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LED Noise Filter

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cluros(at)gmail.com
Guest

Posted: Thu Sep 27, 2018 8:52 am Post subject: LED Noise Filter

As should have been expected, our ebay sourced PAR36 landing and taxi lights (4 in total) are producing varying levels of VHF noise. I see lots of old discussion about this on the list in 2013, but no products or diagrams for filters. I am planning on ordering the parts from digikey and making some filters unless there are some inexpensive filters available that are suitable for 18W LED lamps?Â 



The only circuit diagram I found online was

http://www.ptcaviation.com/wordpress/pi-filter/



Should I go with a simple 1 inductor 1 capacitor filter for each light or the more complicated version diagrammed above? Does it make any difference if we are planning on switching the power to 2 of the lights at 1 Hz?

Thank you,

Sebastien

kuffel(at)cyberport.net
Guest

Posted: Thu Sep 27, 2018 9:18 am Post subject: LED Noise Filter

Sebastien,

  

 <<  The only circuit diagram I  found online was 



 http://www.ptcaviation.com/wordpress/pi-filter/



 



 Should I go with a simple 1 inductor 1 capacitor filter for each light or  the more complicated version diagrammed above  >>

  

 The extra cost of the pi filter is so small I would just use them without  even trying a test of the simpler circuit.

  

 One really small correction on the above diagram.  C1 and C2 are  to filter high frequency noise while C3 is for lower frequencies.  The  leads from the LED to the first high frequency capacitor should be as short as  possible.  Therefore, the positions of C2 and C3 on the diagram should be  swapped.

  

 Tom Kuffel



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BARRY CHECK 6

Joined: 15 Mar 2011
Posts: 738

Posted: Fri Sep 28, 2018 6:32 pm Post subject: LED Noise Filter

Tom:

It is correct the way it is.

The 1000 uF Cap is a brute force filter.Â  It filters the DC of the battery.Â  The 1 uF and they may even be too big (I'm thinking .01 uF) are to filter the noise to ground from the component that is creating the noise...Â  The LED Light.

BTW, the 1 Hz noise...Â  You will NOT hear it.Â  Way below human ear range.

Barry

On Thu, Sep 27, 2018 at 1:23 PM The Kuffels <kuffel(at)cyberport.net (kuffel(at)cyberport.net)> wrote:



 	  Quote: 	
		         Sebastien,

 Â 

 <<Â Â The only circuit diagram I  found online was 



 http://www.ptcaviation.com/wordpress/pi-filter/



 



 Should I go with a simple 1 inductor 1 capacitor filter for each light or  the more complicated version diagrammed aboveÂ  >>

 Â 

 The extra cost of the pi filter is so small I would just use them without  even trying a test of the simpler circuit.

 Â 

 One reallyÂ small correction on the above diagram.Â  C1 and C2 are  to filter high frequency noise while C3 is for lower frequencies.Â  The  leads from the LED to the first high frequency capacitor should be as short as  possible.Â  Therefore, the positions of C2 and C3 on the diagram should be  swapped.

 Â 

 Tom Kuffel



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kuffel(at)cyberport.net
Guest

Posted: Fri Sep 28, 2018 8:20 pm Post subject: LED Noise Filter

Barry,

  

  <<  It is correct the way it  is.  >>

  

 My "small" change does not change the  schematic.  In both cases C2 & C3 are parallel and on the LED side of  the inductor.  From a noise suppression viewpoint believe people should be  aware that shorter leads are best for high frequencies.  In a severe case I  would consider soldering the high frequency capacitor at the LED  leads.

  

  <<  The 1  uF and they may even be too big (I'm thinking .01 uF) are to filter the noise to  ground from the component that is creating the noise...   >>



   

 Believe that is what I said.  Agree the 1 uF value seems  too high.  Personally would use no more than 0.1 uF and thought 0.01  uF would be the place to start.  But for all I know, the circuit designer  experimented and found this type of 1 uF capacitor to work best with this  LED.  So I limited my comment to the teaching point that the length of  leads carrying high frequency noise should be as short as  reasonable.

  

 Tom



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nuckolls.bob(at)aeroelect
Guest

Posted: Sat Sep 29, 2018 9:04 am Post subject: LED Noise Filter

At 11:19 PM 9/28/2018, you wrote:

  	  Quote: 	
		  ï»¿ 

 Barry,

  

  <<  It is correct the way it is.  >>

  

 My "small" change does not change the schematic.  In both cases C2 & C3 are parallel and on the LED side of the inductor.  From a noise suppression viewpoint believe people should be aware that shorter leads are best for high frequencies.  In a severe case I would consider soldering the high frequency capacitor at the LED leads. 	


  What is the nature of the noise being mitigated?

  Who is the victim? How does it manifest in operation

  of the victim?



  Noise comes in a constellation of flavors, sources,

  intensity and remedies. The filters I built for

  the LED fixtures were specific to an observed

  interference in the VHF Comm and VOR

  audio when the LED position lights powered with

  the constant current generators were turned on.



  Without knowing more details as to this

  particular recipe, any cut-n-try endeavors

  are simply experiments which may . . . or may

  not fix the observed problem.



  As a general rule, electrolytic capacitors

  are of no noise suppression value. Other

  reactive components (capacitors, inductors)

  need to be scaled for effective attenuation

  at the frequency(ies) of interest.



  For the purposes of this particular discussion,

  which of the ship's systems are complaining about

  operation of the LED assembly?



 

 

   Bob . . .

cluros(at)gmail.com
Guest

Posted: Sat Sep 29, 2018 12:53 pm Post subject: LED Noise Filter

VHF Radio. Basically background static. On some of the lights it's barely noticeable and you have to listen carefully to hear it, on at least one light it creates enough VHF noise to break squelch on the radio and creates a very noticeable amount of static.



On Sat, Sep 29, 2018, 10:08 Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:



 	  Quote: 	
		    At 11:19 PM 9/28/2018, you wrote:

  	  Quote: 	
		  Ã¯Â»Â¿ 

 	
Barry,

 Â 

 Â <<Â  It is correct the way it is.Â  >>

 Â 

 My "small" change does not change the schematic.Â  In both cases C2 & C3 are parallel and on the LED side of the inductor.Â  From a noise suppression viewpoint believe people should be aware that shorter leads are best for high frequencies.Â  In a severe case I would consider soldering the high frequency capacitor at the LED leads.

 Â What is the nature of the noise being mitigated?

 Â Who is the victim? How does it manifest in operation

 Â of the victim?



 Â Noise comes in a constellation of flavors, sources,

 Â intensity and remedies. The filters I built for

 Â the LED fixtures were specific to an observed

 Â interference in the VHF Comm and VOR

 Â audio when the LED position lights powered with

 Â the constant current generators were turned on.



 Â Without knowing more details as to this

 Â particular recipe, any cut-n-try endeavors

 Â are simply experiments which may . . . or may

 Â not fix the observed problem.



 Â As a general rule, electrolytic capacitors

 Â are of no noise suppression value. Other

 Â reactive components (capacitors, inductors)

 Â need to be scaled for effective attenuation

 Â at the frequency(ies) of interest.



 Â For the purposes of this particular discussion,

 Â which of the ship's systems are complaining about

 Â operation of the LED assembly?



 

 

 Â  Bob . . .

nuckolls.bob(at)aeroelect
Guest

Posted: Sat Sep 29, 2018 7:39 pm Post subject: LED Noise Filter

At 03:52 PM 9/29/2018, you wrote:

  	  Quote: 	
		  VHF Radio. Basically background static. On some of the lights it's barely noticeable and you have to listen carefully to hear it, on at least one light it creates enough VHF noise to break squelch on the radio and creates a very noticeable amount of static. 	


   Okay, and what is the LED product we're talking about?

   Have you had any conversation wthe the manufacturer?



 

 

   Bob . . .

cluros(at)gmail.com
Guest

Posted: Sat Sep 29, 2018 8:13 pm Post subject: LED Noise Filter

https://www.amazon.com/gp/product/B01KJ94Q1K/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1



If they were the +$300 ones made for aircraft I would call the manufacturer but these are 15% of the price of the aviation ones so I understand why the builder chose them. If we can fix this for $20 worth of parts it makes sense to me.

On Sat, Sep 29, 2018 at 8:43 PM Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:



 	  Quote: 	
		    At 03:52 PM 9/29/2018, you wrote:

  	  Quote: 	
		  VHF Radio. Basically background static. On some of the lights it's barely noticeable and you have to listen carefully to hear it, on at least one light it creates enough VHF noise to break squelch on the radio and creates a very noticeable amount of static. 	


 Â  Okay, and what is the LED product we're talking about?

 Â  Have you had any conversation wthe the manufacturer?



 

 

 Â  Bob . . .

wdaniell.longport(at)gmai
Guest

Posted: Sun Sep 30, 2018 3:31 am Post subject: LED Noise Filter

Having been through this one (cheap chinese landing light)...

I bought an USD20 light which completely blocked all comms within 20 feet.

I bought another one, American designed made in China for USD30 - and no noise at all.Â  I can dig out the manufacturer if youre interested.Â Â 

Will

William Daniell



LONGPORT

+57 310 295 0744

On Sun, Sep 30, 2018 at 12:16 AM Sebastien <cluros(at)gmail.com (cluros(at)gmail.com)> wrote:



 	  Quote: 	
		  https://www.amazon.com/gp/product/B01KJ94Q1K/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1



If they were the +$300 ones made for aircraft I would call the manufacturer but these are 15% of the price of the aviation ones so I understand why the builder chose them. If we can fix this for $20 worth of parts it makes sense to me.

On Sat, Sep 29, 2018 at 8:43 PM Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:



 	  Quote: 	
		    At 03:52 PM 9/29/2018, you wrote:

  	  Quote: 	
		  VHF Radio. Basically background static. On some of the lights it's barely noticeable and you have to listen carefully to hear it, on at least one light it creates enough VHF noise to break squelch on the radio and creates a very noticeable amount of static. 	


 Â  Okay, and what is the LED product we're talking about?

 Â  Have you had any conversation wthe the manufacturer?



 

 

 Â  Bob . . .

cluros(at)gmail.com
Guest

Posted: Sun Sep 30, 2018 5:57 am Post subject: LED Noise Filter

Certainly Will. We already have 2 batches of these trying to randomly find some that are better. No noise at all sounds ideal .



On Sun, Sep 30, 2018, 04:35 William Daniell <wdaniell.longport(at)gmail.com (wdaniell.longport(at)gmail.com)> wrote:



 	  Quote: 	
		  Having been through this one (cheap chinese landing light)...

I bought an USD20 light which completely blocked all comms within 20 feet.

I bought another one, American designed made in China for USD30 - and no noise at all.Â  I can dig out the manufacturer if youre interested.Â Â 

Will

William Daniell



LONGPORT

+57 310 295 0744

On Sun, Sep 30, 2018 at 12:16 AM Sebastien <cluros(at)gmail.com (cluros(at)gmail.com)> wrote:



 	  Quote: 	
		  https://www.amazon.com/gp/product/B01KJ94Q1K/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1



If they were the +$300 ones made for aircraft I would call the manufacturer but these are 15% of the price of the aviation ones so I understand why the builder chose them. If we can fix this for $20 worth of parts it makes sense to me.

On Sat, Sep 29, 2018 at 8:43 PM Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:



 	  Quote: 	
		    At 03:52 PM 9/29/2018, you wrote:

  	  Quote: 	
		  VHF Radio. Basically background static. On some of the lights it's barely noticeable and you have to listen carefully to hear it, on at least one light it creates enough VHF noise to break squelch on the radio and creates a very noticeable amount of static. 	


 Â  Okay, and what is the LED product we're talking about?

 Â  Have you had any conversation wthe the manufacturer?



 

 

 Â  Bob . . .

nuckolls.bob(at)aeroelect
Guest

Posted: Sun Sep 30, 2018 7:55 am Post subject: LED Noise Filter

At 11:12 PM 9/29/2018, you wrote:

  	  Quote: 	
		    https://www.amazon.com/gp/product/B01KJ94Q1K/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1 



 If they were the +$300 ones made for aircraft I would call the manufacturer but these are 15% of the price of the aviation ones so I understand why the builder chose them. If we can fix this for $20 worth of parts it makes sense to me. 	


   Sure . . . didn't know which product we're

   discussing . . . wanted to know if we

   were talking a COTS product or and

   entrepreneurial offering to the OBAM

   aircraft community.



   The components cited in the DIY article for

   filtering this device are problematic. Since

   our spectrum of interest is VHF, electrolytic

   capacitors are definitely contra-indicated.

   The inductor cited has some characteristics

   that are also problematic



 [img]cid:.0[/img]



   Since this is a 18w device powered by what

   has to be a constant current generator with the

   10 to 30v input range, current draw at 14

   volts can be estimated as (18w/14v)/0.8

   estimated efficiency equals 1.6 amps.



   While the 'rated' current for the device

   is 1.6A (meaning it won't burn up) the

   'saturation' value for the device is

   1.4 amps . . . meaning that its inductance

   goes to zero at or above 1.4A.



   I have no doubt that the design offered in

   the DIY article had some beneficial effects

   but it was not optimized for the task. There

   are dozens of more suited devices of this

   is one example:



  https://tinyurl.com/y8nrz56k



   Rated at 5A continuous, it has a nice

   impedance peak at 100 Mhz (our spectrum

   of interest). Now we want to team this

   with capacitors that are similarly

   suited to VHF energy management. A

   capacitor of 1000 picofarads has an

   impedance on the order of 1.6 ohms

   at 100 MHz. An exemplar component . . .

 

  https://tinyurl.com/yd3bh98e



   These are candidates for a noise abatement

   experiment.  Suggest the pi filter configuration

   with filter mount on shortest practical leads

   at the back of the lamp assembly. Since this

   device has a metal housing, suggest the black

   power lead be grounded to that housing along with

   the 'ground' leads of the two capacitors.



   It may well be that the noise problem is a

   combination of conducted and radiated so a

   power line filter may not completely tame the

   beast but this is a place to start. 



 



 



 

   Bob . . .

5bb84b7.jpg

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Filesize:

61.04 KB

Viewed:

7916 Time(s)

cluros(at)gmail.com
Guest

Posted: Sun Sep 30, 2018 10:07 am Post subject: LED Noise Filter

I was wondering about the radiated vs conducted thing but was thinking since it doesn't have any properties of an antenna any radiated noise must radiate from the wires. Further thought makes me realize this makes no sense since the lights are physically connected to a big metal wing and in any case no antenna is necessary to create a VHF signal that travels 15'.

Since we have 2 lights per wing, I'm planning on making a little box with short leads and a plug for each light. See diagram below.

Bob I'm unsure what you mean by the black power lead being grounded. Unfortunately the aircraft wiring does not include a ground wire to the forest of tabs ground bus behind the panel and simply grounds to the wing. I think you mean I should run a wire from each housing to a common ground point with the ground on my diagram. Is this correct?

[img]cid:ii_jmp6am4p1[/img]



On Sun, Sep 30, 2018, 09:00 Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:



 	  Quote: 	
		    At 11:12 PM 9/29/2018, you wrote:

  	  Quote: 	
		    https://www.amazon.com/gp/product/B01KJ94Q1K/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1 



 If they were the +$300 ones made for aircraft I would call the manufacturer but these are 15% of the price of the aviation ones so I understand why the builder chose them. If we can fix this for $20 worth of parts it makes sense to me. 	


 Â  Sure . . . didn't know which product we're

 Â  discussing . . . wanted to know if we

 Â  were talking a COTS product or and

 Â  entrepreneurial offering to the OBAM

 Â  aircraft community.



 Â  The components cited in the DIY article for

 Â  filtering this device are problematic. Since

 Â  our spectrum of interest is VHF, electrolytic

 Â  capacitors are definitely contra-indicated.

 Â  The inductor cited has some characteristics

 Â  that are also problematic



 



 Â  Since this is a 18w device powered by what

 Â  has to be a constant current generator with the

 Â  10 to 30v input range, current draw at 14

 Â  volts can be estimated as (18w/14v)/0.8

 Â  estimated efficiency equals 1.6 amps.



 Â  While the 'rated' current for the device

 Â  is 1.6A (meaning it won't burn up) the

 Â  'saturation' value for the device is

 Â  1.4 amps . . . meaning that its inductance

 Â  goes to zero at or above 1.4A.



 Â  I have no doubt that the design offered in

 Â  the DIY article had some beneficial effects

 Â  but it was not optimized for the task. There

 Â  are dozens of more suited devices of this

 Â  is one example:



  https://tinyurl.com/y8nrz56k



 Â  Rated at 5A continuous, it has a nice

 Â  impedance peak at 100 Mhz (our spectrum

 Â  of interest). Now we want to team this

 Â  with capacitors that are similarly

 Â  suited to VHF energy management. A

 Â  capacitor of 1000 picofarads has an

 Â  impedance on the order of 1.6 ohms

 Â  at 100 MHz. An exemplar component . . .

 

  https://tinyurl.com/yd3bh98e



 Â  These are candidates for a noise abatement

 Â  experiment.Â  Suggest the pi filter configuration

 Â  with filter mount on shortest practical leads

 Â  at the back of the lamp assembly. Since this

 Â  device has a metal housing, suggest the black

 Â  power lead be grounded to that housing along with

 Â  the 'ground' leads of the two capacitors.



 Â  It may well be that the noise problem is a

 Â  combination of conducted and radiated so a

 Â  power line filter may not completely tame the

 Â  beast but this is a place to start. 



 



 



 

 Â  Bob . . .

IMG_20180930_110009.jpg

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1.53 MB

Viewed:

7911 Time(s)

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Filesize:

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Viewed:

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echristley(at)att.net
Guest

Posted: Sun Sep 30, 2018 3:13 pm Post subject: LED Noise Filter

I've had excellent results using these devices.  N167EZ uses them for marker, strobe, taxi and landing lights.  I've inspected them with an oscilloscope.  Nothing but DC.  And, I've never heard radio inteference from them.   Especially of interest, I built the strobe by using an electronic  automotive turn signal flasher to alternate between two 30W supplies, that each drive an array of three 10W LEDs.  While testing them out in the sunlight, the easiest way to know they were working (a 601XL is hard to turn around and look back in) was to take my headset off and listen for the flasher's clacking.



http://www.mpja.com/LED-Driver-30W-Output-12-24VDC-Input/productinfo/31559+PS/

 

    On Sunday, September 30, 2018 9:58 AM, Sebastien <cluros(at)gmail.com> wrote:



  



 Certainly Will. We already have 2 batches of these trying to randomly find some that are better. No noise at all sounds ideal .On Sun, Sep 30, 2018, 04:35 William Daniell <wdaniell.longport(at)gmail.com (wdaniell.longport(at)gmail.com)> wrote:

 	  Quote: 	
		  Having been through this one (cheap chinese landing light)...

I bought an USD20 light which completely blocked all comms within 20 feet.

I bought another one, American designed made in China for USD30 - and no noise at all.  I can dig out the manufacturer if youre interested.  

Will

William Daniell

LONGPORT+57 310 295 0744





On Sun, Sep 30, 2018 at 12:16 AM Sebastien <cluros(at)gmail.com (cluros(at)gmail.com)> wrote:

 	  Quote: 	
		  https://www.amazon.com/gp/product/B01KJ94Q1K/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1



If they were the +$300 ones made for aircraft I would call the manufacturer but these are 15% of the price of the aviation ones so I understand why the builder chose them. If we can fix this for $20 worth of parts it makes sense to me.



On Sat, Sep 29, 2018 at 8:43 PM Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:

 	  Quote: 	
		    At 03:52 PM 9/29/2018, you wrote:  	  Quote: 	
		  VHF Radio. Basically background static. On some of the lights it's barely noticeable and you have to listen carefully to hear it, on at least one light it creates enough VHF noise to break squelch on the radio and creates a very noticeable amount of static. 	
   Okay, and what is the LED product we're talking about?   Have you had any conversation wthe the manufacturer?     Bob . . .

wdaniell.longport(at)gmai
Guest

Posted: Mon Oct 01, 2018 5:48 am Post subject: LED Noise Filter

for anyone that's interested this one worked for me.Â  I have all Dynon instruments and comms

Amazon:Â  "Abrams T3-W Led Grille Emergency Vehicle Warning Strobe Lights - White"



William Daniell



LONGPORT

+57 310 295 0744



On Sun, Sep 30, 2018 at 7:18 PM Ernest Christley <echristley(at)att.net (echristley(at)att.net)> wrote:



 	  Quote: 	
		  I've had excellent results using these devices.Â  N167EZ uses them for marker, strobe, taxi and landing lights.Â  I've inspected them with an oscilloscope.Â  Nothing but DC.Â  And, I've never heard radio inteference from them.Â Â  Especially of interest, I built the strobe by using an electronicÂ  automotive turn signal flasher to alternate between two 30W supplies, that each drive an array of three 10W LEDs.Â  While testing them out in the sunlight, the easiest way to know they were working (a 601XL is hard to turn around and look back in) was to take my headset off and listen for the flasher's clacking.



http://www.mpja.com/LED-Driver-30W-Output-12-24VDC-Input/productinfo/31559+PS/

 

    On Sunday, September 30, 2018 9:58 AM, Sebastien <cluros(at)gmail.com (cluros(at)gmail.com)> wrote:



  



 Certainly Will. We already have 2 batches of these trying to randomly find some that are better. No noise at all sounds ideal .On Sun, Sep 30, 2018, 04:35 William Daniell <wdaniell.longport(at)gmail.com (wdaniell.longport(at)gmail.com)> wrote:

 	  Quote: 	
		  Having been through this one (cheap chinese landing light)...

I bought an USD20 light which completely blocked all comms within 20 feet.

I bought another one, American designed made in China for USD30 - and no noise at all.Â  I can dig out the manufacturer if youre interested.Â Â 

Will

William Daniell

LONGPORT+57 310 295 0744





On Sun, Sep 30, 2018 at 12:16 AM Sebastien <cluros(at)gmail.com (cluros(at)gmail.com)> wrote:

 	  Quote: 	
		  https://www.amazon.com/gp/product/B01KJ94Q1K/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1



If they were the +$300 ones made for aircraft I would call the manufacturer but these are 15% of the price of the aviation ones so I understand why the builder chose them. If we can fix this for $20 worth of parts it makes sense to me.



On Sat, Sep 29, 2018 at 8:43 PM Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:

 	  Quote: 	
		    At 03:52 PM 9/29/2018, you wrote:  	  Quote: 	
		  VHF Radio. Basically background static. On some of the lights it's barely noticeable and you have to listen carefully to hear it, on at least one light it creates enough VHF noise to break squelch on the radio and creates a very noticeable amount of static. 	
 Â  Okay, and what is the LED product we're talking about? Â  Have you had any conversation wthe the manufacturer?   Â  Bob . . .

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