While designing a project that required 5v USB power ports from a much higher voltage source (eg. 12v or 24v), it occurred to me that there are circuits already designed to do this. In fact, not only do they exist as low-cost, easy-to-purchase modules, but some of them already have the USB port soldered onto the board.
Four Step-down converters with USB ports were picked out and reviewed in an attempt to find “the best cheap USB switch-mode step-down converter” for 12v power supplies.
Continue reading A review of four Switch-mode Buck (Step-down) converters with USB ports
With the current DIY/Maker movement in full swing, one thing that almost all of us need is a good Multi-meter. When shopping for one, it was decided right away that a good entry-level multimeter for beginners had to be:
- under $50
Why these 3 criteria?
Digital for high precision, Auto-ranging to eliminate the need to switch the dial every time something changed, and $50 maximum to keep this within the budget of most DIY’ers/Makers like you and me. (As an aside, the requirement for an Auto-ranging feature also makes the minimum around $20.)
After perusing Amazon, it was discovered that 8 models fit this criteria. The biggest problem was that all 8 of them reviewed really well typically averaging between 4.4 and 4.7 stars.
The customer reviews were okay for getting a feel of each model, but they were so inconsistent that there was no way to compare and contrast one model with the next. So one of each was purchased and immediately we began the going over of the models while poking and prodding each one.
Continue reading Best beginner’s auto-ranging Digital Multimeters (DMMs) compared and reviewed
The USB port is one of those things in the 21st century that provides the necessary “lifeblood” (electricity) to charge and re-charge all of our fancy cellphones and gadgets. Yet rarely in this process is there a good way to know that things are going well in the power transfer process. Maybe you’ve experienced plugging in your phone to charge and yet for some reason it doesn’t appear to take a charge or perhaps it’s just charging too slowly. And how does one figure out what to do about this? Surely, there is a little gizmo that can help us out here!
And sure enough, there is. In fact, there’s more than just one. There’s a whole bunch of them. They go by the names “charger doctor”, “USB detector”, “USB meter”, and even “USB power monitor”. At the end of the day, they’re mostly just digital multimeters designed for the USB port, but what they do is insightful!
And the best part is that they sell for under $15.
Continue reading The portable LED USB multimeter (that you didn’t know you needed)