Introduction: Dog Necklace/harness LED Mod (USB Rechargeable)
So I wanted to grant my tiny dog some extra security while taking a walk during the night.
This is why I came up with the idea to add some lights to the existing harness. I also wanted to save on batteries and decided to use a USB rechargeable power supply.
In the coming chapters I will show you the materials and tools used for this project als well as the techniques applied to realize this extra feature.
Feel free to ask any questions and comment on my 'ible, I will do my besteht to answer in time.
Step 1: Materials
The materials and tools needed for this project are as easy and cheap to get as you can imagine.
First you will need to get some sort of power supply. I decided to use the guts of a small flashlight I hat lying around. It is rechargeable over USB and had a 1W LED installed.
As I wanted the whole harness to light up, I decided to replace the single 1W LED with 10 smaller LEDs. As white LEDs are running at about 3,7V, I calculated the current needed for the LEDs as following:
So the power supply provides 270mA of current. So I went for 10 LEDs of 30mA to get the maximum of power.
The LEDs I got are SMD ones. I needed theese to them on the wire, as you can see on the following steps.
The last thing you will need is some laquered copper wire. It is important to get the wire with the laquering on, as you will most likely short your system, if you use a blank wire.
You can find laquered wire in many electronic parts you have laying around. Basicly any coil has it, wether it is an electric motor, a transformer or an indictive sensor. You don't need a large diameter, I used 0,18mm.
Step 2: Tools
3rd hand comes in quite handy
needle and thread
Step 3: Mount the LEDs
To mount the LEDs you fist have to find out which pins are the anode and cathode. You usually find these informations on the data sheet.
Now solder the LEDs to the wire. I mounted the LED in my 3rd and and applied some solder to the pads needed. Then I pressed the copper wire to the pad and heated it all up with the soldering iron.
Make sure you apply enough heat to burn the laquering of the wire and get a good contact.
Solder all the LEDs in parallel!
Step 4: Sew the LEDs and Power Supply to the Harness
Now sew your project to the harness. I did some stitches around each LED and one over the wire between.
I also sew the power supply onto the harness. Make sure to keep the switch reachable, and the USB ready for recharge!