Introduction: Hardwired USB Charger
So I have a situation where I need to mount a wireless camera. The camera is powered by a USB 5v, 1000mA charger, which is supplied with the camera when purchased.
My dilemma is I DON'T have an outlet where I am mounting the camera. However I DO have nearby a old light fixture about 8 ft high on a 10 ft wall. I am no longer using the fixture (an electrical sconce fixture). So I will remove the sconce, and hardwire the USB charger to 120 volt power located behind the light fixture. I want to keep this as clean as possible, and I don't want to install an outlet on the wall.
I did this because I could justify some risks. For example, I know I will likely risk voiding any warranty with my little USB charger, and if the manufacture knew I was hardwiring their USB charger to power my camera, they may void the warranty of the camera too. I'm willing to take these risks.
Other risk: Electrical fire is always a risk, even in the most ideal situations. Did you know you can cause a fire by charging your cell phone (you've heard stories, right?. Sure the batteries are what normally cause the fire, but USB chargers fail too. They can cause a fire. That's why many phone manufactures don't recommend you charge your phone by your bed. This is all rare, but possible.)
In any case, I don't believe for a moment that will happen to me with the charger, in the manner in which I am doing this. How can say that? Because I am enclosing the final project (what you see pictured) in covered, metal electrical box. THAT will eliminate the risk of fire of the USB charger in my case. Could I do this WITHOUT enclosing the charger? Sure, but I don't think it is wise.
Disclaimer: This is how I did this project. I'm not suggesting you do it. However if you DO choose to duplicate this project, please do it at your own risk. Electrical work is inherently dangerous. Please do NOT attempt this project if you cannot do it safely.
So if you want to how I accomplished this...read on.
Step 1: Supplies
- The charger of course
- Mini torch or soldering iron
- Wire (I'm using 18 gauge rated for up to 5 amps, even though I won't come near drawing this.)
- Wire strippers
- Helping hand (optional)
Step 2: Prep
I filed the two leads first.
I cut shrink tubing to size and had it ready.
Step 3: Solder
I can't photograph and solder the wires onto the leads at the same time, but this is pretty straight forward.
I threaded the stripped wire through the hole for some added strength.
I used flux. I didn't pre-tin.
Since I used a torch, I needed to work FAST. I did NOT want to overheat the leads and risk melting the casing of the USB charger. If I was in doubt, I could have used an soldering iron to play it safe. (But I could have overheated the leads with the iron too.)
Step 4: Shrink Tubing
After I my soldered wires cooled, I "shrinked" on some tubing for each lead, I put on an additional piece of tubing as shown on the wires. I did this because I had split the lamp chord and wanted it to be brought back together for a little added strength and stability.
I used thin wall tubing rated to 600v.
Step 5: Final
I can now safely hardwire it to a 120v source. There is no polarity on the charger (at least on my USB charger there isn't) so I'm not worried about which lead goes to the hot wire (the black wire) or neutral (the white wire).
Again, I am keeping the charger in an approved covered enclosure, one big enough to dissipate heat. Chargers do get warm, but I've never had one get so hot that it would melt plastic. I first mocked this up and tested it out for a day to monitor it. My wireless camera doesn't have much of a draw, so I'm not concerned about heat at all.
Feel free to share your thoughts and comments.