24->12V dropper failing?

[vas]

hi,

boat is 24V, there's an oldish 24-12V 20A dropper (or may be 10A, don't really remember) above the batteries feeding:

N2K network with 4GMI10s, a VHF, a sony radioCD, a fusion sub and the domotic system that's running the led lighting around plus a couple more tiny consumptions.

Now, let's just say that the thing is not really stable...
With 8 1W LEDs, one GMI10 (on the voltage screen to check values) and the radio running, once every 10-20mins, current would dive to 7-9V, domotic would reset, radio playup and a few seconds later, everything would be back to normal.

It's relatively safe (and cheap!) bet to blame the dropper and go shopping for a new one.

First Q, any reason not to agree with that? anything I may be missing? Mind it did it last year as well but I blamed it to my stupidity of connecting the fridge to 12V instead of 24, but now it's properly on 24V (and off anyway!)

Second Q, any recommendations on what to buy? My mates here say, just buy one from the local el. shop. On ebay I can get a 20A one from 20euro or a better quality (seemingly) 30A for almost 200euro. Any pointers?

I could temporarily wire the 12V to the one service battery, open up the dropper and check condition of capacitors (that's what usually fails after time and at the extreme heat of the e/r) but I don't know if I should be bothered tbh...

Any other ideas?

cheers

V.

 

[MapisM]

domotic would reset

I believe you are right in blaming the dropper V, but sorry, I don't have any good model/brand to suggest.

Otoh, your sentence above indeed made me smile.
I don't think there are other boats on this planet of similar vintage with such a first world problem...!

 

[vas]

I believe you are right in blaming the dropper V, but sorry, I don't have any good model/brand to suggest.

Otoh, your sentence above indeed made me smile.
I don't think there are other boats on this planet of similar vintage with such a first world problem...!

P,

I thought the speciality of this forum is indeed first world problems, else I'd post in PBO

Thinking about it, maybe going straight from a dropper to various consumptions some of which are apparently sensitive to voltage drop is not such a good idea. Maybe I should install a small sealed UPS battery and a 24V->12V CHARGER for it and pick up all my loads out of the balanced and stabilised battery, anyone done that?
If it's possible or indeed reasonable JFM should have done it in Match but I don't remember such a discussion
One more reason why we desperately need a new built thread John!

cheers

V.

 

[Anders_P42]

These are good, but be aware the actual output is 13.6V not 12V

http://alfatronix.com/products/view/2

 

[vas]

These are good, but be aware the actual output is 13.6V not 12V

http://alfatronix.com/products/view/2

thanks, should probably get a 30A or even a 50A non-isolated one. Good thing I bought a decent DC amp clamp so I can check loads today and decide.

Regarding output, I'm pretty sure the one installed now is 13.something (little) (at least the GMI shows 13V)

cheers

V.

 

[Anders_P42]

thanks, should probably get a 30A or even a 50A non-isolated one. Good thing I bought a decent DC amp clamp so I can check loads today and decide.

Regarding output, I'm pretty sure the one installed now is 13.something (little) (at least the GMI shows 13V)

cheers

V.

Two options there, 24A continuous rated or 50A. That 50A one does look a nice piece of kit.

 

[jrudge]

Alfatronics are oem in Fairline ( or at least they are on mine !)

 

[Hurricane]

Alfatronics are oem in Fairline ( or at least they are on mine !)

Likewise on our Princess.
Lots of them were fitted in the factory so I used an Alphatronics to drive one of my additional audio systems.
Alphatronics seems to be the quality option.

 

[MapisM]

Alfatronics are oem in Fairline ( or at least they are on mine !)

Likewise on our Princess.
Lots of them were fitted in the factory so I used an Alphatronics to drive one of my additional audio systems.
Alphatronics seems to be the quality option.

Hang on folks, that name rang a bell!
Is actually "Alfatronix" the correct spelling of what you are talking about, by chance (see below)?
I've got several of these boxes behind the scenes in the DP, wherever 12V is required.
Zero experience yet about how good/reliable they are, but if that's the one, I'm glad to hear what you're saying! :encouragement:

 

[jrudge]

Yes just mine are rectangular 30a versions. I have 3 that I have found so far

 

[MapisM]

Yup, some are larger also in my boat, though I can't remember the power.
I had a pic of just the one above, which IIRC is dedicated to the car radio in one of the guest cabins.

 

[Hurricane]

Hang on folks, that name rang a bell!
Is actually "Alfatronix" the correct spelling of what you are talking about, by chance (see below)?
I've got several of these boxes behind the scenes in the DP, wherever 12V is required.
Zero experience yet about how good/reliable they are, but if that's the one, I'm glad to hear what you're saying! :encouragement:

Yep - thats the one.
As usual, it takes an Italian to correct us on spelling!!!

I don't know of any that have failed so, IMO, you have the best that is available.

 

[markc]

So, I have 3 instruments on the flybridge that are not working. I did have the chance to take one out and there was no supply reaching the unit. Is there the likelihood that I have a couple of local droppers under the FB helm and one isn't working?... this 24v stuff is all new to me!

 

[vas]

first of all thanks all for the suggestion,

seems that I'll go for a Cactus Alfatronix PV24S - it's under the psychological mark of 100quid (with the added bonus that your quid is not doing too well after the elections )
Tried to calculate consumption, pretty sure I'm missing a few:

ALL led lights on, in out the lot is just under 6A (.2A each power led), say 6.5A with the rest of the domotic, GSM module and a dozen presence sensors.
Fusion sub probably not more than 8A when trying to rip your eardrums (or rather intestines) off, Sony radioCD another few Amps
NMEA2K with four small 4inch gauges, doh, forgot to check but v.little even with the N2K triducer and gps mushroom
Garmin VHF200 around 2A (anyone can give me a reason the VHFs are NOT 24V please???)

Cannot think that at full peak it's going to reach 25A.
Mind all the charging in the cabins and elsewhere for portable devices is from dedicated (per socket!) 1 or 2A 24->5V droppers, so wont count them in this.

Yes, it would be safer to get the 50A big thing but cannot even find it in ebay (let alone wouldn't be happy with the price!)
If it turns out being insufficient, I'll isolate the stereo and either use the old one (if it's up to it, or get a dedicated dropper)

So, I have 3 instruments on the flybridge that are not working. I did have the chance to take one out and there was no supply reaching the unit. Is there the likelihood that I have a couple of local droppers under the FB helm and one isn't working?... this 24v stuff is all new to me!

what are the instruments? and are they 12V for sure? Few nav related gear are either or autoswitching, makes life a bit more difficult.
I'd check for a fuse first before going into ripping things off hoping to find a failed dropper (that generally don't fail...)

cheers

V.

 

[MapisM]

So, I have 3 instruments on the flybridge that are not working. I did have the chance to take one out and there was no supply reaching the unit. Is there the likelihood that I have a couple of local droppers under the FB helm and one isn't working?... this 24v stuff is all new to me!

I never went as far as checking instruments installation on any F165/175, so I can't confirm the likelihood, but possible it is for good.
It also depends on the instruments, though - as Vas already pointed out: IF they accept both 12 and 24V, it would be a nonsense to install a dropper.
For instance, most Furuno stuff (also of your boat vintage) is multivoltage, but not all.

 

[MapisM]

ALL led lights on, in out the lot is just under 6A

V, why are you including the lights in the 12V system?
Most bulb types are available in 24V (they can usually accept from 10 to 30V DC), and even for those which aren't, you can use the trick of connecting them coupled in series.
In my DP, most lights were already connected that way to use 12V halogen bulbs without any droppers, which was the original installation.
I replaced them all with LED GU5.3 12V bulbs - btw, before doing that I posted asking views on LED bulbs connected in series - and they are now working perfectly. :encouragement:

 

[MapisM]

As usual, it takes an Italian to correct us on spelling!!!

LOL, I had good teachers here in the asylum!

I didn't mean to blame you anyway, and neither jrudge, of course.
It just popped to my mind that the exact name of the thing might be handy for Vas...

 

[vas]

V, why are you including the lights in the 12V system?
Most bulb types are available in 24V (they can usually accept from 10 to 30V DC), and even for those which aren't, you can use the trick of connecting them coupled in series.
In my DP, most lights were already connected that way to use 12V halogen bulbs without any droppers, which was the original installation.
I replaced them all with LED GU5.3 12V bulbs - btw, before doing that I posted asking views on LED bulbs connected in series - and they are now working perfectly. :encouragement:

P,

the FYES domotic system I'm using, when installed on a house, has a power supply that feeds it with 15V. Designer explained, that all work from 12-16V, but not going to be happy with 24-28V. The dimmable Leds are part of the system, so they do need that voltage as well. Not a big issue, at home on a main power loss, I can have a much larger system running (IC, sensors, GSM, etc) for at least 20h on a 18Ah 12V sealed battery (standard as system backup-hence me thinking of doing that in MiToS as well)

Anyway, will hook the 12V devices on one of the service batteries (the one I use to fire up the genny...) and check that everything works before ordering the new dropper

cheers

V.