Over the years, folks who have asked my opinion of bulbs have
learned that I don’t favor them. Here’s why. They can isolate
one section of the layout from another. For example, they can
prevent a short in one yard from impacting operations in an-
other yard. However, the full bulb current is flowing in the path
from the bus through the bulb and the short. If one uses a ro-
bust bulb, for example one that as a 2.1-amp rating, then the
short (perhaps a wheel crosswise on a turnout) is carrying the
full current. Yes, the power is being limited by the bulb, but
current can pit and even spot-weld parts. Also, the DCC system
is supplying that power, about 30 watts (15 volts X 2.1 amps)
to the short.
Even with their limitations, bulbs still are being installed on lay-
outs. Let’s look at their pros and cons.
2. CP6 - 6-bulb circuit protector from NCE. NCE Corp. photo.
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