12V AC?

[Jay H]

I installed some LED light panels in my Boler and when I use shore power they strobe/ flash. I have the original Allanson converter in the Boler and I am pretty sure that I have it wired correctly. So, here is the part that confused me; when I used my volt meter to check the wiring it read that I was getting AC voltage (14?v) when I was running off of shore power. I thought the converter actually converted the AC to DC.
Any thoughts?

[rbryan]

Originally Posted by Jay H

I installed some LED light panels in my Boler and when I use shore power they strobe/ flash. I have the original Allanson converter in the Boler and I am pretty sure that I have it wired correctly. So, here is the part that confused me; when I used my volt meter to check the wiring it read that I was getting AC voltage (14?v) when I was running off of shore power. I thought the converter actually converted the AC to DC.
Any thoughts?

A common cause for strobing/flickering is a ground fault.

[Jay H]

yep, that is what I figured. in fact the LEds were working properly last week then I broke the ground blade off of my shore power plug. i put a new plug end onto the cable and here is where I am.
As for the ground, the breaker box is grounded well to the frame. I braided 4strands of romex wire together, took a grinder to the frame and screwed into the steel. Since I just installed electric brakes yesterday I also have a ground off of the negative lead on the battery (otherwise the brakes won't actuate) also onto the frame.
so what did I do wrong?
And I still would like to know if the current is suppose to be ac or dc...

[rbryan]

Originally Posted by Jay H

yep, that is what I figured. in fact the LEds were working properly last week then I broke the ground blade off of my shore power plug. i put a new plug end onto the cable and here is where I am.
As for the ground, the breaker box is grounded well to the frame. I braided 4strands of romex wire together, took a grinder to the frame and screwed into the steel. Since I just installed electric brakes yesterday I also have a ground off of the negative lead on the battery (otherwise the brakes won't actuate) also onto the frame.
so what did I do wrong?
And I still would like to know if the current is suppose to be ac or dc...

All of your interior wiring for fixtures and such is 12 volt. And yes, the converter turns shore power into DC power. I'm assuming the leds are just 12v dc fixtures. Its not usually an issue if the output voltage is a little higher than 12 volts, so I don't think the flickering is an overload issue.

[Jay H]

Originally Posted by rbryan

All of your interior wiring for fixtures and such is 12 volt. And yes, the converter turns shore power into DC power. Its not usually an issue if the output voltage is a little higher than 12 volts, so I don't think the flickering is an overload issue.

I understand that voltage can run higher, maybe even intothe 15 volt range but why is it AC? I connected my voltmeter to the wires when I was running off the battery and I got a solid DC reading (12.8v). When I swithced the converter to shore power I had to flip my voltmeter to AC (it read 0v on DC) and I got 14v AC.
I am not worried about the voltage output, I am confused why it is AC.

[rbryan]

I guess I'm not understanding "switching the converter" part of it. Mine automatically kicks in when i plug into shore power, and outputs 12v DC. Are you saying the voltage at the fixture is AC? If so, that's a wiring issue with the converter. What exactly, I don't know. But the converter should only output DC power.

[Jay H]

yep. That is exactly what I am saying. And I don't understand why it is AC at the fixture. My understanding of a converter is just that, it converts AC to DC. So what is going on?

[Frederick L. Simson]

Originally Posted by Jay H

I have the original Allanson converter in the Boler and I am pretty sure that I have it wired correctly. So, here is the part that confused me; when I used my volt meter to check the wiring it read that I was getting AC voltage (14?v) when I was running off of shore power. I thought the converter actually converted the AC to DC.
Any thoughts?

Are the new LED panels the only lighting in the trailer now? Have you tried to reconnect the old incandescent 12 volt lights to see if that works? Feels like you're putting new wine into old wine skins, to use a biblical metaphor. The LED lights may require you to upgrade the converter also. I've had to upgrade both of my trailers' converters.

[Byron Kinnaman]

OK Here's what's going on the converter is cycling. (I've seen it happen). The converter see's the battery a little below full charge so it attempts to charge, then sees the battery with a full charge and stops charging only to repeat the cycle. This is caused by a small voltage loss in the wire between the converter and the battery and a cheap converter without built in hysteresis. Turn off the converter and the problem will go away.

Cheap DVMs will often read DC on the AC scales.

[Jay H]

Yes, everything is LED now. I thought about replacing the converter but I was told it was solid and there was no need.
Here is the crazy thing, 2 weeks ago I didn't have a battery. in fact the boler doesn't seem to ever had a battery. I installed the lights, and ran them off of shore power fine for a month in my garage while I was renovating the trailer. They didn't flicker. But I never thought to check the AC\DC output.
I only changed two things to the electrical in the past month. 1- I replaced the plug end on my power cord. 2 - I added a battery.

[Jay H]

Originally Posted by Byron Kinnaman

OK Here's what's going on the converter is cycling. (I've seen it happen). The converter see's the battery a little below full charge so it attempts to charge, then sees the battery with a full charge and stops charging only to repeat the cycle. This is caused by a small voltage loss in the wire between the converter and the battery and a cheap converter without built in hysteresis. Turn off the converter and the problem will go away.

Cheap DVMs will often read DC on the AC scales.

You are correct. When I shut off the converter and run straight from battery, everything is perfect, no flickering (sorry I did not clearly explain that).
If the converter is cycling, will it stop cycling or is it caught in an endless loop?

I have 3 volt meters. An old anolog needle meter, I will check ac vs dc tomorrow and a cheaper Canadian Tire digital meter that I used today. Do you think the AC/DC issue is really a cheapo meter error? My probably still cheap but more expensive volt meter just confuses me mostly...

[Jay H]

Do you want to hear another part of the story that I didn't include because I didn't want to muddy the waters more?
I bought those little round LED touch lights as reading lights for the kids and wired them in by the bunks. You know the ones where there is no switch, you just touch the light and it comes on and when you want to shut it off you touch it again. Well, with my current situation, they work great on battery power but when I switch the converter to shore power the lights come on by themselves and wont shut off (whos brilliant idea was it to install a light without a switch!
It's like a disco party that just won't stop!)
They won't turn off until you switch the converter back to battery.
I hate wiring.

[steve dunham]

AC ripple is not uncommon on the old style converters. They had very poor regulation ,
filtering and rectification . The AC ripple would often cause newer sensing devices to overheat .
The newer regulated power supplies give out a much cleaner DC with far less ripple

[rbryan]

Long term, replace the converter.


Sent from my iPhone using Fiberglass RV

[floyd]

Originally Posted by Jay H

I installed some LED light panels in my Boler and when I use shore power they strobe/ flash. I have the original Allanson converter in the Boler and I am pretty sure that I have it wired correctly. So, here is the part that confused me; when I used my volt meter to check the wiring it read that I was getting AC voltage (14?v) when I was running off of shore power. I thought the converter actually converted the AC to DC.
Any thoughts?

I have found that when a cooling fan in a converter fails, it often "pulses" the lights as it tries and fails to rotate.

[redbarron55]

The battery is the filter for older poorly filtered battery chargers. If the battery is fully charged then it doesn't do much filtering.
Even good meters can under some circumstances read pulsating dc as ac. The ripple could be enough to read. A good Fluke meter will read the amount of ac ripple on top of the dc signal. Good for checking for ripple.
At what rate are they flickering?
It is possible you have an open filter capacitor in the power supply.
In this case you will get lots of ripple after the battery has charged.

[Darwin Maring]

I think you need to connect it to a silly scope (Osilliscope) to see what it is. AC at 60cycles or pulsating DC.

[Bob in Mb]

I had the same problem a new converter solved it totally , plus the old one hummed constantly and the new one does not make a sound .

[Jay H]

well, sounds like a new converter is on the list. That's a bit of a disappointment. It's definitely not going to happen before the end of summer, we have been working like mad to finish the Boler reno for a big trip to the Rockies, planning on leaving Saturday so no time to replace the converter before then.
I was planning on camping in non-electrical sites anyway. Use the solar to recharge the deepcycle if I stay more than a day or two.
Thanks for all the help.
Jay

[Jay H]

Originally Posted by redbarron55

The battery is the filter for older poorly filtered battery chargers. If the battery is fully charged then it doesn't do much filtering.
Even good meters can under some circumstances read pulsating dc as ac. The ripple could be enough to read. A good Fluke meter will read the amount of ac ripple on top of the dc signal. Good for checking for ripple.
At what rate are they flickering?
It is possible you have an open filter capacitor in the power supply.
In this case you will get lots of ripple after the battery has charged.

I am not really sure what rate they flicker at. It is a pretty fast rate, not enough for the ambient light to dim at all. I am really not well versed in electronics, so I have no idea how to tell if I have an open filter capacitor.

But, can you tell me, if the battery is partly discharged will the ripple disappear ?