Inverter Question

[Chester Taje]

I have a 300 watt Go Power inverter. When i plug it into the trailer 12volt outlet and then plug my television into it the inverter starts to whistle. I also have a battery power pack and when i plug inverter into that it works normally till power pack (Jump It) goes dead. When power pack is losing its charge then inverter starts to whistle. This last part I can understand do to power pack power being depleated.
Power pack will run television for about 6 hrs with no problem.

[Darwin Maring]

I think it is the electronics that is making the sound. Even though it is a solid state chip with no moving parts I think by taking the DC and vibrating it through a transformer it tends to make the electronics like the transformer make a noise.

I notice the same thing on high end battery powered drills (Milwaukee). I think they are doing the same thing to better control their devices.

[Al V]

Check the voltage at the inverter while under load. the eggs wiring might not big enough to support the load.
or try the inverter when it is connected directly to a big battery. if it still makes noise then its is the inverter if it goes away then it would be voltage drop in the camper.

[Casita Greg]

Chester,

Under various fault conditions, and sometimes when lightly loaded, there may be tell-tail audible indications of the inverter's state of happiness. The cause may be in the inverter itself, or its load.


1. Tweet-tweet-tweet or chirp-chirp-chirp (sometimes flub-flub-flub) - Short circuit or current overload. This is usually an indication of a shorted secondary-side rectifier and/or if in a TV or monitor using an inverter, a shorted horizontal output transistor. The power supply is in a repeating cycle attempting to start up, being dragged down by the overload, and shutting down.

2. High pitched, but audible, whine - Could be excessive load on the inverter. The result is an overload and whine, but usually not a catastrophic failure of anything else. Could also be caused by low input voltage to the inverter, (i.e. low 12vdc battery supply voltage). (Since a transformer's output is directly relational in proportion to it's input, low voltage in-low voltage out.)

Which of (1) or (2) actually present will depend on the particular design of the inverter and the severity of the overload. If the design uses a hard SCR crowbar, an overvoltage condition may trigger one of the symptoms!

3. Tick-tick-tick - Too little or no load. In a TV or monitor using an inverter, this is likely due to a lack of horizontal drive or a blown fuse or fusable resistor in the horizontal deflection system. The power supply is in a repeating cycle of starting up, being unable to limit the regulated voltage to a safe value, and shutting down. Attempting to power up an inverter without an adequate dummy load may result in these symptoms.

4. Hissing or white noise - possibly from inductors - this may be normal under certain conditions.

Not sure if this is relative to the problem you describe, but with the info you provided, it's what comes to mind. I'm inclined to think that it would be #2 above, more so, than the other reasons. Hope it helps.

Greg

[Morgan]

I have a 300 watt Go Power inverter. When i plug it into the trailer 12volt outlet and then plug my television into it the inverter starts to whistle. I also have a battery power pack and when i plug inverter into that it works normally till power pack (Jump It) goes dead. When power pack is losing its charge then inverter starts to whistle. This last part I can understand do to power pack power being depleated.
Power pack will run television for about 6 hrs with no problem.

Maybe it's afraid of the dark.

Seriously, Ches, it may be your converter. Does this whistling occur when you're connected to ground power? Try unplugging the ground power and see if it still whistles.

The first thing you should do, though, is check the television and any other loads for power consumption. If they use more than 300 watts total, that's probably your problem.

[Chester Taje]

I will look at all suggestions and get back to you all. Thanks

[Chester Taje]

I just got some info back from the folks who make this inverter. I had placed a help call yesterday to them. I also posted here at same time.

The info i got back was that the whistling noise is a low voltage indicator. The wattage i want to use is 65 watts for television and 35 watts for sat receiver. My units batteries are 2-6volt and fully charged. I am thinking that the wiring in trailer is not big enough to get power to inverter. I will be going out when rain stops and try again.

[Al V]

ooo ooo do i win a prize :rofl

[Chester Taje]

I have done some testing. When power is on in trailer and i plug inverter into a 12volt outlet then plug television (110) into inverter it works as it should. When i turn main power off to trailer and just use batteries it only lasts a few min then starts to whistle. I am going to town to get some wire and then see if that makes the difference.

[Chester Taje]

No wire in town. Going to experiment.

[Chester Taje]

Experiment continues. I took Inverter out side right next to battery. I then put wires direct to Batteries. I now have a 50ft extension cable running into trailer from inverter and everything to this point in time works great. I will leave on for a few hrs and see what happens.

[Chester Taje]

Well i got system working. I firmly beleive that 12 volt outlet wiring in trailer is not adequate for the inverter to draw power from. I have installed a 12 gauge wire from battery which i found in my junk and placed inverter closer to battery. I then ran a short extension cable to television. This is working very well. Tomorrow i will install it permanitly.

Thanks to all for there ideas.

[Ed Harris]

Ches
This type of Voltage drop is a really common issue in 12volt systems and I think this chart speaks to it directly,

http://www.solarseller.com/dc_wire_loss_chart___.htm

It seems clear that the losses can be dramatic and these values represent just the 1-way losses in a 12vdc system so double them for the complete circuit.

I think we tend to minimize the importance of wire size over distance as they are so different in our more typical 120vac sysytems.

So the solution you found seems the clear one as I have read everywhere quality inverters are sold.
Notice that most inverters that have an input cable,have a short one attached but they also have just an normal houshold AC output plug with no warnings about the length of extension on the output?

Ed

[Chester Taje]

Thats good info Ed. Thank You

[Frederick L. Simson]

Maybe it's afraid of the dark.

Because it doesn't know the words?

[Morgan]

Because it doesn't know the words?

He didn't say it was humming, Frederick.

[Bill K]

After having the same thing happen to me, I read my manual and found out that when my 300W inverter is plugged into a 12v outlet it is only good for 180W.

I ran a + & - directly to my inverter and now have the full 300W.

Bill K

ps My Laptop uses 204W which is how I found out about the noise. LOL