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iPad battery charger

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Remi Guerner

Joined: 14 Dec 2010
Posts: 284

Posted: Fri Jun 14, 2013 11:31 am Post subject: iPad battery charger

Hi All,

I have purchased a 12V battery charger for my iPad. This morning I flight tested it for the first time and was disappointed by the results:

1. The charger makes noise in the radio. The noise is  the same as when I push the squelch button. I made some more testing and found that the noise was there on any frequency below 126 MHz. No noise on any frequency above 126. Of course I checked that the noise disappears as soon as I unplug the charger from the cigarette lighter. 

2. The charging power is so low that it is just able to maintain the charging level of the battery, unless the iPad is turned off. 

Any suggestion or comments?

Regards

Remi Guerner

Duncan McFadyean

Joined: 18 Jan 2011
Posts: 219

Posted: Fri Jun 14, 2013 12:58 pm Post subject: iPad battery charger

The same thing happens with the 12v charger for a certain well renowned make

of handheld GPS!



Duncan McF.

Do not archive



--

craigb(at)onthenet.com.au
Guest

Posted: Fri Jun 14, 2013 3:36 pm Post subject: iPad battery charger

Perhaps you could use a Pulse Width Modulator. They run about $20 - $50 off

ebay, usefull for controlling voltage

And current you MAY be about to set the frequency high enough or low enough

frequency so you can't notice it on your comms

Or maybe you can find one of the "Old School" universal power packs that

just used resistors and diodes, so no switching

Noise, obviously you would need to do some cable "adjustments" or make a

short adaptor cable to make it fit the Ipad

One thing I have seen , was a USB adaptor for a "cigarette lighter" socket

and run it from USB power just a thought



Regards 

craig

klinefelter.kevin(at)gmai
Guest

Posted: Fri Jun 14, 2013 5:02 pm Post subject: iPad battery charger

I use a USB adapter for cigar lighter for my iPad, no noise.

Kevin



On Jun 14, 2013, at 4:35 PM, "craig" <craigb(at)onthenet.com.au> wrote:



 	  Quote: 	
		   

 

 Perhaps you could use a Pulse Width Modulator. They run about $20 - $50 off

 ebay, usefull for controlling voltage

 And current you MAY be about to set the frequency high enough or low enough

 frequency so you can't notice it on your comms

 Or maybe you can find one of the "Old School" universal power packs that

 just used resistors and diodes, so no switching

 Noise, obviously you would need to do some cable "adjustments" or make a

 short adaptor cable to make it fit the Ipad

 One thing I have seen , was a USB adaptor for a "cigarette lighter" socket

 and run it from USB power just a thought

 

 Regards 

 craig

rlborger(at)mac.com
Guest

Posted: Fri Jun 14, 2013 5:21 pm Post subject: iPad battery charger

Remi,



I installed a 12 volt power socket and put in a double USB adaptor.  One side for the iPad, the other for iPhone.  Works great, no noise.  Something like this:



http://www.amazon.com/Ultra-Compact-High-Output-Charger/dp/B00470C35E/ref=sr_1_10?ie=UTF8&qid=1371259137&sr=8-10&keywords=12+volt+usb+car+charger



There's a bunch of them available through Apple, Amazon, e-bay, etc.  And they're not expensive.



Blue skies & tailwinds,

Bob Borger

Europa XS Tri, Rotax 914, Airmaster C/S Prop.

Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP

3705 Lynchburg Dr.

Corinth, TX  76208-5331

Cel: 817-992-1117

rlborger(at)mac.com



On Jun 14, 2013, at 2:30 PM, Guerner Remi <air.guerner(at)orange.fr> wrote:






Hi All,

I have purchased a 12V battery charger for my iPad. This morning I flight tested it for the first time and was disappointed by the results:

1. The charger makes noise in the radio. The noise is  the same as when I push the squelch button. I made some more testing and found that the noise was there on any frequency below 126 MHz. No noise on any frequency above 126. Of course I checked that the noise disappears as soon as I unplug the charger from the cigarette lighter. 

2. The charging power is so low that it is just able to maintain the charging level of the battery, unless the iPad is turned off. 

Any suggestion or comments?

Regards

Remi Guerner

max8992

Joined: 28 Jul 2011
Posts: 142

Posted: Fri Jun 14, 2013 10:45 pm Post subject: iPad battery charger

Hi Remi (and all)

I don't like lighters so I bought (few years ago) a 4400 mAh hand-held battery which gives me an additional 6 hours of autonomy for my iPad. It's a 7 x 5 x 2 cm and 200 gr piece of plastic with a USB output and a mini USB input. 50€ or so. 

One of the main advantage is to be fully independent of the power of the ship.



Max  Cointe

mcointe(at)free.fr

F-PMLH Europa XS_TriGear

Kit #560-2003 912ULS/AirmasterAP332 450 hours



F-PLDJ Dyn’Aéro MCR 4S 

Kit #27-2002 912ULSFR/MTProp MTV7A 1550 heures

-----Message d'origine-----

De : owner-europa-list-server(at)matronics.com [mailto:owner-europa-list-server(at)matronics.com] De la part de Guerner Remi

Envoyé : vendredi 14 juin 2013 21:30

À : Europa-List Digest Server

Objet : iPad battery charger






Hi All,

I have purchased a 12V battery charger for my iPad.

_________________
Max8992
Europa XS #560 F-PMLH

frans(at)privatepilots.nl
Guest

Posted: Sat Jun 15, 2013 12:38 am Post subject: iPad battery charger

On 06/14/2013 09:30 PM, Guerner Remi wrote:

 	  Quote: 	
		   

 

 Hi All,

 I have purchased a 12V battery charger for my iPad. This morning I flight tested it for the first time and was disappointed by the results:

 1. The charger makes noise in the radio.


	


Basically this reveals that the charger is a piece of junk. Apparently

it was deemed too costly for the manufacturer to use some proper

shielding and filtering.



It may help to establish how the noise gets into the radio. What happens

if you disconnect the antenna plug? If the noise persists, the

interference enters the radio via the power supply or via direct

radiation into the radio. (The latter can be established by moving the

box closer or further away from the radio and see if it makes a

difference). If the noise disappears when you disconnect the antenna it

proves that the noise enters via the antenna (or antenna wire).



You can try to fix it yourself. Some things you can try:

1) Solder some capacitors directly between both input wires and both

output wires, as close to the box as possible. (I would open up the box

and solder the capacitors directly over the internal terminals).

Something about 6n8 (6.8 nanofarad) would be about right, it is not that

important.

2) Trim the in- and output wires as short as possible. (This is most

helpful if the noise enters the radio via the antenna).

3) If the device has a plastic housing, put it in a metal box. (This is

most helpful if the noise enters the radio via the antenna or by direct

radiation).

4) You can also wrap the input and output wires through a torroid,

similar to that as used for the VHF-antenna.



If these simple fixes don't give any improvement I would throw the box

away (or use it in the car or other place where it doesn't matter).



Frans

Rocketman

Joined: 07 Sep 2010
Posts: 87
Location: USA, Earth

Posted: Sat Jun 15, 2013 11:38 am Post subject: iPad battery charger

I've used the USB chargers for iPhone and iPad.  No comm noise...



Jeff - Baby Blue



On 6/14/2013 6:35 PM, craig wrote:

 	  Quote: 	
		   



 Perhaps you could use a Pulse Width Modulator. They run about $20 - $50 off

 ebay, usefull for controlling voltage

 And current you MAY be about to set the frequency high enough or low enough

 frequency so you can't notice it on your comms

 Or maybe you can find one of the "Old School" universal power packs that

 just used resistors and diodes, so no switching

 Noise, obviously you would need to do some cable "adjustments" or make a

 short adaptor cable to make it fit the Ipad

 One thing I have seen , was a USB adaptor for a "cigarette lighter" socket

 and run it from USB power just a thought



 Regards

 craig

Remi Guerner

Joined: 14 Dec 2010
Posts: 284

Posted: Sun Jun 16, 2013 11:52 am Post subject: Re: iPad battery charger

Frans, 

I have made some more investigations before reading your message. Here are the results:

1. Charging my iPad with my charger in another aircraft (Dyn Aero MCR 01): no noise. 

2. Charging my iPad with a friend's charger in my aircraft: same noise as with my own charger.

So it seems that the problem comes from the configuration of my panel and wiring: my cigar lighter is located very close to the Com radio while in the MCR is located very far on the passenger side.

3.   Charging my iPad with my charger in my aircraft:  at the same time I get the noise in the headset, the same noise is generated in a portable radio located at about 10 meters from the cockpit.

4.   Charging my iPad with my charger in my car: a portable radio placed close to the iPad or charger does not make noise.

This testing may allow you to better diagnose the cause of the problem. 

I will try with the antenna disconnected from the radio later on, as you suggested.    

Regards

Remi



[quote="frans(at)privatepilots.nl"]On 06/14/2013 09:30 PM, Guerner Remi wrote:

It may help to establish how the noise gets into the radio. What happens

if you disconnect the antenna plug? If the noise persists, the

interference enters the radio via the power supply or via direct

radiation into the radio. (The latter can be established by moving the

box closer or further away from the radio and see if it makes a

difference). If the noise disappears when you disconnect the antenna it

proves that the noise enters via the antenna (or antenna wire).

frans(at)privatepilots.nl
Guest

Posted: Mon Jun 17, 2013 1:17 am Post subject: iPad battery charger

On 06/16/2013 09:52 PM, Remi Guerner wrote:

 	  Quote: 	
		   

 

 Frans, 

 I have made some more investigations before reading your message. Here are the results:

 1. Charging my iPad with my charger in another aircraft (Dyn Aero MCR 01): no noise. 

 2. Charging my iPad with a friend's charger in my aircraft: same noise as with my own charger.

 So it seems that the problem comes from the configuration of my panel and wiring: my cigar lighter is located very close to the Com radio while in the MCR is located very far on the passenger side.


	


You see what some testing can reveal! Now it looks like it has something

to do with the wiring in your specific panel. Maybe the wiring has a

specific length which "resonates" at comm frequency and thus acts like

an antenna, or causing the oscillator in the charger to move its

frequency slightly so it ends up in the comm frequency band.



I'm now confident that you can solve the problem. Have you tried to

solder a capacitor over the two wires of the cigar lighter plug?

Or wrap the cigar lighter plug wires around a ferrite core (or better

yet, through a torroid?)

You may have noticed that today many cords of chargers and power

supplies have a thick cylinder inside the cord, most often close to the

device it is supposed to charge. Inside this cylinder there is such a

torroid and it is there just to avoid the problems you describe. So,

obtain such a cord from an old laptop power supply, trim it to length

(leaving the cylinder where it is) and use this cord to feed your cigar

lighter. I it also a good idea to use such a cord to feed your radio

(just make sure the wire diameter is up to spec).



Let's first try these simple solutions. I suspect that it will solve

your problem. Otherwise I know a few more but I don't think it will be

necessary.



Frans

rampil

Joined: 04 May 2007
Posts: 870

Posted: Mon Jun 17, 2013 10:10 am Post subject: Re: iPad battery charger

Essentially all modern DC-DC voltage converters and chargers are based on switching technology which uses a an RF range square wave generator to

shrink the size of inductors and capacitors.  These devices spray RFI

like nobody's business, especially if the harmonics don't reach the television

bands (where the FCC might actually care  )



Given the size of the connectors on an iPad, and the embedded surface mount stuff inside the connectors, I think adding bypass caps, even of 

the surface mount variety would be nearly impossible.  Easier to 

filter the Comm system and power line into the 12V "cigarette" connector.

_________________
Ira N224XS

Remi Guerner

Joined: 14 Dec 2010
Posts: 284

Posted: Mon Jun 17, 2013 10:27 pm Post subject: Re: iPad battery charger

Thank you Frans for your analysis and proposed fixes. Being too busy to work on that issue right now, I will do it this winter and will go back to the forum with the results.

Remi

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