LED retrofit for a 120 volt 100 Watt halogen lamp?

We have 3 dimable halogen lamps in the saloon that run off A/C on inverter power. Needless to say they are power hogs but they ate really nice lights. Does anyone have any bright ideas on how to retrofit them?
Here is one of the lights...




Here is the halogen bulb used...




Jim, Sent from my iPad using Trawler

Jim: We've converted 3 AC halogens to 3 DC LEDs, 2 wall dimmable wall lights and 1 desk light. We ran DC to the light, took out the AC parts and just left the switch. Installed the LEDs in place of the halogens. The LEDS and sockets were what we had laying around at the time. On the desk light, we added some lead sinkers at the base to give it some weight when the transformer was removed. We did loose the ability to dim the lights though.

Thanks Larry. I had thought that running DC wiring would be the probable solution. So the dimers on the fixture no longer work?

Jim

Jim, Sent from my iPad using Trawler

JDCAVE said:

... So the dimers on the fixture no longer work?

Jim

Jim, Sent from my iPad using Trawler

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Nope.

LED dimmers are available, but integrating them into the fixtures might be problematic. Also, I've seen LED ads that specify "dimmable". Not sure if that is a marketing word or not.....they might all be dimmable. And finally, as I understand it, LED dimmers might cause RF interference.

By the way, for clarity, the AC wire itself is fine (overkill in fact)...just have to move/jumper the input end of the wire to a suitable 12V source.

Home Depot sells a Cree 40 watt LED 110 volt AC bulb for $9.97 that is dimmable. Put 2 in my salon last week. They draw 6 watts.

Ted

O C Diver said:

Home Depot sells a Cree 40 watt LED 110 volt AC bulb for $9.97 that is dimmable. Put 2 in my salon last week. They draw 6 watts.

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Running an alternator to generate 12 volts DC to charge a battery which is then sent to an inverter to convert it to 120 volts AC to operate a light is pretty inefficient. Installing 12 volt lamps is more efficient.

Marine stores and catalogs are full of LED replacement bulbs and complete fixtures. If you really like your lamps you can rewire them and install the proper sockets.

By the way, for clarity, the AC wire itself is fine (overkill in fact)...just have to move/jumper the input end of the wire to a suitable 12V source.

Click to expand...

Current flows equally well in a conductor regardless of the color of the insulation, but considering that black is the normal AC "hot" conductor while in older boats, it is the DC negative, I think it would be really important to either replace the wires or use colored tape at all junctions to avoid confusion and possible injury.

WesK said:

Running an alternator to generate 12 volts DC to charge a battery which is then sent to an inverter to convert it to 120 volts AC to operate a light is pretty inefficient. Installing 12 volt lamps is more efficient.

Marine stores and catalogs are full of LED replacement bulbs and complete fixtures. If you really like your lamps you can rewire them and install the proper sockets.



Current flows equally well in a conductor regardless of the color of the insulation, but considering that black is the normal AC "hot" conductor while in older boats, it is the DC negative, I think it would be really important to either replace the wires or use colored tape at all junctions to avoid confusion and possible injury.

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The LEDs that I have installed were polarized.

WesK said:

Running an alternator to generate 12 volts DC to charge a battery which is then sent to an inverter to convert it to 120 volts AC to operate a light is pretty inefficient. Installing 12 volt lamps is more efficient.

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Installing 12 volt lighting doesn't eliminate running the alternator to charge the battery. Most modern inverters use less than 1 amp 12 volt DC in the stand by mode and are 90 to 95% efficient in energy conversion, at least that's what my Magnum Energy is.

Ted

WesK said:

Running an alternator to generate 12 volts DC to charge a battery which is then sent to an inverter to convert it to 120 volts AC to operate a light is pretty inefficient. Installing 12 volt lamps is more efficient.

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Why not cut out all the middlemen and use mantle type oil lamps?

Perhaps a simple switch replacement would be simplest.

Run 1 ,2 , or all 3 LED units as your choice for output.

OTS

I think I am going to leave it as is for now. I'm in the process of replacing all the DC lights with LEDs. It is time to replace the house bank. I'm going to work on venting the heat from the radiator coils on the fridge and freezer units and insulate the doors of these units. This combination of changes should reduce the load on the house bank. Changes to the saloon lights will have to wait for a bit

Jim, Sent from my iPad using Trawler

I found replacement LEDs on Amazon for every type of bulb base on the boat, including those halogens that were in my spreaders.
I then jsut changed the source of my lamps form 120v to 12v adn kept all the switches.
As said above, not all LEDs are dimmable, but just yesteday, I ordered a $10 dimmer for LEDs

A strip with 120 LEDS/meter that we cut and conected at 12 DC works very well and is very cheap. $23 direct from China at Alibaba.com

Why not cut out all the middlemen and use mantle type oil lamps?

Heat output into the boat .

Have been buying quite a few LEDs from Hero LED in China. Very happy with the quality and generally about half the price of USA on line sources. They also have base adapters that allow you to adapt fixtures such as what the OP was showing, to G4 bulbs.

Ted

Alemao said:

A strip with 120 LEDS/meter that we cut and conected at 12 DC works very well and is very cheap. $23 direct from China at Alibaba.com

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I just cant get used to these southern hemisphere pictures.