Page 123 - Build Your Own Quadcopter_ Power Up Your Designs with the Parallax Elev-8

102 Bu il d Y o ur O w n Q u a d c o p t e r

Most ESCs, especially those made in China, are covered in a large heat shrink tube that
prevents inadvertent short circuits and offers some physical protection to the PCB
components. This type of covering, while very inexpensive, does not readily dissipate
internal heat or allow easy access to onboard components. I did remove the heat shrink tube
from a 25-A Turnigy ESC to show you the components that are hidden beneath it. The front
side of this ESC is shown on the left side of Figure 5.11, while another exposed ESC photo
that I gathered from an R/C website is shown on the right side of the figure.
A comparison of the two boards should reveal that despite being from different sources
they are almost identical, at least as far as component type and placement. I believe that
Chinese manufactured ESCs are produced at only a few factories and then sold under a
variety of brand names. It is very much a commodity market, and you are quite likely to
receive exactly the same ESC for a particular amperage rating, no matter the branding. There
is another, darker side to this type of marketing that you should also know about. Some
unscrupulous marketing companies buy rejected ESCs from reputable distributors, rebrand
them, and then sell them as fully functional ESCs. I would strongly suggest that you purchase
only from reputable dealers and distributors and avoid the secondary market, where you
may get a much cheaper price, but also much lower quality. Remember that the ESCs supply
the power to the motors that keep your expensive quadcopter aloft.

Figure 5.11 Two exposed ESC boards.