So I was sitting at my desk and noticed this faint hissing. Turned off everything, shut down computer etc. Discovered it was the power supply for my P4Pro that is hissing while charging the battery? Does anyone else notice this?

Yes, it does that. Except that, it's also literally 'frying' when charging the battery. The battery itself stays pretty cool, but the charger is really burning. This happens just by having one battery (since I noticed the temperature level, I never dared to charge the RC at the same time with the battery).
Normal? Go figure...


I didn't bother investigating it more, as the charger is something cheap enought to risk having to replace at some point. (Unlike the gimbal for example, which I had to check really thoroughly).

betonven Posted at 2017-4-17 16:47
Yes, it does that. Except that, it's also literally 'frying' when charging the battery. The battery itself stays pretty cool, but the charger is really burning. This happens just by having one battery (since I noticed the temperature level, I never dared to charge the RC at the same time with the battery).
Normal? Go figure...

Hi Betonven, I always check the charger while charging (either a battery OR the RC, never at the same time), and I never noticed anything above slightly warm.  I suppose there is a transformer in the charger, and if it has a "loose core stack" the hissing may be due to the magnetic field alternately squeesing and releasing the lamels...  which could also increase the temperature.  

Antonio76 Posted at 2017-4-18 02:42
Hi Betonven, I always check the charger while charging (either a battery OR the RC, never at the same time), and I never noticed anything above slightly warm.  I suppose there is a transformer in the charger, and if it has a "loose core stack" the hissing may be due to the magnetic field alternately squeesing and releasing the lamels...  which could also increase the temperature.

Antonio, thanks for your input! So, apparently, this is indeed one more problem in my P4P (after a vibrating gimbal, a non-aligned camera and some shaky footage).

betonven Posted at 2017-4-18 06:45
Antonio, thanks for your input! So, apparently, this is indeed one more problem in my P4P (after a vibrating gimbal, a non-aligned camera and some shaky footage).

I'm very sorry for all your problems! Apparently there are some P4P that are plagued... Mine, sofar -and knock on wood- seems ok.

Antonio76 Posted at 2017-4-18 02:42
Hi Betonven, I always check the charger while charging (either a battery OR the RC, never at the same time), and I never noticed anything above slightly warm.  I suppose there is a transformer in the charger, and if it has a "loose core stack" the hissing may be due to the magnetic field alternately squeesing and releasing the lamels...  which could also increase the temperature.

Modern chargers/PSUs don't use transformers and don't have core stacks. They are all "switching power supplies".   The noise comes mainly from the ceramic capacitors busy doing their job.  Some cheap chargers that use low switching frequencies can be very noisy, decent ones are normally fairly quiet unless you put your ear to the box.  The Phantom one is processing a lot of power so it's not surprising that it can make a bit of noise, it is nothing to worry about.   I suspect there may be more than one manufacturer like with other bits of the P4 and that is the reason that some are more noisy than others, or maybe some use a different brand of ceramic capacitor.

Nigel_ Posted at 2017-4-18 08:14
Modern chargers/PSUs don't use transformers and don't have core stacks. They are all "switching power supplies".   The noise comes mainly from the ceramic capacitors busy doing their job.  Some cheap chargers that use low switching frequencies can be very noisy, decent ones are normally fairly quiet unless you put your ear to the box.  The Phantom one is processing a lot of power so it's not surprising that it can make a bit of noise, it is nothing to worry about.   I suspect there may be more than one manufacturer like with other bits of the P4 and that is the reason that some are more noisy than others, or maybe some use a different brand of ceramic capacitor.

Ah, good to know.... and it also shows how dated is my knowledge about electronics

Nigel_ Posted at 2017-4-18 08:14
Modern chargers/PSUs don't use transformers and don't have core stacks. They are all "switching power supplies".   The noise comes mainly from the ceramic capacitors busy doing their job.  Some cheap chargers that use low switching frequencies can be very noisy, decent ones are normally fairly quiet unless you put your ear to the box.  The Phantom one is processing a lot of power so it's not surprising that it can make a bit of noise, it is nothing to worry about.   I suspect there may be more than one manufacturer like with other bits of the P4 and that is the reason that some are more noisy than others, or maybe some use a different brand of ceramic capacitor.

That is very interesting information about the newer power supplies. Do you have some cross section photo or drawings showing these new devices?
I have to say that my power supply is very quiet and only gets warm unlike my Inspire 1 charger gets Hot...

Sorry about your troubles, I am on my #3 P4P
the first one had a noisy gimbal that vibrated, took it back to BB didn't even activate it!
second one worked fine for awhile and after awhile it was aiming to the left. I updated the FW and it seemed to fix it. now it is aiming to the left again (gimbal problem
My third one is working great so far.  I am disappointed with the QC or maybe just my bad luck?
Rich

RichJ53 Posted at 2017-4-18 10:14
That is very interesting information about the newer power supplies. Do you have some cross section photo or drawings showing these new devices?
I have to say that my power supply is very quiet and only gets warm unlike my Inspire 1 charger gets Hot...

No, it's not bad luck, it's just plain terrible quality control. I'm expecting my third one. Call me eccentric, but sorry, when I pay 1500$ for a semi-pro piece of equipment, I'm not looking the other way when I see problems. If the drone costed 150$, then I'd probably just learn to live with these, but not now.

RichJ53 Posted at 2017-4-18 10:14
Do you have some cross section photo or drawings showing these new devices?

A simple modern DC voltage converter/charger/power supply, as in the Phantom car charger, looks like this:


Main components from left to right:
electrolytic capacitor to ensure smooth input supply,
controller chip switches the power to the output on/off very fast, pulse width modulated to control the amount of power flowing through,
inductor to smooth the output (remove the spikes from the switching),
in blue - potentiometer to set the output voltage.
electrolytic capacitor to smooth the output (remove the dips).

The mains charger needs to deal with an AC supply so is a little more complicated but essentially it works the same way.  Also since it deals with 100W the components will be a little bigger than in that photo.

Could you clarify whether this happens right when you start charging the battery, or does it happen when it's been charging a battery or RC for a while?

RichJ53 Posted at 2017-4-18 10:14
That is very interesting information about the newer power supplies. Do you have some cross section photo or drawings showing these new devices?
I have to say that my power supply is very quiet and only gets warm unlike my Inspire 1 charger gets Hot...

DJI has treated me with awesome service and thoroughly love the products so far. The Inspire 1 and Mavic Pro are great...  You are correct that we expect the pro model to work correctly out of the box.  1.5K is a lot of money to spend and it is normal to want them to work the right way. They are made by humans and that means mistakes can happen. I hope others do not have as many problems with the P4P as I did. The new P4P is totally great and I have about 6 flights on it now. I am still learning the camera, the image just pops !  I never had any issues with my P3P or P4 .. they just worked right every time I went out to fly

Rich

Nigel_ Posted at 2017-4-18 10:57
A simple modern DC voltage converter/charger/power supply, as in the Phantom car charger, looks like this:
[view_image]

Thank you for the information, it really is very nice to see how this works!  

Thanks again for sharing
Rich