My trailer is whining!

thecatsandi · 09-17-2007, 01:37 PM

Ok so my trailer is not whining I am!

I have noticed when I have my stereo is on and the furnance kicks on, i get increased converter whine.

I have come up with two possible solutions. Put a high current choke and large capacitor in the system just after the converter output.
or: Put a choke on the power line for the stereo.

I liek the idea of filter all of the DC out of the converter since it kep all the power clean. I also have easier access to the converter than the power for the stereo.

Has anyone else had this problem and solved it?

HiHoAgRV · 09-17-2007, 02:23 PM

RFI (Radio Frequency Interference) could be coming from the heaters fan as well. Either way it's a two fold problem, conducted and radiated. Conducted comes from the noise generator, down the wire into the radio. Radiated is a bigger problem because the wires all act like antennas and the noise will jump around any chokes.

Try shutting off the converter, then firing up the heater to see if the problem is coming from the fan. If so, put a choke in the power line right at the heater. If it's the converter, put it at the radio or if you can get one rated for the full amp output of the converter install it there.

thecatsandi · 09-17-2007, 08:24 PM

I will check that out. I suspect the converter since the noise gets louder when the furnance runs. the pitch of the noise does not change.

Melody Ranch · 09-17-2007, 08:58 PM

Michelle,
Did you say "when the furnace kicks on.....? Darn!

Its still September, mid nintys with heat warnings put out with the morning weather report....When is fire season over and we can expect you to pass thru to warmer climes?

Janet's Husband · 09-17-2007, 09:05 PM

Quote:

Originally Posted by thecatsandi

I will check that out. I suspect the converter since the noise gets louder when the furnance runs. the pitch of the noise does not change.

Michelle

The battery(ies) act in conjunction with the converter to act as a filter for noise. There are a few things that can cause an increase in ripple on a charging system. ie. Poor connection to battery or charger, bad battery, or the converter is on its way out. I would see if you can find the ripple spec. on your converter. Use a Voltmeter on AC across the converter output and see what you read. I would think you should see about 350 mv rms max. That is just a guess. The chargers I use at work are rated at ripple less than 15 mv PP. Nose around and see what has changed in your DC electrical system.

thecatsandi · 09-18-2007, 09:19 AM

Yes the furnace. It is getting cool in the evenings in Boise. We are "high" desert.

Fire season should be over soon. I expect to be out of here in two to three weeks. Back to Oregon until Mid November. Then Back to Boise for a couple of weeks and then east for Christmas. I will not be heading the southern route until after the can opener.

thecatsandi · 09-18-2007, 09:53 AM

Gary,
I am getting 12.8 mv ripple without the furnace running. 16.1mv with it running. Not much. I may have coupling on the speaker wires with the power wires. I am going to put a choke on the stereo and see what happens.

thecatsandi · 01-03-2008, 09:35 AM

A little update. My converter died. See the other thread. It was replaced with an Intellipower 9600 series. Most of the whine went away. I only hear it in the rear speakers now.