标签: player

This is a funny old world and no mistake. I was sitting in the Pleasure Dome (my office) happily beavering away when someone dropped a package on my desk. When I opened this unexpected container, I discovered an SP-5000 Solar Media Player from the folks at Secur Products .     This little rascal is actually rather interesting. First of all we have a rainproof (water-resistant), dustproof, shockproof case for a smartphone. Although you can't see it in my photo above, there's a reasonably rugged carabiner on the back that allows you to attach the case to your belt or backpack or whatever.   The case also boasts a 5.5V / 70mA solar panel and two 3-watt stereo speakers, which don’t sound half bad. When you open the case, you discover a container for your smartphone along with a wealth of cables and connectors. What you can’t see in this image is a 2000mAh power bank, which is mounted in the lid.     In the upper-right-hand corner of the above picture we see two cables coming out of the lid. One of these ends in a standard male stereo plug. If you want to use the SP-5000 as a media player, you simply plug this into your smartphone or MP3 player -- I used my trusty iPad.   The other cable terminates in a female power plug, which acts as DC-in if you are charging the power bank from a PC or a wall-mounted supply, or as DC-out if you are using the power bank to charge your smartphone or similar device.   In the lower-left of the above picture we see a USB-to-power cable, which can be used to charge the power bank from a PC or a wall-mounted supply. Alternatively, you can use the solar panel on the front of the case.   In the lower-right-hand corner of the above picture we see four connectors that plug into the DC-out connector and that can subsequently be used to charge your smartphone or whatever. From right-to-left we have a 30-way iPhone connector, a micro USB connector, an 8-pin Lightning connector, and a female USB 2.0 connector.   The cable that puzzles me is shown on the left. This is a male USB 2.0 connector (which could be plugged into the female USB connector we just discussed) feeding a 30-way iPhone connector, an 8-pin lightning connector, and a micro USB connector. The only use I can see for this is to provide a 9" extension cable for charging purposes, which seems a little over-enthusiastic. Personally, I would have omitted this cable and replaced it with a DC-to-mini USB connector, but what do I know?     One thing that always bugs me is when you purchase something like a solar media player and subsequently discover that you don’t have the right connector. In the case of the SP-5000, you are provided with a cornucopia of these little scamps.   Last, but not least, the SP-5000 offers a safe and snug haven for most MP3 players and smartphones, including an iPhone 6 and a Samsung Galaxy S5.   The reason I commenced this column by saying "This is a funny old world" is that I'm one of the few people left on the planet who doesn’t actually own a smartphone. About 12 to 18 months ago, I came to the realization that nobody ever called me with a message I wanted to hear, so I stopped carrying one and I've been happier and less stressed ever since.   Having said this, one thing I've been ruminating on is that it might be handy to have a smartphone for use in navigation and also if any unexpected problems arise.   As part of my ponderings, I've been oscillating back and forth between an iPhone 6 and an iPhone 6 Plus, but the iPhone 6 Plus wouldn’t fit in my SP-5000 case, and there's no point in being in possession of a case like this if you also have a smartphone that won’t fit in it. So, the end result is that the folks at Secur have effectively made my decision for me -- if I do ultimately decide to become a card-carrying member of the 21st century and get a smartphone, an iPhone 6 it shall be.

                                   MP3 Player       Consumer Electronics are susceptible to damage caused by ESD, which can be generated from sources such as human contact or air discharge. Protection from these threats lies in the individual discrete protection for I/O ports at all equipment levels. Protection can also be provided at the system interconnecting ports. The protection schemes outlined are recommended for low insertion loss, high signal integrity and low noise/crosstalk with increasing bandwidth. CitrusCom's products provide protection from the effects of ESD/EFT/Surges as defined by IEC 61000-4-2, IEC 61000-4-4 and IEC 61000-4-5.

For special projects, I keep an inexpensive MP3 player handy as I'd rather not tie up or risk my smartphone. Recently, when I pushed the "off" switch, the player wouldn't turn off: in other words, it wouldn't shut up because it wouldn't shut down. It was small-scale version of those scary movies where the killer robot or machine is unstoppable, until someone, somehow, figures out how to get to the unit and shut off the power. I assumed the switch wasn't making proper contract. No big deal, I cracked open the case to see what I could do (one of the virtues of it being a cheap, "don't care about it" player), found the switch on its PC board, and jumpered across the terminals. It still wouldn't quit. Aha ... the problem was apparently not with the switch itself, but some software/hardware soft-failure glitch whereby the unit didn't recognise or respond to the switch closure. I thought to disconnect the battery, but it was soldered in, so that avenue of easy termination was closed off. So I just let the unit run down its battery all the way, then recharged it, which forced a software reset (as I expected it would). I have always been uncomfortable with presumed "on/off" switches and buttons that really aren't, but which actually are soft functions. This is where the system processor must recognise a switch closure, and put the unit into a quiescent sleep mode (and do the opposite to wake up). That is not the same as cutting off the power source. It assumes that everything is working just right, and the switch closure will be sensed and acted upon. I know that these soft functions including power controls are now standard on many products, but they still making me feel a little creepy. Obviously, a stuck MP3 player which won't turn off is not a crisis. But a motor, vehicle, or instrument that won't turn off: well, that's another story. Sometimes you can get to the power source and kill it, by pulling the plug or battery connector, but sometimes you can't. Or perhaps you could, but it would be too late. Many years ago, I worked for a company that made industrial machinery, powered by big electric motors or hydraulic pumps. For many years, everything was controlled by true hardware, such as switches and relays. As software and processor-based controls came into their own, we switched the controllers over, of course. But a big, red, unambiguous, mushroom-topped STOP switch which interrupted primary power was still key part of every system, for obvious reasons. Have you ever had a system which you couldn't get to turn off or stop-but needed to? How did this experience affect your design approach? Bill Schweber EE Times