Electronics gurus - hacking the car charger?

[idiogenic]

Hmmm so maybe if I configure the Drok step up regulator correctly I don't need this chip then?

Also, if it can take a 12v input and output 13v, why the hell doesn't it work at 12.2v?

And what does the larger black box do?

 

[Cyberpower678]

Hmmm so maybe if I configure the Drok step up regulator correctly I don't need this chip then?

Also, if it can take a 12v input and output 13v, why the **** doesn't it work at 12.2v?

And what does the larger black box do?

The larger box is the power transformer. The chip is just a cutoff circuit if input doesn't meet requirement. The actual power conversion is done in the box, which has the transformer.

 

[Robbyg]

The other chip obviously is a Toshiba TPHR8504PL

Obviously
I have no idea how you read the other numbers, you must have pulled yours apart. From the picture provided all I can make out is PHR850

Rob

 

[Robbyg]

That's is a basic voltatage regulator with thermal overload. It will input a voltatage from 12 to 26 volts and output a steady 13 volts.

Sent from my SM-G900I using MavicPilots mobile app

No, No that's not what it's doing.

 

[Egika]

Obviously
I have no idea how you read the other numbers, you must have pulled yours apart. From the picture provided all I can make out is PHR850

Rob

No need to take anything apart. It's just experience with electronics.

 

[fRebbles]

Why not wire the output of the DROK into a 12V socket, then just plug the DJI charger into it?. It'll then be useful for other picky charging circuits in future.

Attached is a simple adaptor I used at home. Can pick these up at places like jaycar or eBay.

 

[idiogenic]

Yeah that's what I'll end up doing. Was just hoping to streamline the whole system a bit but it looks like the components inside the cigarette plug are required.

 

[idiogenic]

So I set the output of the Drok transformer to 14.5 volts and directly wired the DJI charger in as per the photo (the chip from inside the cigarette plug is in the black heatshrink), doesn't bloody work though!

It looks like it starts charging, i.e the sequential flashing lights on the battery start doing their thing, but only 3 or four times, and then they stop doing the sequential flash and stay solid green.

Anyone have any ideas why that might be the case?

(NB - voltage is stable under load, doesn't appear to drop, the Drok transformer does have a current regulating adjustment, have adjusted it both ways and doesn't seem to make a difference)

 

[idiogenic]

Ok, got it working. Hadn't adjusted the current output screw properly (there's no documentation supplied with the Drok transformer, which is a bit crap).

Output is stable at 14.0V, down to an input of 11.95V. Charges easily now.

Still, shouldn't have to go to this much effort just to get a product to work as advertised.

 

[Darmie]

I'm wondering if this unit has a step up voltage circuit

DJI Mavic Pro - Car Charger

 

[AVsupport]

Did you remove the thermal protection in the cigarette lighter part ..?

 

[marin849]

By changing one of the resistors (or soldering another in parallell) we should be able to change the "low voltage cutout" voltage.
In the datasheet for AP4310 there is an internal reference level of 2,5V, so we should be looking at two resistors between battery + and -, that gives about 2,5V when then voltage is about 12,x v. The ratio of the two resistors will be appr. 1:4.

(Then if the actual charger does not contain a buck-boost converter it will not fully charge the battery anyway...)