28V DC 'Cigarette lighter' sockets...

[Aucky]

Hi All, The R44 II DC 'cigarette lighter' socket is, as i'm sure you all know, a 28V socket, but many appliance chargers that me and my passengers would like to use/charge (video camera, iPhone/iPad etc...) all have input ranges of 12-14V or something similar. Infact the only things that seem to accept input ranges of 12-28V are aviation specific GPS units.

Are there any step-down splitters or the like that would reduce the voltage, and perhaps even double the outputs to 2 usable sockets? I have looked on google and maplin etc... but either that are hard to come by or I am searching using the wrong terms.... Surely there must be something to fit the bill...

Closest thing i could find is this Double Way Car Cigarette Lighter Adapter Splitter With Extension Cable From China Manufacturer, auto vehicle two manufacturer. but i assume that the output voltage would simply be the same as the input voltage, as opposed to stepping it down in any way...?

Thanks

[Jarvy]

Many big trucks in Europe use 24v, so there are available all sorts of accessories and voltage droppers at your nearest truck stop or internet store.

[lelebebbel]

I've had passengers plug their iPhone chargers into that 24V socket, to my surprise it worked. The chargers seem to be designed with truckers in mind it would seem.
If you are going to try it, do so on the ground... and at your own risk..

[mfriskel]

Call an avionics installer- it can be fairly easily and cheaply made into a 12v plug. 24v to 12v step-down transformer, you can look online.

[EN48]

24v to 12v step-down transformer

Hmmmm, last I heard transformers only work on AC power; the connector on the R44 would likley be 24V DC.

This may do the job: Voltage Converter (10 Amp) - Sporty's Pilot Shop

[Chi Sin Gei Si]

It's called an 'inverter'.

There are hundreds out there of varying quality. Suggest a modified sine-wave converter.

I use one on my boat...its about the size of an ipod (similar to the one below), steps down from my 28DCV system to a selectable AC output. Multiple connectors as option outputs. I have laptop connected to it through the charging socket, as well as cell phone via a USB output.



Here's another one.



Hope you find one.

(Not so sure I'd use one in the heli though. It gets quite hot sometimes.)

Google

[mfriskel]

"Hmmmm, last I heard transformers only work on AC power; the connector on the R44 would likley be 24V DC. "

I am not an electrical engineer, but do a search for 24v to 12v and you will find the term "stepdown transformer" and also "stepdown converter". The picture I attached actually was described as 24vdc to 12vdc stepdown transformer.
In helicopters that I have flown it looks like a brown bar connected to the "cigarette lighter" plug.

[Aucky]

EN48 - Thanks, thats exactly what I was looking for, but couldn't find

Chi Sin Gei Si - Thanks, but i'm not trying to turn in to AC, which is what the inverter would, as mfriskel said i'm trying to step down DC from 24v - 12v

mfriskel - Thats what I kept coming acorss, but wanted something rather less permanent to do the job that I could move between aircraft.

Thanks all, EN48 has hit the nail on the head

[HeliChopter]

mmmm........remind me to add "check for scorched carpet" to my checklist.

[mad_jock]

Speaking as a lorry driver I would be a bit canny with what ever you try and use as a "fix".

You can solid state voltage regulators which will take a a range of inputs voltages and output 12-14V.

Maplin> 12v voltage regulator

But a huge word of warning I have seen lorry electrics completely melted by what some fanny has plugged into the 28V socket.

[EN48]

EN48 has hit the nail on the head

You may find a better price by shopping around on the Web a bit.

[61 Lafite]

But a huge word of warning I have seen lorry electrics completely melted by what some fanny has plugged into the 28V socket.

This is undeniably true, but I can vouch for the effectiveness of the Aux Power Circuit Breaker in the R44 should you screw up your connectivity solutions!

[Aucky]

I noticed that the one that EN48 linked to was rated to 10A which is probably a little overkill. I was thinking about perhaps replacing the fuse with one rated at closer to 5A which will be ample for my needs and offer some extra protection. I'm not sure what amperage the aux circuit breaker is rated to without the manual.

There are lots of cheaper ones available at 24V to 12V for lorries, but with limited electrical knowledge, and the afformentioned fried circuits I'll happily pay the $60 with postage for the tried and tested 28V one. The reviewers seem happy. I don't see any problem with putting a simple splitter into this to turn it into 2 sockets...?

[EN48]

rated to 10A which is probably a little overkill.

Remember that 10 amps at 12 volts is only 120 watts - whether a lower current rating is OK will depend on what kind of device(s) you want to power. And the input side (24 volt) will see only about half the current (5 amps in the case of the unit I linked to).

I don't see any problem with putting a simple splitter into this to turn it into 2 sockets...?

Should be no problem as long as you dont exceed the power (current) rating for the voltage converter.

Not sure where you are located, but you may want to think about how you install this. In the U.S. the FAA would likely require a permanent install of the device to be approved by a FSDO, or at least a Form 337. If not attached permanently to the airframe, AFAIK, no documentation required. I often use industrial sterngth Velcro for devices like this to achieve a secure but "non-permanent" installation.

[Aucky]

EN48 - Your right, I hadn't considered the fact that at 12V you need a much greater amperage for the same wattage. I will see what amperage the aux power circuit breaker is rated at and go from there, but either way for the small devices i would like to charge/operate on longer trips 10A would no doubt be sufficient. With regards to installation, i'm in the uk, and not considering this as a permanent attachment, rather a portable plug in accessory in itself... I will test to see how hot the unit gets and decided what precautions will be necessary to ensure that it doesn't cause damage wherever I choose to locate it. I'm sure the documentation associated with the unit will suggest certain precautions. Thanks

[500e]

((( Wallen Antennae ))) We Design and Manufacture Quality Antenna Systems to meet High Performance Requirements
NEW IP65 rated waterproof converters. If you require converters for harsh environments, have a look at our new ruggedised versions: - Alfatronix Ltd
Both these Co make 24\12 volt droppers with fail safe \ overload protection & the guarantee is for life!! have alfatronix changed after 10 years by return of post.
We use both these makes with a very low fail rate ( under .2 %)
Not the cheapest but commercial quality products, you know it makes sense.
Both makes have click in holders

[Gaseous]

I've had passengers plug their iPhone chargers into that 24V socket, to my surprise it worked.

Hmm. Lots of these small chargers use 78xx or LM3xx voltage regulator technology which will be OK up to 35 volt input and so will work. Other internal components such as capacitors may well only be rated at 16 volts if designed for 12v.

On 24v they could survive the overvoltage or they may go bang.

The problem is one cannot tell whats in it and if it is OK to use. Just 'cos it works doesn't make it safe. I don't have a 24 volt socket, but if I did I would not allow anything in it without a regulator as described in the above posts unless it says on it, suitable for 24v systems. The prospect of smoke and bangs in the air? - even little ones. No thanks.

[Tailboom]

I charge my I Phone all the time in the socket on the 44, Ive never had a problem !
I've used it often with my I Phone 3 + 4, also a Nokia E51 and a I Pod.

[spinwing]

Mmmmm ......

GO HERE ...

Jaycar Electronics - Search results

... and scroll down the page a bit you will find 2 choices one that has 12v DC 1.1 Amp output and another that has a 12v DC 3 Amp output .... all you will have to do is put them in a suitable container etc !!!

These seem to be made in Germany so should be available in europe!

Good luck ....

[Tarman]

You could always switch the phone off whilst you are flying and charge it when you land !

I wouldn't take a chance that a phone or something else not essential for flight my be slowly damaging itself or maybe the wiring in the helicopter while I'm blissfully unaware in the front.