Buzzing noise

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1930

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Put a flat screen TV in my old camper, it's 12 volt and I ran a cigarette lighter outlet to my TV to plug in.

I've been using it under battery power and no issues, last night using my generator I couldn't get any volume other than a buzzing noise.

I'm gonna guess I need some kind of noise suppresor and am hoping there is something I can use between the outlet and the cig. adapter so it's quick and easy and I can watch TV tonight?
 

HappyWanderer

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"Old camper" is the key. Older converters had little to no filtering, so the DC power they produce can be pretty dirty. It's basically a battery charger - RVs didn't used to be loaded with electronics. Your best option is probably replacing the converter.
 

John From Detroit

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I agree. . The old Magnetek converters (to name one) had two DC circuits. Blue and Red wires. one was the battery charge. Barely enough to run the TV. But it should run it well.  Without a manual I'm not sure which fuses are connected to that circuit. (I think but again I'm not sure it's the blue wire)  The other circuit had zero filtering. it's not DC but Rectified AC either 60 or 120 HZ.. Does not matter if you are on shore or generator power.

And I'm surprised the TV ever worked if hooked to that.

The solution is to upgrade the converter by replacing the "Guts" with a Progressive Dymaics 4600.. but for now.. Try changing the circuit for the TV.

The old Magnetek's also liked to boil batteries dry.

 

spdracr39

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You are also supplying really dirty power with a contractor generator. This is a primary reason to use a pure sine wave inverter generator. It isn't as big of a deal for the 12 volt items but it will put off a lot of interference and could cause your converter to do the same.
 

1930

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OK well that stinks, worked great when I was just using my battery.

Stupid question but was I supposed to do anything inside the camper when I hooked up the generator?

I mistakenly left my battery at home on the charger, I had my generator so I didnt care, I just turned generator on, plugged camper in and was surprised/happy that everything worked.

Maybe I didnt follow some special step for the camper when hooking up a generator?
 

HappyWanderer

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You're using the generator and converter without the battery being installed? If so, that explains a lot.

When using the converter, the battery will act as a big capacitor - filtering the 12 volt power from the converter. Your TV might be okay when the battery is installed.

It worked fine with just the battery, because the battery supplies pure 12 volts DC.
 

1930

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HappyWanderer said:
You're using the generator and converter without the battery being installed? If so, that explains a lot.

When using the converter, the battery will act as a big capacitor - filtering the 12 volt power from the converter. Your TV might be okay when the battery is installed.

It worked fine with just the battery, because the battery supplies pure 12 volts DC.

Im glad I asked then.

Not sure when Im gonna get out there again ( 2 hr away ) but when I do I will install the battery and will update the thread
 

1930

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HappyWanderer said:
You're using the generator and converter without the battery being installed? If so, that explains a lot.

When using the converter, the battery will act as a big capacitor - filtering the 12 volt power from the converter. Your TV might be okay when the battery is installed.

It worked fine with just the battery, because the battery supplies pure 12 volts DC.

Wouldnt it be alot easier ( and cheaper ) rather than start looking at converter swapping to just run a wire directly off the battery to my cigarette lighter plug so that I can watch my TV? ( assuming theres still the buzzing noise even with the battery installed)
 

Alfa38User

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Most likely your TV is 120 Volts, not the 12V that comes from a battery. There are 12V TV's, of course, but you may or may not have one. There may or may not be the buzzing but there is only one way to find out!!
 

Gizmo100

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1930 said:
Wouldnt it be alot easier ( and cheaper ) rather than start looking at converter swapping to just run a wire directly off the battery to my cigarette lighter plug so that I can watch my TV? ( assuming theres still the buzzing noise even with the battery installed)

You may luck out and everything will be fine once you have the battery installed. Otherwise you may need to look into a noise filter. Going straight to the battery would likely not help anything. 
 

Gary RV_Wizard

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In the first post he stated it is 12v, so it ought to work.

Before we get too far down the converter noise path, just how much "older" is this camper?  Probably would have to be more than 20 years old...
 

HappyWanderer

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1930 said:
Wouldnt it be alot easier ( and cheaper ) rather than start looking at converter swapping to just run a wire directly off the battery to my cigarette lighter plug so that I can watch my TV? ( assuming theres still the buzzing noise even with the battery installed)

The noise is on the DC side of the converter, so any difference is unlikely. I wouldn't do anything until you see how things work out with the battery installed.
 

Alaskansnowbirds

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You stated it is a 12V TV. Did it come with a power cord so you could plug it into 110VAC? If so use that and use the 110 from the generator to power it for this trip.
 

1930

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Alaskansnowbirds said:
You stated it is a 12V TV. Did it come with a power cord so you could plug it into 110VAC? If so use that and use the 110 from the generator to power it for this trip.
12 volt only as far as I know.
 

1930

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Three days off and I plan to go back to property, Id like a TV

Worst case scenario is I buy another battery dedicated to just the TV which isnt a big deal but lets say I put my battery back in the camper and buzzing noise still there, can I remove the battery and just not have a battery in the camper for any length of time?

I can hotwire the TV easy enough to the 12 volt cig lighter deal so I can turn the TV on.
 

Gizmo100

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I would try with the battery installed before I went out and bought another one.

As far as running the converter without the battery...

That's a question only you can answer. Some converters will run fine without a battery other will provide strange voltage surges.
I would not to want to run without the battery because it helps balance the voltage. I have a gut feeling that once you reinstall the battery the hum will be reduced or go away.
 

Old_Crow

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I think Gizmo is probably right.  In my old '89 coach you could hit the battery disconnect switches when the coach was plugged in to shore power and the radio would buzz really bad while running off the converter only.  If you reconnected the batteries the buzz went away.
 

1930

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Ok thanks, so would that mean I need to find a battery disconnect switch in my camper and use it when my generator is hooked up?
 
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