Hacking a Reef Brite

[jimsflies]

http://premiumaquatics.com/prodimages/reefbrite/reefbriteledsMINI.jpg I recently got two of these Reef Brite mini fixtures. I would like to retrofit them to dim and control the dimming with an apex if possible. I also want to consolidate from two power adapters to one plug for both fixtures. I assume this is possible? What would I need to make it happen?










.

[cherrycorals]

Does the Apex have any low voltage control modules?

[jimsflies]

Yes, I think it's built in.

[evilc66]

Reefbrites have typically been dimmable from the power supply, which is variable voltage. I'm sure the Mini's use a similar driver, so it might be simple if the Apex can support something like that. Another option would be to see what is driving the LEDs in each unit, and see if the driver is dimmable from an outside signal.

[jimsflies]

The power supply appears to be a fixed voltage ac/dc power adapter. Sounds like maybe taking one apart and posting more info/pics would be helpful?

[evilc66]

Wouldn't hurt. If you can give me a good hi-res shot of the driver board, I might be able to tell you how to tweak it for dimming.

[jimsflies]

I finally got around to looking at this again the other day. I opened the case rand what I found looks like just two leds that seemed to have silicone holding them and the reflector in place. (The leds were mounted to small boards...but there wasn't anything else inside the case.) Each of my reef brites has two leds which appear to be wired in series.

I'm guessing that the two reef brights could be wired externally into some sort of dimmer(?) and then wired to a single power supply?

[evilc66]

Not quite. If there is no driver internal to the fixture (the ones I have seen did, but they may have been prototypes), then you will need to use an LED driver to run them. For the small 2 LED units, you could use something as simple as a 700mA dimmable Buckpuck and a small 12v power supply and run the two units in parallel off the driver.

[jimsflies]

I'm not sure what a driver looks like...but all I see are what looks like the circuit board with leds mounted to it and glued to the metal reflector. Do all LEDs require a driver?

Where is a good place to get the dimmable buck puck? I assume I could use one of the existing 12v power adaptors to power it? Then it has a lead that would plug into the variable output connection on the apex?

[XSiVE]

Where is a good place to get the dimmable buck puck? I assume I could use one of the existing 12v power adaptors to power it? Then it has a lead that would plug into the variable output connection on the apex?

http://ledsupply.com/03023-d-e-500.php

The buckpuck accepts 0-5v as a dimming source, but it's inverted, so 0v=full blast, 5v=off, you would have to program around that little speedbump with the apex by essentially setting it up backward :big_grin:

[evilc66]

I'm not sure what a driver looks like...but all I see are what looks like the circuit board with leds mounted to it and glued to the metal reflector. Do all LEDs require a driver?

Where is a good place to get the dimmable buck puck? I assume I could use one of the existing 12v power adaptors to power it? Then it has a lead that would plug into the variable output connection on the apex?
You may be able to use the existing power supplies, providing they are constant voltage (most likely are). Can you read off the details on the power supply?

And yes, all LEDs require a driver. Ideally, they need to be kept at a constant current, and have the voltage adjusted based on the needs of the LED. True constant current LED drivers do exactly this. It makes sure that the LEDs have a long life (provided that temperatures are kept in check).


http://ledsupply.com/03023-d-e-500.php

The buckpuck accepts 0-5v as a dimming source, but it's inverted, so 0v=full blast, 5v=off, you would have to program around that little speedbump with the apex by essentially setting it up backward :big_grin:
True, but you need to be careful. The Buckpuck won't like a full 10v going to the input pin. This is easy to fix though. Just put a pair of 100K resistors in series across the 1-10v output channel of the Apex, and conect the CTRL line of the Buckpuck to the point between the two resistors. This is a basic voltage divider, and will halve the voltage to a more Buckpuck friendly 5v.

[jimsflies]

Well there must be more (i.e., a driver) mounted with those leds inside the reefbrite. I probably just don't know what I am looking at. Assuming this is the case will the buckpuck still work?

[XSiVE]

True, but you need to be careful. The Buckpuck won't like a full 10v going to the input pin. This is easy to fix though. Just put a pair of 100K resistors in series across the 1-10v output channel of the Apex, and conect the CTRL line of the Buckpuck to the point between the two resistors. This is a basic voltage divider, and will halve the voltage to a more Buckpuck friendly 5v.

Thanks Clive, I knew there was a safer way to do it! :) Though he'd still need to do a reverse ramp from the apex, Im not sure how well it can accomplish that but it's worth a shot.

[evilc66]

Well there must be more (i.e., a driver) mounted with those leds inside the reefbrite. I probably just don't know what I am looking at. Assuming this is the case will the buckpuck still work?

Not having taken one of those particular units apart, I can't say for sure, but it shouldn't be hard to make a Buckpuck work. Care to take a few shots of the unit disassembled? I should be able to identify all the parts easily then.


Thanks Clive, I knew there was a safer way to do it! :) Though he'd still need to do a reverse ramp from the apex, Im not sure how well it can accomplish that but it's worth a shot.

Yeah, I'm not sure on the programming on the Apex. Easiest way is to just reverse the on and off times. That's how we do it with the Reefkeepers. Say you want the lights to come on at 10am and off at 8pm, with an hour ramp. Set the on time to 7pm, and the off time to 9am. Sounds odd, but it works pretty well.

[jimsflies]

I'll see what I can get for pics. The unit doesn't come apart very easily as the reflector is siliconed to the led which is glued to the housing/heat sink.