nfeuerhelm
- #1
I started this a little later than I should. I haven't been around the forum much for a couple years now, but I thought I would share the mod I'm working on for my LED hood.
I have had this hood for over three years now, and I must say that it works great (or worked great). My current tank doesn't have a cover, so any splashes or water at all would end up on the hood. With regular cleaning this wasn't an issue for over two years, but at about two and a half years corrosion inside the threeway switch (to switch between day light, moon light, and off) and power connector began to affect performance. I took the hood apart and cleaned out what corrosion I could, and it worked fine for another three months or so. That brings us up to about three months ago. Since then, I've been making due with a strip florescent over the tank while I've been figuring out this mod and waiting to have some free time.
While planning what to do to fix the hood, I started by thinking about what I disliked about it. I really like the moon light feature, but they are nearly impossible to use if the hood is attached to a standard 120v passthrough timer. This is all I really have to say bad about the hood. This is where I started thinking about how to fix this. First, the way this particular hood works is that there is a big circuit board covered in white LEDs, blue LEDs, and resistors. Coming off this board there are three leads - one common ground, one lead that lights up all the LEDs, and one lead that only lights up the blue LEDs. The switch controls which lead the power goes to for day light or moon light. I could get into more technical detail on the circuit, but I don't want to bore anyone. So the first issue here for controlling this is that two different timers would be needed to control the LEDs. The second is that the LEDs need 12v DC, while most timers available at hardware stores, LFS, etc. are only for 120v AC. If you were to use these AC timers, two separate power supplied would be needed for the board. That didn't seem like a good option to me, so I went in search of 12v DC timers. It took a while, and I toyed with the idea of building a custom timing circuit, but I found these on Amazon. These will allow me to use two of these timers to control the the two lighting circuits. I actually ended up getting three of these timers and a project box to house them in. I only need two for the hood, but I am planning to move to a 45gallon tank soon and will likely be adding more lighting. I will explain that more later.
How I am setting this system up is to use the original power supply to go into the project box to power the timer and then go out to the hood. The timers basically act as switches, but need to be powered for the electronics. I am still waiting on delivery of the timers and box. I am using standard DC power jacks and plugs, but it gets tricky again when trying to get three leads from the box to the hood. Most DC power connectors are designed for two leads. To solve this I spec'd out some professional quality 3.5mm TRS connectors, these are type of connectors used on mp3 players and headphones. Most of these aren't rated for the 500mA that the power supply puts out, but I was able to find cables and connectors rated up to 1A at a local electronics component store, but have to wait for them to come back in stock. From here the next issue was the two holes left in the side of the hood and how to mount the 3.5mm TRS jack. I am lucky enough to have a local 3D printing shop near me, so I was able to get a cover for the switch hole printed that I will be mounting the jack in. Because of the size, and the time I walked into the shop, I was able to get them to print the cover I designed for free. Only downside to that is I had to settle for orange plastic. I then used a 1/4-20 machine screw, rubber washer, and locking nut to seal off the power connector hole in the hood. I have added a picture of this.

I will add more as this progress, and I will be happy to answer any questions that anyone has.
I have had this hood for over three years now, and I must say that it works great (or worked great). My current tank doesn't have a cover, so any splashes or water at all would end up on the hood. With regular cleaning this wasn't an issue for over two years, but at about two and a half years corrosion inside the threeway switch (to switch between day light, moon light, and off) and power connector began to affect performance. I took the hood apart and cleaned out what corrosion I could, and it worked fine for another three months or so. That brings us up to about three months ago. Since then, I've been making due with a strip florescent over the tank while I've been figuring out this mod and waiting to have some free time.
While planning what to do to fix the hood, I started by thinking about what I disliked about it. I really like the moon light feature, but they are nearly impossible to use if the hood is attached to a standard 120v passthrough timer. This is all I really have to say bad about the hood. This is where I started thinking about how to fix this. First, the way this particular hood works is that there is a big circuit board covered in white LEDs, blue LEDs, and resistors. Coming off this board there are three leads - one common ground, one lead that lights up all the LEDs, and one lead that only lights up the blue LEDs. The switch controls which lead the power goes to for day light or moon light. I could get into more technical detail on the circuit, but I don't want to bore anyone. So the first issue here for controlling this is that two different timers would be needed to control the LEDs. The second is that the LEDs need 12v DC, while most timers available at hardware stores, LFS, etc. are only for 120v AC. If you were to use these AC timers, two separate power supplied would be needed for the board. That didn't seem like a good option to me, so I went in search of 12v DC timers. It took a while, and I toyed with the idea of building a custom timing circuit, but I found these on Amazon. These will allow me to use two of these timers to control the the two lighting circuits. I actually ended up getting three of these timers and a project box to house them in. I only need two for the hood, but I am planning to move to a 45gallon tank soon and will likely be adding more lighting. I will explain that more later.
How I am setting this system up is to use the original power supply to go into the project box to power the timer and then go out to the hood. The timers basically act as switches, but need to be powered for the electronics. I am still waiting on delivery of the timers and box. I am using standard DC power jacks and plugs, but it gets tricky again when trying to get three leads from the box to the hood. Most DC power connectors are designed for two leads. To solve this I spec'd out some professional quality 3.5mm TRS connectors, these are type of connectors used on mp3 players and headphones. Most of these aren't rated for the 500mA that the power supply puts out, but I was able to find cables and connectors rated up to 1A at a local electronics component store, but have to wait for them to come back in stock. From here the next issue was the two holes left in the side of the hood and how to mount the 3.5mm TRS jack. I am lucky enough to have a local 3D printing shop near me, so I was able to get a cover for the switch hole printed that I will be mounting the jack in. Because of the size, and the time I walked into the shop, I was able to get them to print the cover I designed for free. Only downside to that is I had to settle for orange plastic. I then used a 1/4-20 machine screw, rubber washer, and locking nut to seal off the power connector hole in the hood. I have added a picture of this.

I will add more as this progress, and I will be happy to answer any questions that anyone has.