1N4148 ?) in series with each of the bright LEDs. If you are lucky, the voltage drop across the 1N4148 will equal the voltage drop across the oil pressure solid state switch. Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=425054#425054 ------------------------------------------------------------------------------------- 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.