LED lighting

[Irving]

Here is the coat closet that is not part of the other major lighting. It's always been very annoying that there is no light in here, especially in the winter when it gets dark early and we actually need coats. I'm waiting for my magnetic door switch in the mail. This is just a single run of warm white LEDs running on a 12v 30 watt power supply. It's the perfect amount of light for a barely used closet.



Here is the product list in case anyone is interested.

LEDs: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Power supply: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
90 degree connectors: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Door switch: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Tape: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I installed an outlet into the closet to plug into, and I already had a power cord to use with the power supply. I had some similar tape from other LEDs that I used under my cabinets, but I have this roll coming for future stuff. The 90 degree connectors aren't necessary, but they are a lot easier than soldering, especially if you start messing with colors. Also I ran the strip from about 6" off the floor on either side of the door, and across the top and only had about 9" of LED left of that 16.4" roll.

[00tec]

You are going to want a small project box or something. That magnetic switch will only handle 1/2 amp or so, which is why it has a relay. You'll want to hide the relay somewhere.

Guess you could use a pop-in wall box and a blank or coax plate to hide it, but that is probably against fire code.

EDIT: the description on that item is a bit confusing. It says "what's in the box: Prewired 20-amp/10-amp Mini Relay Assembly". I have never seen a simple magnetic reed switch over 1 amp.

My magnetic switch worked about 4 times, then stuck and melted using about 9ft of LED strip.

[Irving]

Hmmmm. The reviews on that switch pretty much say that it works great, then dies really quickly. I assume that's from people not using it with a relay? I didn't use a relay, and had the same experience a few years ago on my pantry light. I recently tried it again and it seems to be working fine. Having had that experience, I tried searching online for a more robust switch, but could not find one. If anyone has a lead on something better, I'm all ears. On my pantry I had a pressure switch that I repurposed from an old refrigerator, but it looked crappy and I could never get it to stay in place.

With all that said, can you link me to an appropriate relay switch? For the closet (and pantry) I'd probably just stick on the wall since no one will ever see them. I think I actually have a few 12v relays in my tool box, so I may already have one.

[00tec]

Hmmmm. The reviews on that switch pretty much say that it works great, then dies really quickly. I assume that's from people not using it with a relay? I didn't use a relay, and had the same experience a few years ago on my pantry light. I recently tried it again and it seems to be working fine. Having had that experience, I tried searching online for a more robust switch, but could not find one. If anyone has a lead on something better, I'm all ears. On my pantry I had a pressure switch that I repurposed from an old refrigerator, but it looked crappy and I could never get it to stay in place.

With all that said, can you link me to an appropriate relay switch? For the closet (and pantry) I'd probably just stick on the wall since no one will ever see them. I think I actually have a few 12v relays in my tool box, so I may already have one.

I remember discussing your pantry. It was about the same time I was working on my LED lit truck toolbox. My reed switch from radio shack had the "." worn off of the packaging. I figured I was good, until it stuck and almost caught fire. It worked great, enough to take a couple pics. After adding the relay in circuit, all was fine.

As far as I know, due to the nature of the switch, it isn't currently possible to get more amperage through them. Simple solution is to switch the 12v side of that supply, then relay the bulk of the power of that supply to the strip. It can be done out in the open, but you would have a significant amount of wires showing.

You could stuff the relay and relevant wire in a 2x4 project box and screw to the wall, or stuff it into a pop-in (post build) box and use a modified blank plate or a coax plate to hide it.

And yes, the relay I used and am describing is the same 4 or 5 pin Bosch automotive relay you likely have laying around.

[Irving]

So power supply --> relay --> switch?

Usually when I wire a switch into low voltage DC I put the switch on the negative cable, can I still do that with the relay?

[CobaltSkink]

I have used this motion detector. I think it is also available in white.
There are two little potentiometers inside to adjust sensitivity and the time it stays on (IIRC).
I open them up, figure out where the pots are, and drill access holes in the back of the case.
In my safe, they are zip-tied to square zip-tie anchors. You could also use double-sided tape to mount them.
https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1

[00tec]

So power supply --> relay --> switch?

Usually when I wire a switch into low voltage DC I put the switch on the negative cable, can I still do that with the relay?

Yes, but you will need both + and - at the relay to make it function.
Using this as a diagram (ignore their notes)


To switch using the negative wire:
Run your + from the power supply directly to the LED strip AND pin 86 on the relay.
Run your - from the power supply to the reed switch AND pin 87 of the relay
Run a wire from the reed switch (the NO or normally open contact) to pin 85 of the relay
Run a wire from pin 30 of the relay to the - on your LED strip.

This way, your reed switch only sees the power needed to switch the relay on and off (not much), while the relay handles the full power that the strip draws.

[Irving]

Perfect, thanks.

[Irving]

These are the relays I have. The 30 pin and 86 pin locations are in opposite positions. Am I correct to assume that I can simply follow your instructions by the numbers to wire them both correctly?

[00tec]

These are the relays I have. The 30 pin and 86 pin locations are in opposite positions. Am I correct to assume that I can simply follow your instructions by the numbers to wire them both correctly?

Looks like the one on the left is exactly as I assumed, so that one is good.

Right one, i would need to see a bit more on. There may be a diagram on the top...

Edit: if you want to drive a few miles, I can produce a couple of relays with plugs and pigtails. Will be around 15 miles east of you this weekend.