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Author Topic: 12VDC for DVR?  (Read 1566 times)

Old Blevins

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12VDC for DVR?
« on: September 27, 2014, 07:42:58 PM »
I'm buying a Channel Master DVR+ which will mostly get used in our TT.  The power cord plugs into 120VAC and provides 12VDC to the DVR.  Channel Master does not make a 12VDC cord for the unit.  I'm thinking of finding a plug that fits and wiring my own for direct connection to my 12VDC socket.  I'm pretty sure this will work. (Hey, it works for my CPAP.)  But "pretty sure" is nervous time with a new $250 unit.

Yes, I could get an inverter, but the extra power consumption of the conversion (both ways!), the noise of the inverter fan, and the cost of the inverter are all drawbacks.  I like simple.  But... am I being simple-minded?  Any obvious reasons anyone can see why my diabolical plan won't work?
Jim
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2006 Silverado SRW 1-Ton 4WD Diesel
2006 Arctic Fox 29V
1985 Brawley 2-Horse Straight-Load Trailer

Molaker

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Re: 12VDC for DVR?
« Reply #1 on: September 27, 2014, 07:49:37 PM »
Just match the current capability (fused) with the rated current demand and make sure your polarity is correct and you should be okay.  Do it quick while the warranty is still in effect. ::)
Tom & Joyce and Ditto the "don't tell her she's a dog" Westie
U.S. Navy (Ret)
2014 Winnebago ERA 70X 24' class B Sprinter chassis

Gary RV_Wizard

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Re: 12VDC for DVR?
« Reply #2 on: September 28, 2014, 10:17:30 AM »
Make sure it is 12v to the DVR - I've seen electronics at anywhere between 5v and 18v. The 120v power supply should have an output DC voltage and amp rating on it, so match that.
Gary
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John From Detroit

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Re: 12VDC for DVR?
« Reply #3 on: September 28, 2014, 02:44:36 PM »
Radio Shack sells a cord, with a special end, and then they have an assortment of "Power Tips" you can find one that matches more than likely. NOT the cheapest way (I buy a solder on tip and make my own cords, this is cheaper) but they work well...

The only caution I will give is this: Many people are concerned that the battery voltage in an RV is not 12, but usually 13.6  and can be as high a 15-16 in some cases... They feel that 12 volt items may be damaged by this higher voltage.

I, have measured the no-load voltage on some of the wall warts and power bricks.. it says 12, but may well put out 14-16 NO LOAD.

Thus I'm not sure those concerns are valid..... But if you are worried, it can be fixed easily enough.   There is a box that takes like 9-30 volts in and outputs .. a Fixed voltage (I think the normal one is pre-set to 13.6 but I'm not sure since I do not use one)

I believe Gordon West mentioned it the Sept-17 edition of Ham Nation (http://twit.tv./hn  not sure of episode number but it mentions DX in the title)
Direct link:  http://twit.tv/show/ham-nation/165
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Old Blevins

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Re: 12VDC for DVR?
« Reply #4 on: September 28, 2014, 05:27:14 PM »
Make sure it is 12v to the DVR - I've seen electronics at anywhere between 5v and 18v. The 120v power supply should have an output DC voltage and amp rating on it, so match that.
Good point, Gary -  when it arrives tomorrow I'll double-check it.

John, I think you're right about the caution as to the variability of the DC voltage.  I hadn't thought of that, but I think I can avoid most of that by using the direct 12V connection only when I'm not on shore power.  When I'm on shore power and my converter is in play, I'll use the supplied 120VAC plug.

Thanks, all.  I'll post later on the results and what I think of the DVR.  Being able to record Over-The-Air transmissions and play them back with a DVR is something others might be interested in.

Cheers!
Jim
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2006 Silverado SRW 1-Ton 4WD Diesel
2006 Arctic Fox 29V
1985 Brawley 2-Horse Straight-Load Trailer

thesameguy

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Re: 12VDC for DVR?
« Reply #5 on: September 29, 2014, 10:25:11 PM »
I use these things:

http://www.mini-box.com/DCDC-USB

to run flatscreens and computers.

It takes a variety of input voltages and provides a preset, constant output voltage. It's nice because it can handle a deeply discharged battery all the way to full alternator voltage and keep regulated power to your device. This is the heavy duty version and can supply up to 10a, but elsewhere on this site are lesser versions for less money.


Sloop

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Re: 12VDC for DVR?
« Reply #6 on: September 30, 2014, 10:58:25 AM »
I installed a DC/DC 24V/12V Step down converter on one of my 12V outlets to run TV's, DVD players and computers off.  It has an input range of 12V - 40VDC and will maintain a constant 12VDC output unless the inout voltage drops below 12VDC. That way if the converter kicks up to 14 - 15VDC that outlet remains constant at 12VDC.

http://www.ebay.com/itm/SUPERNIGHT-DC-DC-Converter-Regulator-Voltage-24V-Step-Down-to-12V-20A-240W-/231089898995?pt=LH_DefaultDomain_0&hash=item35ce0805f3#ht_2132wt_982
1992 24' Fleetwood Class "C" Jamboree Rallye
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Old Blevins

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Re: 12VDC for DVR?
« Reply #7 on: September 30, 2014, 01:04:40 PM »
Both the input of the DVR and the output of the DVR power cord say 12VDC (nice that they match, eh?)  So I'll see if I can get a plug today that fits and try it out.  In a few days I'll post about the Channel Master - probably in the PCs, Communications, Electronics board.
Jim
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2006 Silverado SRW 1-Ton 4WD Diesel
2006 Arctic Fox 29V
1985 Brawley 2-Horse Straight-Load Trailer

Old Blevins

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Re: 12VDC for DVR?
« Reply #8 on: September 30, 2014, 03:49:04 PM »
Okay, I got the connectors and bread-boarded the DVR to a spare battery I had.  It works.  It draws less than 2A at 12V, so 2 hours of TV an evening will cost me less than 4 AH.   More in the PCs, Communications, Electronics board if you're interested.
Jim
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2006 Silverado SRW 1-Ton 4WD Diesel
2006 Arctic Fox 29V
1985 Brawley 2-Horse Straight-Load Trailer

 

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