Incorporating pool lights

Iain

Apprentice elf
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Nov 13, 2018
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Darwin
Hi all,

next year will be my first year doing a display on my house instead of parts for someone else!

Coincidentally my pool lights have been busted for a few years and I’ve never had the inclination to fix them. I think they would give a great depth to the display so it doesn’t look so harsh and outlined.

I don’t want to rewire the 2-core cables underground, which means I would have to stick with white LED lights in the pool fitting, and maybe use a DMX LED dimmer on the post? i.e. I would send a varying voltage to brighten or dim the white light at the end of the cable, much like a dimmer switch in your house.

Can anyone suggest an LED dimmer/controller for this? Is there anything “smart pixel” ready or would I have to roll my own?

Thanks :)
 

David_AVD

Grandpa Elf
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A DMX controller with DC output would work, but not by varying the voltage as such.

They work by applying PWM to the DC output(s) therefore varying the on/off time ratio.

Hanson Electronics sells such DMX DC controllers as well as pixel signal I/O versions I believe.
 

Iain

Apprentice elf
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Nov 13, 2018
Messages
64
Location
Darwin
Ah of course, forgot about PWM

The 2811DC15 DIMMER looks like it will do the job nicely…

so I think all I add to that is a power supply and any LED that can handle a DC PWM input?

Thanks
 

Iain

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Nov 13, 2018
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Darwin
Can anyone recommend a white dimmable 10-15W LED with a flat back for mounting to a metal plate for heat dissipation?

I pulled one of the pool light fittings out, and the silicon on the attachment to the fibreglass is coming away... So I probably need to drain the pool to fix that.

New lights will cost at least 2x $300, so I'm still going to try and replace my current ones. Unfortunately they're only 2-wire so nothing 3-colour controllable :(

My plan is:
  • new DC power supply
  • Hanson 2811DC15 (only need 2 channels, but oh well)
  • rainproof enclosure for the external pieces
  • some sort of 12V dimmable LED, preferably on 2 pins so I can reuse the existing ceramic mount in the fitting
  • lanolin sealant (the original lights had this pumped into all the screw holes and cable fittings)
This shouldn't cost too much to test out as I can borrow another PS and skip the enclosure for now. Sometime in the dry season I'm going to have to drain the pool...
 

Iain

Apprentice elf
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Nov 13, 2018
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Darwin
Yeah I watched that but he has 3-wire pool lights (looked like they were 120V) and I only have 2 wire... it might be easier just to pull new wires through!
 

Ltmup

Apprentice elf
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Feb 1, 2020
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if you are going to try it drain just before next monsoon comes down, free pool refill
 

Notenoughlights

340,000+ twinkly lights
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Oct 16, 2016
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Christchurch, New Zealand
Wondering if you couldn't get an esp8266 controller down there and connect it via wifi, may be too far away and through too much material ending up with a bad signal however. Use the 2 cores for power.
 

BAZMick

Full time elf
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Nov 26, 2019
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Rob already tried that in the HookUp video. Wifi doesn't work through water unfortunately, bummer!
 

Ltmup

Apprentice elf
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Feb 1, 2020
Messages
86
most installers leave enough cable to pull light out to work on side of pool. if you go the recable route tie a draw string to existing
 

Iain

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Nov 13, 2018
Messages
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Location
Darwin
After reading and watching too much about LEDs and drivers to the the point where I have a headache, I think I'm heading towards this idea:
  • A driverless(?) COB LED of around 15-20W. This is to match the old halogen brightness of around 100W. Most dimmable LEDs come with their own driver and accept a 0-10V dimming input, so they don't work with a PWM input, which is why I chose a COB with no driver
  • A 2811DC15 DIMMER from Hanson Electronics.
  • A 35V power supply. This is so that I can power both the 2811DC15 and the LED with one supply
  • maybe a heatsink, although I'll try and get the heat to transfer to the pool light casing (which is water cooled!)
I know ideally LEDs should be dimmed with current, but I can't find a way of doing that with two wires that integrates to 2811, and there's plenty of examples of people doing it with voltage PWM.

Potential problems:
  • I might need up to 40V to run the LED, so I would need to step-down the voltage to the 2811DC15 somehow
  • it overheats and I let the smoke out
Any advice from LED experts would be appreciated!
 

Iain

Apprentice elf
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Darwin
I don’t know if I could get two wire LEDs bright enough… I need equivalent of a 100W halogen globe in a small space, which is why I was thinking of COB.
 

i13

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Jul 5, 2013
Messages
1,156
You don't need two wire LEDs. You can connect two separate LEDs in the opposite direction across the same two wires. The tradeoff with this option is that there will be a slight strobe. I have not seen it in person but it should be similar to the effect when you wave your hands around in front of an old CRT monitor.
 
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