Thursday, July 11, 2019

More LED Lights

While looking through Amazon for the HybridLight that I reviewed last week, I noticed a variety of tiny LED lights that plug into the ubiquitous USB port. Since I have a spare USB port on my car charger, several portable battery packs for charging my devices, and unused USB ports on my laptop, I thought I'd see how they work as emergency lighting.

I found an assortment pack, three each of four different mini lights, for $13. Since I am an Amazon Prime member the shipping is free, so I added the assortment to an order I was placing anyway. They arrived in a sturdy plastic box which will probably get re-purposed after I figure out where I want to store the individual lights.

Looking at them, you can see how simple LED lighting actually is. There are only three components on the simple ones; power contacts, a resistor, and the LEDs. The resistor is there to knock the 5 Volts supplied by the USB port down to whatever voltage the LEDs use (it varies by type of LED, which is a topic for another time).

There are several other models on Amazon, some as cheap as $0.50 apiece and most costing about $1.00 each. The designs are all similar; some are obviously just rebranded version of what I bought and others are slight variations with fewer or more LEDs. There are also several types of USB powered lights on flexible stems that would be more convenient for direction light where you need it. All of the mini lights have the LEDs on the same side of the board as the power contacts, so you have to move the power source to move the light, which isn't easy if it's plugged into a laptop.

Here's what I got with some specifications and my notes so far.

Clear Plastic Cased (top)
  • 3 LEDs, larger than the others, a bright white light.
  • The brightest of the four, this version looks like a thumb drive with its rounded plastic case and full USB connector. There's even a hole in the case for a lanyard or small ring to attach it to a keyring.
  • Because of the fully encased design, this is the only one I would put in a pocket or pack by itself.
  • Listed as 2.3W, which works out to 460 mA.
  • Quickly got warm, but not hot, to the touch.
  • The only one of the four styles that would stay on when plugged into my HybridLight. Further research found that the circuitry inside the HybridLight and some battery packs will not recognize a load below 100 mA and will shut off power to the port after a short period (23 seconds by my stopwatch).

Black board, Warm White (left)
  • 3 LEDs, a warm, yellow glow
  • Listed at 0.2 W, so 40 mA draw. From a cheap 5000mA battery pack you could expect to run one of these for 125 hours or a little over 5 days continuously.
  • Runs cool to the touch.
  • A hair smaller than the white-boarded style, they do have a hole in the board for attaching it to a keyring or lanyard. I'm not sure how sturdy they are, and I wouldn't trust them bouncing around in a pocket with keys or loose change.

White Board with Touch Sensor (middle)
  • 4 LEDs, a warm yellow-tinted light.
  • Listed at 0.5W, it draws 100 mA. That's 50 hours from one of my little battery packs, and 100 hours from the larger ones. Plugged into a USB charger in a car cigarette lighter, you could light up a stranded car for about three weeks, non-stop, if there were nothing else drawing on the battery.
  • The touch sensor works with no pressure, just the contact of bare skin on a conductive pad on the back of the board.
  • Bright enough to cast sharp shadows in a small, dark room.
  • Small. At about a half-inch wide and an inch and a quarter long, these would be easy to lose in a pocket.

Black Board, “Positive White” (right)
  • The same as the one on the left, but with different LEDs installed. You can barely see a difference in the color of the LEDs, and there are no markings or other clues to tel you which is which.
  • The light is a lot more white and seems a bit brighter than the other black boarded type.
  • Bright enough that you don't want to look straight at it.

Simple, cheap, small, and they work.

You may wonder why I place so much emphasis on lights in my choice of products to review. I have a family member with severe anxiety issues. Total darkness and silence are two of the big triggers for that anxiety, so I do what I can to eliminate those before they become a burden in a time when I have other things to worry about.


  1. Pastor Tim,
    The last comments about dealing with a person with anxiety issues, was perhaps the best comment I have heard in quite awhile. Because it implies that everyone has their own issues that they must deal with, and what is the most important thing for one, like having a ton of ammo, might be a mile down the list for another.
    I know it probably was not meant as such an important thing, but it just struck me that way. My wife has difficulty walking long distances, and so having a wheelchair that can go over difficult ground is an important thing for us to have available. For others, it might be glucose tabs, or whatever. Great post, on it's own merits, but also by what it implied as well.

  2. Just want to point out an important error in the explanation of the LED circuit. The purpose of the resistor is to limit the current through the LED and has little effect on the voltage across the LED.


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