Question about wiring DC input into boombox

Cheburashka · Aug 10, 2012

This seems like a no-brainer, but I've blown this before so I thought I'd check. I'm trying to put a boombox in my travel trailer. I'm looking at the Naxa Naxa NPB-255, which takes 8 D-cells. I figure that's 12 volts--right? (Last time I tried, I multiplied 6 by 1.5 and got 12. )

I'm thinking I can solder a double power cord directly to the battery terminals and plug that into the 12 volts the trailer gets from its automotive-type battery that runs the accessories.

Assuming I get my positive and negative in the right places, is there a chance that I'll blow it up due to excessive amperage from the car battery?

Thanks

john monks · Aug 10, 2012

Unlikely but it might be wise to wire in a 1A fuse. Maybe more depending on how loud you like your music. You might also consider wiring in a rectifier to be sure you don't hook it up wrong.

KJ6EAD · Aug 11, 2012

Doesn't the boom box have a coaxial DC input jack?

shrtrnd · Aug 12, 2012

I'm in agreement with john monks.
Your car battery gives very clean DC voltage, but if it's wired to the alternator, you'll
see occasional (small) voltage fluctuations.
I'd pick off the voltage after your car's voltage regulator (then you wouldn't need a separate
rectifier), and make absolutely sure you use a fuse to the radio, in case any kind of
voltage spike ever hits the system (with autos, you never know).
If your travel trailer has a separate battery (not tied to the alternator in your vehicle)
you just need the fuse.
In any case, john monks fuse idea should protect your radio.

Cheburashka · Aug 13, 2012

Thanks.

Since it's only going to be used while the trailer is parked, there shouldn't be any problem with voltage fluctuations. I'll wire in a 1amp fuse and see what happens.

shrtrnd · Aug 13, 2012

I'm wondering if we've got the full story.
You mean the trailer will be parked, no vehicle operating, and you're just running off
a 12V auto battery?
Are you plugging into an outside AC power source, and recharging your battery off of
that?
This seems like a simple question, all we're worried about is what else might be
in your circuit (it matters).
If you're just running your radio and maybe trailer lights off your battery when the vehicle
is not running, you've got a steady DC voltage.
If you're operating something else while you're listening to the radio, no matter how
insignificant you think it might be, it might matter.

Cheburashka · Aug 13, 2012

The trailer has a 12V storage battery that's charged by the tow vehicle. It's used only for led lights, the sink pump, and a carbon monoxide detector. When the trailer is in use, it's not attached to the tow vehicle so there can't be surges from the alternator. If I'm hooked up to 110 AC, I'll be able to plug it in directly with the plug that's provided, so this is only for times when 110 AC is not available.

shrtrnd said:

I'm wondering if we've got the full story.
You mean the trailer will be parked, no vehicle operating, and you're just running off
a 12V auto battery?
Are you plugging into an outside AC power source, and recharging your battery off of
that?
This seems like a simple question, all we're worried about is what else might be
in your circuit (it matters).
If you're just running your radio and maybe trailer lights off your battery when the vehicle
is not running, you've got a steady DC voltage.
If you're operating something else while you're listening to the radio, no matter how
insignificant you think it might be, it might matter.
Click to expand...

Question about wiring DC input into boombox

Cheburashka

john monks

KJ6EAD

shrtrnd

Cheburashka

shrtrnd

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