Pangolin FB4 Series, User Manual

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18 FB4 User Manual
We will discuss the connections for the scanner power supplies first,
because they are at the top of the diagram, and also because once that
foundation is laid, the other power connections can be easily
understood.
Power enters the projector from the AC Mains Supply. An integrated
switch and fuse assembly is often used as shown. The international
color standard specifies the brown wire as the LINE (or “Hot”) lead,
and the blue wire as the NEUTRAL lead. These are connected to the
power supply LINE and NEUTRAL connections respectively. If you
look closely at the power supply, you should see the words “Line” and
“Neutral”, or letters “L” and “N” that designate which wire goes
where.
Note that there are AC power cords that do not have polarized plugs,
and these two may become swapped at the point that the projector
plugs into the wall. However, you should still maintain a sense of
“Line” and “Neutral” throughout the laser projector, always
connecting the “Line” terminals of all power supplies to the same
(preferably brown) wire, and “Neutral” terminals to the other
(preferably blue) wire. The most important difference between the
“Line” and “Neutral” connections, is that the “Line” connection is the
one that you use when connecting a switch and fuse in line with
power supplies.
With laser projectors whose optical output power is relatively low (for
example, a few hundred milliwatts) and projectors that have a plastic
enclosure, there may only be two AC power wires (Line and Neutral)
and the Ground wire may or may not be used. For projectors that have
a metal enclosure, a Ground wire (international color code is green as
shown) must always be used and connected as shown.
The Power Connections diagram shows two separate power supplies
used to ge24V and –24V for the scanner amplifiers, but this
could be embodied as a single power supply that generates both
voltages as indicated by the light gray box. In either case, the +24V
and –24V power wires are connected from these power supplies to the
scanner amplifiers. As with the power supplies, the scanner amplifiers
may also be embodied as two separate single-axis amplifiers, or as
one dual-axis amplifier as indicated by the light gray box around
them.
The most important part of Figure 1 is the “Central Grounding Point”.
This is really the single most important connections concept inside the
laser projector, and the thing that many people do not initially