IEEE Power & Energy Magazine - January/February 2018 - 62

even further. this closure reduces
the arc voltage and hence reduces
the influence of S2. S1 is allowed
to assert control and move the elecK
P
trode back up to the control range
N
at G. the process repeats until the
usable portion of the upper electrode
has been consumed.
this process has simplified
C
the
control process and does not
r′
properly
portray the sophistication
S
S
required
by a well-designed arc
r
v
u
lamp regulator. For instance, in
z
Figure 5, there is no resistor shown
z
R
in series with the coils. this was
often provided to determine the
c
j
i
set point or the voltage at which the
arc is to be controlled. this could
be somewhat different for each
u
v
lamp in a series string. this string
would often contain more than 100
lamps. another resistor might be required to reduce the tendency of the
figure 7. A detail of the operating mechanism.
coils'
inductance to cause the elec(From Electric Lighting and Railways. Scranton,
trodes
to oscillate or "hunt" during
PA: ICS, 1901.)
the changing of the arc length. the
removal of a lamp from the string
due to malfunction or maintenance
would cause a momentary change in
current through the lamps. this might
also result in electrode oscillation. today, this control system might be mathematically analyzed for stability. Whether
or not that was done in the design of
any turn of the century arc lamp would
be interesting to determine.
Figure 7 shows details of the operEarly
Registration
ating mechanism, with the outer proDeadline EXTENDED!
tective can removed, of a brush elecRegister by
tric Company series dc arc lamp. the
globes, which are not shown in this
- to -
6th Annual
figure, would be mounted below. the
series coil is labeled S (S1 in Figure 5),
and Sl is the shunt coil (S2 in Figure 5).
the control stabilizing resistances are
shown as r and rl. N and P are the
25-28 March 2018 | Frankfurt, Germany
negative and positive terminals of the
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lamp, which take the form of hooks
professionals from Europe and
around the world
used to attach the lamp to a supporting
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bracket arm. K is the switch used to
compliance & ethics challenges, including
anti-corruption, data protection, and
"short out" the lamp when it is to be rerisk management
moved or worked on. this lamp has two
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and take the Certified Compliance & Ethics
z. R is a rocker arm that attaches to the
Professional - International (CCEP-I)® exam
armature (not visible in this figure) that

the lamps are installed. a means
of feeding the upper electrode into
the control range is required.
Initially, this was accomplished
by a clockwork mechanism. by the
beginning of the 1880s, most arc
lamp feeding mechanisms took the
form of a clutch. In Figure 6, this
clutch is represented by a disk with
an internal diameter just slightly
larger than the outer diameter of
the top electrode. under its own
weight, the upper electrode will
slip through the disk when it is horizontal. but if the disk is not held
horizontal, it will tend to be rubbed by the close-fitting electrode as
the electrode moves by. this will
cause the disk to tip and grab the
electrode, stopping the electrode's
downward motion.
at e, the disk is forced horizontal because it has hit a stop. the disk
no longer holds the electrode, which
slips down F, closing the arc gap

European

22 JAN
SAVE

Compliance & Ethics Institute

EuropeanComplianceEthicsInstitute.org | lizza.catalano@corporatecompliance.org

http://www.EuropeanComplianceEthicsInstitute.org

Table of Contents for the Digital Edition of IEEE Power & Energy Magazine - January/February 2018