I’m a huge fan of Big Clive, and watch his videos regularly. Back in December he built a DIY LED bulb kit from China, and as soon as I finished the video I ordered a couple for myself! It’s a fairly simple kit with a lot of potential for customization. There’s a lot of solder joints but the overall assembly isn’t too complicated, and the theory behind how they work is fascinating and not too hard to comprehend. Best of all, with prices well below $2 shipped, they’re cheap fun! I recently assembled one of these kits so I can review it and share what I’ve learned so far.
This little LED test box couldn’t be simpler – pop an LED into the tester, push the button, and see it light up. The top header accommodates standard LEDs with two leads, and the bottom headers accommodate 4-pin “piranha” LEDs. I use it frequently when assembling LED lighting projects or to quickly test a new batch of LEDs. It’s a great value for the approximately $2.00 USD that I paid for it. With that said it has some issues, and there are a few things to be aware of when using these testers.
You can’t expect much for $2, but the quality is fine for the price. The biggest issue I have is the headers; they don’t always make good contact with the leads on the LEDs, especially the bottom rows for piranha LEDs. So sometimes I have to fiddle around with the LEDs to get solid contact. The other minor issue is the battery compartment, it’s fairly tight and I’ve had some trouble figuring out how to best orient the battery so it will fit with the case closed. With a little trial and error though, it’s possible.
These are minor quibbles, and acceptable given the price. But there are some more concerning issues with the circuit itself, which I’ll cover in the next couple sections.
This was a random find on Ebay, just something I came across while looking for something else. I really liked the look of it, and I needed something that could measure large currents anyways, so I bought it. I have a Sparkfun digital multimeter, which is a steal at $15 and serves most of my needs as a hobbyist, but it’s best used for low current measurements, under 200ma. It can do up to 10 amps, but only for 10 seconds. It’s a useful feature, but sometimes I want to watch a circuit’s current for an extended period of time. I don’t want to buy an expensive DMM when the Sparkfun unit serves 98% of my needs, so an analog ammeter seemed like a good compromise. It may not be as accurate as a DMM, but it’s good enough for my needs.
I don’t know much about the meter, other than it was made by a company called Stansi located in Chicago, and it has three ranges of measurement: 0-1.5 amps, 0-3 amps and 0-30 amps. After receiving the meter, I tried it out, and found that the measurements it was giving all seemed to be significantly off. I was disappointed; I liked the look of it, but I didn’t buy it to be an antique, I bought it to actually use! I noticed that the connections on the underside of the meter were all corroded quite a bit, so I took all of the connections apart, cleaned all of the posts, washers, nuts and other bits and pieces with steel wool, and put everything back together. After testing it some more, it seems that all it needed was a good cleaning, the measurements are all very close now when compared to the DMM. Success!
If you’re hobbyist like me, and need to measure large currents but don’t want to spend the money on an expensive DMM that you don’t really need, then an analog ammeter may be the solution. A digital display certainly has significant advantages in terms of speed an accuracy, but if you buy a large meter, it should be easy to get a “close enough” measurement. In the photo to the left you can see the Stansi meter connected to a BigClive.com RGB controller, and it’s clear that it’s pulling approximately 320ma of current. It may not be as quick or accurate as a DMM, but there’s something about watching that needle bounce around that an LCD display can’t replicate, and for $20 and an hour of my time, it’s a good value. I expect to get lots of use out of this meter.
I recently reviewed the Color Night Joule Thief by The LED Artist, and tonight I built the original Night Joule Thief. It works just like the color version, except that it uses two white LEDs instead of a single color-changing LED, and has slightly fewer components. Unlike the color version, I didn’t run into any problem with the PCB layout; everything fit with no risk of any short circuits. Assembly is easy and well-suited for a beginner.
Light output is very good using a fairly new battery. I tried it in my bedroom and it provides enough light to keep me from stubbing my toes on the bed posts after dark. With that said though, I wish the output was spread out more, it’s very narrowly focused. This could be adjusted to some degree by soldering the LEDs so they point at different angles. Another possible solution is using LEDs with a wider output beam. I purchased two kits, so I may try doing something like this with the other. Other possible modifications which are discussed on the related Instructables page include using a switch instead of a photoresistor to turn the LEDs on and off, and using alternative battery clips to allow for C, D and other size 1.5v batteries.
Overall, this is an excellent kit, perfect for beginning electronics enthusiasts learning to solder as well as experienced hobbyists looking for a simple circuit to build that offers some room for customization. It’s available for under $11 from The LED Artist.
I recently stumbled upon Akimitsu Sadoi’s website, The LED Artist. Akimitsu describes himself as a Brooklyn, NY based electronic artist with the motto “Art and Technology are Friends”. He designs and builds LED Art projects and offers a variety of kits for sale through his online store. I’m a sucker for anything that lights up, so it didn’t take me long to find several kits I wanted to purchase and build. I can’t afford to buy every kit I want on there, but I did pick up a couple, the smaller (and cheaper) of which is the Colour Night Joule Thief.