12V DC to 14V DC adapter - Do they exist?

Richard10002

Richard10002

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I have a nice Samsung 22" TV at home which we don't really use and I noticed that the AC adapter provides 14 V via one of the usual barrel type connectors.

It would be really nice to have it on the boat, but I've searched high and low, and can't find a 12V to 14V adapter. I actually have an adapter that has a regualated variable output, but its range is from 15V to 24V. I use it for laptop and netbook set at 19V.

Am I missing something, or do adapters with a 14V output not exist?

Would it harm the TV if I fed it with 15V, or would there be some kind of leeway, or protection, built in?

Help.

Richard
 
Have you tried feeding it with the boat's 12v directly? That would usually actually be closer to 13v with well charged batteries, or 14v when charging, so it might well work without adapters. Do fuse the supply though.
 
You stand a good chance it will work fine directly from 12v.

I have a Samsung monitor that I picked because the same model is sold with 12v brick in some countries and a 14v brick in others. Mine had the 14v brick and runs fine directly from the boat supply.
 
I take it you were measuring the voltage output without any load on the AC adapter. Some appliance specific adapters are not very well regulated and the output voltage could drop to close to 12v once load is applied to the adapter.

It will not harm the TV is plugged directly into 12VDC so I would try it and see.

I have a telefunken 12VDC and I had a faulty cable one time that measured 12VDC with no load but once the TV was plugged in the voltage dropped to 10VDC and the TV would not work correctly. Once the faulty cable was rectified the TV worked perfectly.
 
noelex said:
You stand a good chance it will work fine directly from 12v.

I have a Samsung monitor that I picked because the same model is sold with 12v brick in some countries and a 14v brick in others. Mine had the 14v brick and runs fine directly from the boat supply.
Click to expand...

How did you find out that your monitor is sold with 12V in some countries, and 14V in others? Presumably deep in a Samsung website somewhere?
 
Marlin said:
Have you tried feeding it with the boat's 12v directly? That would usually actually be closer to 13v with well charged batteries, or 14v when charging, so it might well work without adapters. Do fuse the supply though.
Click to expand...

Thanks to all for the usual quick replies!

I haven't tried it with 12V yet 'cause it's at home. I'll probably bring it to the boat tomorrow and give it a try.
 
Richard10002 said:
Would it harm the TV if I fed it with 15V, or would there be some kind of leeway, or protection, built in?
Click to expand...

It would probably be OK but there's no point in risking it.
If you fed the 15 volt supply through one or two diodes you would drop the supply down to the right voltage. It would only cost pence to do.
 
Richard10002 said:
How did you find out that your monitor is sold with 12V in some countries, and 14V in others? Presumably deep in a Samsung website somewhere?
Click to expand...
Yep google is your friend.
Usually the straight 12v models are fine on a boat supply, but 14v models are generally safer as under voltage rarely causes any damage.
Most 14v models will run fine on 12v. That my monitor was sold with both a 12 and 14v supply confirmed that the power supply was versatile.

Measuring the actual voltage of the AC brick can be helpful. If the designed power supply is poorly regulated and measures a high voltage with no load you can be confident it has been designed for at least transient higher voltages.
 
Measuring the actual voltage / current of a wall-cube (brick) when actually connected to its device is always a pain. Worth making up a lead specifically to do the job which can be inserted between cube and appliance. (The 'power tips' which plug into the device are easy to come but the 'sockets' are harder to find and you may have to improvise).
 
VicMallows said:
Measuring the actual voltage / current of a wall-cube (brick) when actually connected to its device is always a pain. Worth making up a lead specifically to do the job which can be inserted between cube and appliance.
Click to expand...

It is worth making this measurement, but the unloaded voltage is often more telling and is easier to measure.
If the unloaded voltage is high the electronics will be subject to this voltage (very briefly) when connected.
There are no guarantees, but if the brick is poorly regulated, with high voltages at zero current, the circuitry has usually been designed to be more tolerant of a slight over voltage over a longer period.
 
External power supplies for TVs etc these days are mainly switch mode power supplies. These are regulated and will deliver the labeled voltage at no load or full load. The old type with a transformer are best identified by being heavy. They do have usually poor regulation characteristics. ie higher voltage with no load falling with load.
Most electronic devices need a regulated supply internally. So if they have a supply with poor regulation they need an internal regulator. therefor will likely run happily on a widely varying voltage supply. Those normally using a switch mode type regulated supply might only expect a well regulated supply. Of course we can only speculate.
As said you could use the 15v supply with a silicon diode in series which will drop .7 or more volts.
Or just try it on ships 12v supply. good luck olewill
 
Got it on board but the 12V and 15V plugs didn't fit, so I plugged it into a 300W inverter and it didn't seem to draw too much power, so all was fine. Except that the TV is 24" rather than 22", and a bit too big....

So I took it home, and bought one of these, (I've had my eye on it for a while :) ):

http://www.currys.co.uk/gbuk/tv-dvd...g-ue22f5410-smart-22-led-tv-21322573-pdt.html

Pretty much the dogs danglies in boat Tv terms - connected to the mobiles wifi hotspot, it does all kinds of stuff, including catchup TV, and an actual full web browser, (it's a bit clunky, but works fine).

So everything in the TV garden is rosy.

Thanks for all the info - still looking for a way of supplying the power DC to DC, as I don't like inverting unnecessarily. I'm guessing that 12V to 14 V will be a better conversion than 12V to 240V to 14V.
 
While your tv probably will work on 12v a boats '12v' power supply is a dirty supply. With relays, solenoids and a nice fat alternator in the mix you may occasionally see very high spikes on the supply that a device not designed for direct connection to such a supply might take offese at.

Some sort of filter might be a good idea or install a dc /dc converter to isolate your tv from the dirty stuff.
 
Richard10002 said:
So I took it home, and bought one of these, (I've had my eye on it for a while :) ):

http://www.currys.co.uk/gbuk/tv-dvd...g-ue22f5410-smart-22-led-tv-21322573-pdt.html

Pretty much the dogs danglies in boat Tv terms - connected to the mobiles wifi hotspot, it does all kinds of stuff, including catchup TV, and an actual full web browser, (it's a bit clunky, but works fine).

So everything in the TV garden is rosy.

Thanks for all the info - still looking for a way of supplying the power DC to DC, as I don't like inverting unnecessarily. I'm guessing that 12V to 14 V will be a better conversion than 12V to 240V to 14V.
Click to expand...

I'm looking at getting one of these for my boat, I've been looking for a 12v to 14v transformer/stabilizer/regulator. have you found one that suites your needs?
 
Richard10002 said:
So I took it home, and bought one of these, (I've had my eye on it for a while :) ):

http://www.currys.co.uk/gbuk/tv-dvd...g-ue22f5410-smart-22-led-tv-21322573-pdt.html

Pretty much the dogs danglies in boat Tv terms - connected to the mobiles wifi hotspot, it does all kinds of stuff, including catchup TV, and an actual full web browser, (it's a bit clunky, but works fine).

So everything in the TV garden is rosy.

Thanks for all the info - still looking for a way of supplying the power DC to DC, as I don't like inverting unnecessarily. I'm guessing that 12V to 14 V will be a better conversion than 12V to 240V to 14V.
Click to expand...

I've been looking at getting one of these for my boat and like you I don't want to invert to 230V then back down to 14V. I have found a couple of possibilities of 12V cigarette connections to 14V but was wondering if you have managed to try it directly on 12V or found an adapter you are happy with?

swmenzies
 
swmenzies said:
I've been looking at getting one of these for my boat and like you I don't want to invert to 230V then back down to 14V. I have found a couple of possibilities of 12V cigarette connections to 14V but was wondering if you have managed to try it directly on 12V or found an adapter you are happy with?

swmenzies
Click to expand...

I'm using it via the 240V provided by a 300W inverter. Doesn't seem efficient in terms of power usage, but it works fine.
 
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