cjac Posted July 29, 2017 Share Posted July 29, 2017 When I plug in to shore power I get a buzzing noise through my tv. My converter hums a little. The hum through the TV started a couple week ago . The TV is 12v Quote Link to comment Share on other sites More sharing options...
Derek up North Posted July 29, 2017 Share Posted July 29, 2017 Does the TV buzz only when plugged into shore power? Any chance you could see if a different TV buzzes as well? Did the converter start humming at the same time? Quote Link to comment Share on other sites More sharing options...
Maineah Posted July 29, 2017 Share Posted July 29, 2017 The original converters were not real clean electrically. The TV also probably has pretty poor line noise rejection on 12 volts. If it's something new it could also be a tired filter cap in the power supply, caps do age and remember you're dealing with 30+ year old electronics. Quote Link to comment Share on other sites More sharing options...
neubie Posted July 29, 2017 Share Posted July 29, 2017 The usual cause of this is capacitors slowly getting tired and then pushing the problem downstream to plugged in electronics. The actual humming noise emnates from some transformer. Its not just the voltage without load, which is never 12V by the way, but the variation in the DC output voltage as supply varies. The TV humming will go away if its supply is cleaned up. If the TV is relatively modern then it probably doesnt draw very many amperes. In that case it would run on a lithium ion charger battery. If it does, then that battery can act as a buffer between the convertor and the TV. Quote Link to comment Share on other sites More sharing options...
cjac Posted July 29, 2017 Author Share Posted July 29, 2017 Ok I'm not to much on the electric stuff lol. Well I have no hum in the TV now. I've been plugged in to shore power for an hour and have the a/c on and the refrigerator running still no hum in the TV. Idk probably need to upgrade . What's good on the market? Quote Link to comment Share on other sites More sharing options...
Nam Posted August 1, 2017 Share Posted August 1, 2017 I replaced mine with this. Not only it helps with supplying clean 12V DC but it helps with the battery as well. I am happy with it. The onlý issue is it sucks 740W when charging the battery so my 2000W honda generator cannot handle this guy and powering the AC at the same time. Progressive Dynamics (PD9245CV) 45 Amp Power Converter with Charge Wizard https://www.amazon.com/dp/B000GANZZ6/ref=cm_sw_r_cp_apa_K4hGzbN8V3JJD Quote Link to comment Share on other sites More sharing options...
Gulfstream Greg Posted August 1, 2017 Share Posted August 1, 2017 Humming out of the speaker? That converter is a half wave diode rectified type power supply. With no filtering. The humming is probably AC voltage in the circuit. The two diodes are to the left of the transformer. A full wave rectified power supply will have 4 diodes. If you have a multi meter set it to AC then take a reading on your 12 volt circuit when plugged into shore power. If you get a AC voltage reading then that is bad for any 12 v DC electronics. Most 12 v DC electronic devices do not have the proper filtering to filter out the AC from a half wave rectified power supply and could eventually get smoked! Another problem with those converter / power supplies is the battery charger which will over charge the coach battery. That converter also disconnects the coach battery from the 12 v dc circuit and connects it to the battery to the charger when plugged into shore power via the relay to the right of the transformer. I have replaced my last two MH 6300's wit these http://www.parallaxpower.com/6345ru-replacement-upgrade-6345ru . Basically plug and play with no major retrofit modifications. Quote Link to comment Share on other sites More sharing options...
cjac Posted August 2, 2017 Author Share Posted August 2, 2017 Thanks for the info Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.