Sinking & Sourcing II Video Lecture | Digital Electronics - Electrical Engineering (EE)

here we have our 24 volt DC source a
fuse our DC input module and our field
input device we're asked to connect the
circuit and we can use conventional flow
theory to show it or an electron flow
theory we're going to choose
conventional flow theory and so we start
at the positive side and come through to
the fuse and from the fuse this time
we're going to come down all the way to
the common and it again it will go
through the internal circuitry come over
the input to the DC field device and up
through and after a negative to course
is attached to Brown so if you look at
this circuit comes through here once
this DC field device closes then it'll
turn on the internal circuitry and
everything will be fun
now if we're asked to figure out which
is sourcing and sinking in this one well
again we follow the direction of current
flow just coming down here and from the
source so in this case this DC module
will be sourcing and the DC field input
device will be sinking
now that was opposite to the circuit we
had before now over here this wiring
would be out in the field and if it
developed a ground on that wiring let's
look and see let's analyze this and see
what would happen we could come out of
here come across through the fuse
through the internal circuitry and to
grow
now this internal circuitry would always
be high and we would lose our control
over here it wouldn't matter if this was
on or off this circuitry would be high
so this could be on or off and it would
not matter now this could end up being a
dangerous situation because we're losing
control and if we lost control if this
was operating this switch was operating
turning on a saw blade or a solenoid or
something like that that was doing some
type of action it could end up injuring
a person and or damaging equipment so
this type of circuit even though the
work in the event had developed the
ground on the DC field input wiring it
could be a hazardous situation