converter buzz?

Discussion in 'Wiring' started by TDS-MN, Mar 3, 2014.

  1. TDS-MN

    TDS-MN Active Member

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    Hey All,

    I'm wondering if I should be concerned, when I've got the pup plugged in to shore power, my converter under the seat bench, really makes a pretty loud buzz. Almost to the point of being distracting when spending time indoors. So I am aware that the unit is 20 years or so old ( not sure of the make/model right now), but are new converters any quieter? I do NOT have a battery connected currently, and it does not appear that this pup ever had one in-place. I might be interested in that some day, but it's probably going to be rare that we will be camping somewhere without shore power available, in all honesty. So it's function is simply to take the 120v down to 12v for my lighting.

    Is there a way to simply not bother and have the shore power go direct to my interior outlets? I could live without the 12v lighting probably?
     
  2. pej

    pej Member

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    Working backwards, your lighting is all low voltage wiring, switches, and socket assemblies so it is best left installed as is. The only 120volt alternative would be a table lamp or floor lamp that would simply plug into your inside outlets. Realistically, you will continue to need a converter in your trailer to reduce the 120volts AC to 12volts DC and use the built-in lights.
    As for the buzz, your old 12v converter has a big transformer in it that is made up of a series of steel plates laminated together. As transformers age and get bounced around the plates separate a bit and then vibrate when in operation. It is not a safety concern, but it is annoying. A modern converter does not have a transformer so installing a new one would eliminate the buzz...forever. Newer converters do have fans, but they are generally quiet.
    A short term approach would be to try to quiet the laminated plates. First disconnect the trailer from shore power so you do not get a shock and then take the cover off the converter. If one end of the transformer plates are accessible, wrap a really tight layer of electrical tape around the plates so they are less likely to vibrate. Other than that, be happy that the noise drowns out the buzz of mosquitoes, or go shopping. On the plus side, if you ever decide to install a battery, the new converter will come with a good charger built in.
     
  3. tombiasi

    tombiasi Well-Known Member

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    Pej,
    Good words but instead of electrical tape around the lams we used to use a piece of no. 10 copper wire above and below the windings and twist it very tight. Some of the old transformers actually had thru bolts that could be tightened.
     
  4. pej

    pej Member

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    Yeah, i was leery about recommending anything conductive without knowing what is close by. A big hose clamp would tighten well. And yes, some transformers come with bolts and nuts that can simply be tightened

    Sent from my ASUS Transformer Pad TF300T using Tapatalk
     
  5. TDS-MN

    TDS-MN Active Member

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    Thanks for sharing your thouhgts. I am encouraged to hear that converter technology has changed enough over the years, that the larger transformers are not still being used. I know for sure that any cooling fan will be worlds quieter than what we have to deal with now. And I like the fact that a modern converter can also add the capability to recharge an on-board battery, should I ever decide that is something that I want to add.

    We actually haven't really used the interior lighting, I have been hesitant to have those bulbs on for very long, I have seen so many melted light covers over the years in various campers/motorhomes. I have been planning on an LED conversion for those, which would lessen the heat output of course. But for the time we spend indoors, it's usually enough with some portable LED lanterns so far. If it weren't for occasional use of the outside light, I could probably live with no low-voltage lighting on-board. I really just don't like the overhead light very much.

    But the 120V is something that we haven't been able to live without yet. And from the sound of it, if I were to swap out my converter, I would likely be much happier, and buzz-free. Once I do get the pup back out of hibernation, I will take a look and see if there is anything I might do to tighten/secure anything around the transformer/plates I have, in the mean time.

    Thanks again for your replies.
     
  6. arffch

    arffch Member

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    TDS-MN as far as melted covers go 12 volt lights come in diffrent wattages just like house lights. if the base is the same it will work. My camper is suppose to use 1141 light bulbs which are 18 watts. the one lens that was melted had a 1156 in it (26 watts) you can go the other way 97 bulb is 9.3 watts and a 67 is just 8 watts. By the way all those also come in amber, some are in other colors for mood lighting [:D]
     
  7. 1380ken

    1380ken Well-Known Member

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    My converter also buzzes. I am going to replace the lights with LEDs and replace the converter with a small 12v power supply.
     
  8. TDS-MN

    TDS-MN Active Member

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    I had seen your posting after entering mine. That should work for you. I had considered wiring my power cord direct to a small load center in place of the converter, and then doing the same, by splitting off the 12v lighting circuit from the 120v outlets, provide the quiet 12V power supply, and connect my 120V outlets to a circuit breaker. I think I could do that for less than the cost of a new converter, but would be limited in the long run, should I ever want to add on-board DC power via battery.
     
  9. TDS-MN

    TDS-MN Active Member

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    I have found the 1141 in my interior light fixture, but still find the lens cover to be fairly hot to the touch, and therefore limit how much we turn those on anyway. I figure that an LED conversion should help some at least. But you make a good point, if a higher watt were used, that woud very likely melt its way thru fairly quickly. You did start me thinking of the lower watt approach, though, for a different approach.
     

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