My guess is that the instability some people see is tied to the power supply. If you use the Elk or a battery stabilized supply my guess is your problems go away. This is why it was important for me to put my XEP on the elk supply and to ensure I have a decent amount of battery capacity.
All computers benefit from being on UPS power.
Microcontrollers do not like unstable power supplies. Ripples are bad news.
Here is why I think they are bad news:
CPU's store information as either a high or low. As systems have strived to consume less power, they have lowered the operating voltage. In old electronics you used +12v and -12v as your high and low. Modern computers used +12v and 0v. Newer computers have continued dropping.... it's down to 1.5v and 0v. If your power supply fluctuates for a part of a cycle you might be seeing voltage drop down a bit. A computer might count anything above .8 as a 1 and anything below it as a 0. I believe in practice it's actually the opposite, but I'm not engaged in hardware engineering this month.... so don't get me to lying!
The digi embedded port has a CPU in it as well. It's tiny stuff to fit in a small package and tiny stuff generally uses +5v at best. More than likely it's a 3v or lower chipset. Very small fluctuations in the power supply will cause it to appear to "freeze" or lockup. With the stock power supply you are guaranteed to get those when your utility has their normal daily fluctuations.
What can cause a fluctuation in the incoming voltage? Practically anything... here are some examples:
- Your laser printer fires up and causes voltage drop.
- The business down the street fires up their evil scientist voltron lab pulling 1500Amps at 480v and causing a 2v drop for everyone served by their substation.
- A power plant shuts down and hands off it's load to another one.
- Your wife turns on the oven and all 4 electric burners at the same time taxing your already outdated electrical service.
At my last house we had an industrial neighbor a block away. Everyday at 8am they did something that caused all the UPS units in my house to alarm.
I keep all my computers, network gear, and Tivo on a UPS unit. The majority of power outages are just a few minutes long, so you don't need much. In my case I tend to use 1200va or 1500va TrippLite units. I also like APC but they want too much for the fancy displays that tripplite offers.
It's also worth noting, bit of a tangent... get a higher rated power supply for your computer. They have bronze, gold, silver, and platinum efficiency ratings. Your computer rarely runs at full tilt, so you almost never get rated efficiency. An unrated power supply is about 56% efficient when running less than peak. A higher rated power supply is more efficient at a non-peak load. This usually will pay for itself with today's power saving computers.
