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Discussion Starter · #1 ·
I'm giving yet another 12v TV a try. A Jensen. We'll see. I've returned other attempts.

I was thinking of hard wiring a voltage regulator into the line, so it always received 12v and not the higher voltages that actually come from the house bank.

Any recommendations on which?
 

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It depends upon the current draw, I have a massive (and expensive) 24VDC-12VDC regulator for my SSB, but that's because of the large amperages involved. A simple regulator that brings current down from up to 36VDC to a regulated 12VDC such as the 3Amp Tracopower TSR 3-24150 costs only $30 at farnell.com. The price is high because it is energy efficient, you can get a linear regulator such as the 511-L7812CV for about $0.70, but it would need a heat sink and use more power, especially in standby-mode. The input voltage must be at least 0.5V higher than the output voltage. If you need 12VDC output when the battery is less than 12.5V then a different device is needed, which adds to the cost.
 

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Discussion Starter · #3 ·
Requiring 12.5v sort of defeats the purpose, but would theoretically work the majority of the time.

I would like to think the Jensen 12v TVs, which are sold specifically for boats and RVs, are capable of taking a variety of input voltages. I just can't find a spec that confirms it. They are all written as "12v", which we all know is almost never actually the case in either a boat or RV.
 

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I bought a Carnetix DC-DC converter meant for car computers; gives a nice 12v (and 5v) well regulated. Not using it just now; my hair TV seems happy on ship's "12v".


Sent from my iPad using Tapatalk
 

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If you are slightly handy assembling electronics, you can by a Micrel 28000(many different versions with slightly different numbers) low-dropout regulator for 12 volts output. It requires only a couple of capacitors and a modest heatsink. It will regulate down to an input voltage of about 12.1 volts, at which point it will lose regulation and follow the voltage down. But at that point you shouldn't be watching TV anyway. I used these on a 19" TV and a 14" monitor for years. Last ones I bought cost a little over $3 at DigiKey
 

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Discussion Starter · #9 ·
I ended up installing a 24" Jensen, direct wired (via breaker) to the house 12v power. No invertor needed now, but still wonder if the Jensen has a regulator built in for the naturally varying house bank voltages. The unit is delivered with stripped leads to connect into 12v and is sold for RVs and Boats. One would think they might have thought of regulation. Anyone know? I see nothing in the manual.
 

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Uniformed opinion from an EE without any data is that if the manufacturer designed the thing for RV's and boats, they know that the input voltage varies during charging and discharge. I hope they aren't dumb enough to think otherwise. I have no spec, but if they didn't do this they are getting a pile of returns from people who aren't smart enough to ask the question you did....so my "guess" is that you are right, no regulator required.
 

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I ended up installing a 24" Jensen, direct wired (via breaker) to the house 12v power. No invertor needed now, but still wonder if the Jensen has a regulator built in for the naturally varying house bank voltages. The unit is delivered with stripped leads to connect into 12v and is sold for RVs and Boats. One would think they might have thought of regulation. Anyone know? I see nothing in the manual.
The specs say 12volt nominal which means variable heck the 120 ac power units work from 105 to 125 volts so one would assume that they already took on o account that the voltage would vary from 11 to 15 volts
 
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