Power Supply Ideas and Precautions.

The D100 requires a WELL REGULATED 5 volt power supply. It is easier to damage the D100 when applying voltage to the 5 volt line than to the motor B+ line.

That's why... PLEASE PLEASE PLEASE... Go through all of this Information Before Attempting to Run the Board. 

First: Meet the LM7805

Warning!
Whether you already own a 5 Volt power supply or follow this instructions to build one, please MAKE  SURE that you have the proper voltage and polarity BEFORE applying it to the board.

A safety precaution
First of all: If building your own power supply, make sure you use an LM7805 and not an LM7805L. Also: Don't forget to use a heat sink for the LM7805. 

5 Volt Power Supply Schematics.

The difference between the two following schematics is that Fig 1 uses 1 diode for rectifying the AC voltage and Fig 2 uses 4 diodes as a bridge rectifier. In most cases - just to power the board - the design from Fig 1 is enough.

The 7-16 Volts AC voltage can be supplied by a 150mA or higher power transformer.
Fig. 1

Even though not shown in Fig 1 and Fig 2, in a noisy environment, a .1uf monolithic or ceramic capacitor can be connected in parallel with C2 to improve filtering.
  Fig. 2

Note: In Fig. 1 and Fig. 2 it's assumed that an AC voltage transformer (also known as converters, i.e.: 120VAC to 12VAC) will be used thus requiring the rectifying input diodes.

If using a DC transformer or powering your project from batteries disregard using the input diodes and C1, C2 can be as low as: 47uf.
Also, remember that the minimum input voltage at the LM7805's input must be at least 7.0 DC volts and no more that 26.0 DC Volts.  

Protecting the board from Higher that 5.5 volts and Wrong Polarity
Please Don't take any chances and follow this suggestion.

Higher that 5.5 volts can be applied in different ways:

By accident:
Many users use variable power supplies, they may be applying 12.0 volts to a different project, then they forget to adjust the power supply down to 5.0 volts before they apply it to the D100's 5 volt line.
A power supply gone bad:
Most often, when power supplies or voltage regulators go bad, they deliver a lot more than the regulated voltage that they are suppossed to.

Components on the D100 board will be destroyed if the power supply gets higher than 5.5 volts.
So to protect it, it's strongly recommended to install a 5.6 1W zener diode across the board's input supply in the D100's component location: Z1

Protecting Both the Board and The Power Supply.

When using a very strong transformer, 1A or more, installing a current limiting resistor at the 5V input provides some protection for a few seconds untill you notice that the board doesn't work and then notice that you applied the 5 volt line with the wrong polarity.

You might have to experiment with different values for R1, depending on your power supply transformer. If preferred a 250mA fuse can be used, but the limiting resistor will save you a fuse every time you apply the wrong polarity voltage to the board, providing you protected your board against wrong polarity input as by installing a zener diode at location: Z1 on the board.