I really love the fact that I can have ground everywhere. For soldering bridges to connectors I have no problem, I am using a thicker type of solder and although they come very close to the ground dots they never short-circuit but I found out that the solder Flux sometimes leaks some current wich is easily solved by cleaning with Isopropyl alcohol. I'm hoping to get a new delivery of this boards soon.
Seller is very responsive to all questions regarding the items purchased. Took it a step further and configured the board for me, eliminating the need for soldering in the resistor. Very nice to deal with and would have no problems ordering again if the need arises.
Aug. 10, 2016
Upgraded a mixing board needing 3 voltages to run off 12V
These little guys handle a good load, and are fairly easy to use. They come with 3 surface mount resistors set for 3.3V output. Depending on how the leads are attached you get either +3.3V or -3.3V.
The docs describe changing R1 / R2 in order to get different voltages, but I recommend instead bridging across the existing 10K resistor R3 to lower its resistance. I needed a couple voltages for my project, so used 2 modules. By bridging a 5.1K resistor over R3 it ends up being 3.38K, which gives pretty close to 5V. That positive converter runs very efficient -- really cool while delivering about 700ma. In another module I needed -12V, which I got by bridging a 1K resistor over R3 to end up with 909Ω. This negative-side converter got much warmer, even though it was only delivering about 500ma. So for giving negative voltages perhaps it's not quite as efficient, but still it never gets hot to the touch. Only warm.
One reason I really recommend to bridge resistors on R3 is if any added-on resistors ever fall off, the supply just reverts to a lower voltage instead of snapping to a higher one. So less chance of damaging things. Also in order to mess with Rfb1 / Rfb2 you'd have to remove the existing resistors. So I find it much easier to just play with R3.
The actual soldering of the resistors was really fiddly, since the surface mount resistors are REALLY small. I ended up leaving them in place, and soldering between pins 5 and 7 on the IC. Pin 5 (VSENSE) is on the corner of the chip, and very easy to get to. And really instead of pin 7 (just GND) then there's a nearby capacitor and resistor hanging on ground that you can solder onto. I've got a fairly big iron, and this was about the easiest for me to mess with.
Perhaps evident, but just so everyone is aware -- the converter doesn't boost, it only lowers voltages. And it does it pretty well.
July 8, 2016
Seller responds and resolves shipping issue, no product yet.
Shipping problem seemed to have been with the carrier, seller reshipped ordered items via Priority Mail. The charge will not be disputed and communications have improved dramatically. I really like the product and look forward to using it in my circuit design. Your review system forces you to grade each of the four categories even if one does not apply, you need a "n/a" option. If the ground plane board is as specified, you can bet I will grade it 5 stars. Hope to receive items on 7/12/16, will post another update after using the product.
Response from SpeedyLab | July 8, 2016
We are very sorry for the issue about the shipping. The package has been dropped at USPS but the tracking info failed to update, and USPS did not give a timely response about the issue.
You are welcome to dispute the charge. I will send you a new package for free, so that you get a chance to see that our communication is probably bad at this moment, but the product is not one star :)
Thanks for the feedback. We'll improve and do a better job in the future.