Run TV without inverter?

Allan12210 · Jun 19, 2014

I built my own DC-DC converter (which only cost me 5x what this one costs). The concept is very good....highly efficient. Check out this link:

http://www.powerstream.com/dc-2171.htm

Make sure the amp draw or power delivery is matched to your TV.

I use my dc-dc converter to provide a constant 19V output for my laptop. I already have a SuperSonic LED 12V TV (with built in DVD, available on Amazon) that handles the voltage range you would expect. They're used in RVs so it would not be unlike what it would see in the boat. Usually a 12V appliance will run at +/- 10% Voltage, but no guarantees from me.

Benny17441 · Jun 20, 2014

Boat 12V circuitry is subject to voltage variations. Make sure your TV can operate within a reasonable voltage range. Check to see if your brand and model have any circuitry protection against large fluctuations. I would recommend the use of a converter.

Rich Stidger · Jun 20, 2014

I have a Skyworth 19" LED TV that runs just fine on the ship's 12V. This TV is marketed to the trucking and RV industry. Before that I had a Coby 15" (total POS) that also ran fine on ship's power.

Of course, YMMV.

Chief RA · Jun 20, 2014

To answer your question I need to get you to measure the voltage going into your TV. If it is 12v as I suspect, then yes, you will be able to connect it to your battery system. I use a 12dc TV also. Chief FCC lic#1890

Don S/V ILLusion · Jun 20, 2014

Unless the TV you choose is designed to accept voltage spikes, a converter/line maintainer is essential. Simply using any off the shelf TV direct connection to the boat's system will eventually destroy the input circuit. Benny and Rich gave you some good advice. Any number of things can cause spikes you won't see by simply measuring voltage on any instantaneous basis.

Chief RA · Jun 20, 2014

Don: don't overreact to what he asked. All he is asking about is a TV! If I don't think its a problem then it probably isn't. I have used direct DC as a power source for my TV and laptop for years and they work fine plus my laptop is 5 yrs old! My profession and extensive education, certifications was/is electronics, not my hobby. Chief

weinie · Jun 20, 2014

I've been running an XM radio like this by replacing the AC adapter with a cigarette lighter adapter with no step down in voltage. But of course, the radio is designed to use 8 x 1.5 D batteries.

Don S/V ILLusion · Jun 20, 2014

Chief RA said:
Don: don't overreact to what he asked. All he is asking about is a TV! If I don't think its a problem then it probably isn't.

Opinions vary. I was expressing mine after having make that mistake several times before I realized I was blowing power input boards. It happens.

nolasafari · Jun 20, 2014

I didn't read all the post above so have no clue as to what they said. I purchaded a Elements 19" HD TV at Walmart ($98.00) which had a power brick that outpiuts 12 volts. Went home looked thru my box of 12 volt power port connecters and found one that fit, went to the boat a plugged it in. I have not used the power brick with it yet. Has been working for a month with no problems. YMMV.

I did buy the extended 2 year warranty for 8 bucks.

Maine Sail · Jun 21, 2014

scherzoja said:
Thanks for the advice. I think I'll be on the safe side and get a dc to dc converter just in case my TV can't handle the voltage ranges on the boat's DC system. It's only about $25 and that seems safer than potentially damaging a $150 TV.

Now, I just have to figure out how to train my wife to turn the power off before falling asleep!!!
I should have bought the TV with a timer.

Thanks again for everyone's help.

Some companies cheap out on the input and the TV or laptop can only accept a well controlled XX volts... Sometimes a call to the engineering department of the manufacturer can help. Both myself and Roger Long owned computers that needed 12V not 12.5+. The laptop maker confirmed that it would only accept 12V and thus needed a DC to DC converter to work correctly. On the other side I had a TV that could accept 11V to 15V.... I was able to confirm this with the manufacturer...

A converter is a wise approach if you are unable yo get an answer from the manufacturer...

Chief RA · Jun 21, 2014

DC to DC controller for computer, yes. Chief

skeet · Jun 23, 2014

Yeah, get off the inverter if you can.
Simple and actually cost effective thing is this:
http://www.amazon.com/Naxa-Volt-Widescreen-Player-Remote/dp/B002C47JBA/ref=cm_cr_pr_product_top

or pick one up at a TA truck stop (150 bucks last I checked).

This actually pulls in quite a few channels and I mounted it inside:
http://www.amazon.com/RCA-ANT702F-D...8&qid=1403531586&sr=1-11&keywords=rca+antenna

I'm running it on it's own house battery/solar panel/charge controller, so it's stable enough. I'm an electronics fella, and even monitored the power over some time, so I think it's fine. Been running for months no problem.

On yours? I'd use the power supply mentioned early on on and not sweat it. Any voltage spike worth worrying about will probably take that out before the TV, but...no guarantees on that

gcsitts · Jun 23, 2014

Volts vs. Amps vs. Watts

scherzoja said:
I don't want to continue with the inverter because the 10:1 ratio of amps through the inverter seems like a horrible waste, since the TV is a 12v TV (once i wire it directly.

Before you go too far let's clear up the power issue; there is no 10:1 ratio of battery drain involved here. The TV takes a certain amount of power (watts) to run. Watts are Volts x Amps. If you have a 120 watt TV it takes either ten amps at 12 volts or one amp at 120 volts. Setting aside differences in efficiencies in various internal or external converters, the batteries are going to be depleted at the same rate whether you use an external inverter or the internally provided inverter.

There is some small efficiency gained in going directly to the 12 volt port on the TV because it bypasses the internal 120 volt to 12 volt conversion. But using a 12 volt to 12 volt bufffer block restores those inefficiencies.

Maine Sail · Jun 23, 2014

gcsitts said:
Before you go too far let's clear up the power issue; there is no 10:1 ratio of battery drain involved here. The TV takes a certain amount of power (watts) to run. Watts are Volts x Amps. If you have a 120 watt TV it takes either ten amps at 12 volts or one amp at 120 volts. Setting aside differences in efficiencies in various internal or external converters, the batteries are going to be depleted at the same rate whether you use an external inverter or the internally provided inverter.

There is some small efficiency gained in going directly to the 12 volt port on the TV because it bypasses the internal 120 volt to 12 volt conversion. But using a 12 volt to 12 volt bufffer block restores those inefficiencies.

Efficiencies gained can be quite a bit when staying DC or using DC>AC>DC.....

I've run the tests on numerous devices, the link below happens to be a TV, and inverters, and the range is wide but normally over 20% less efficient when using an inverter. I have seen some instances where it is in excess of 40% less efficient than DC...

Inverter & TV AC vs. DC Inefficiencies

Bill Roosa · Jun 23, 2014

Course it all depends on how much power the TV draws doesn't it? if it draws 1 watt (1/12 amp) and it is 50% efficient then it is drawing a wopping 1/6 amp!!! I don't think I care at that consumption. now if it draws 100 watts (8.3 amps) and is 50% efficient that would be 16 amps. Clearly not a great solution and you should to with a direct DC if possible. The reality is somewhere in the middle and depends on what your boat electrical system can handle.

tailwind · Jun 23, 2014

Where are all these voltage spikes coming from anyway? There's more opportunity for that from an AC line. I usually don't run or start an engine/generator when I watch TV. Makes it hard to hear. Solar panels are hooked up to a regulator, but if I turn the TV on it's usually after dark, anyway.

Allan12210 · Jun 23, 2014

Tailwind said:
Where are all these voltage spikes coming from anyway? There's more opportunity for that from an AC line. I usually don't run or start an engine/generator when I watch TV. Makes it hard to hear. Solar panels are hooked up to a regulator, but if I turn the TV on it's usually after dark, anyway.

Some spikes when the alternator or shore powered charger kicks on. Mostly just the wide range of voltage the TV will be exposed to....anywhere from a low battery condition (11 Volts) to batteries being charged (14.4 Volts). Its all good if the TV is meant to be exposed to that like mine is (used in RVs with the on board 12 V system). But, you don't know what a TV meant for normal household use with an AC to 12 Volt power supply might be able to handle if plugged into a variable power source. That's why it might just be prudent to use one of these DC-DC converters that will maintain a constant 12V out over a very wide range of input.

skeet · Jun 23, 2014

A battery is a really decent buffer against voltage spikes. That's why ya try not to run an alternator without it being hooked up to one.
Tech changes all the time... no ones knows it all, specially me... but from what I've seen, a battery is not a "pusher" of electrons into your TV. Your TV will use what it sees coming in. If it has the usual 2-3 amps available from a battery, all is good with it. Till not. Then it will stop working.
If your stuff like TV and SiriusXM radio are on their own, or close to it, house battery bank, there isn't any "spiking", unless it's EMF from somewhere else. That's a different thing.
I'd just use that power supply mentioned earlier and not worry too much.