SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE
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JUdGEMENT OF OIl lEVEl
When sufficient oil is in the crankcase, both of inner and
outer electrodes are immersed in the oil through which
current flows across the electrodes. The sensor judges
that oil in the crankcase is sufficient. When oil level
goes down and the inner electrode is exposed to the
air due to consumption of oil, no current flow between
the electrodes as air is considered to be electrically
nonconductive. The sensor in this case judges that oil
is insufficient.
dECISION OF OIl SHORTAGE
Oil level at the electrodes may go down momentarily
probably due to the engine being slanted or affected by
vibration even if a sufficient oil is in the crankcase. For
that reason, the sensor has an electronic timer circuit to
prevent it from interpreting as short of oil when amount
of oil is sufficient. The sensor has been designed so
that the engine is to be stopped only when oil-shortage
is detected for 5 seconds uninterrupted. The timer
employs an integration circuit and it is to be reset when
the inner electrode is soaked in the oil again before the
sensor decides it as oil-shortage. The oil level where
the sensor decides as oil-shortage, when oil level goes
down gradually, is cold “threshold level”
AUTOMATIC STOP OF ENGINE
When the sensor decides as oil -shortage, it makes the
engine to stop running automatically for protection of
engine. Once the stopping circuit is activated, it keeps
functioning until it confirms that the engine has made
a complete stop, then the circuit stops functioning
automatically.
POWER CIRCUIT
This rectifies a part of the igniter and regulates it to supply
the stabilized power to necessary circuits.
dETECTION CIRCUIT
This detects quantity of oil, sufficient or not, according to
difference of electric resistance across inner and outer
electrodes
dElAY CIRCUIT
This delay prevents the sensor from making an
unnecessary stop of the engine by momentary lowering
of the oil level due to the engine being slanted or affected
by vibration in spite of sufficient oil in the crankcase.
BlOCK dIAGRAM OF THE CIRCUIT
CAUTIONS TO BE TAKEN ON
HANdlING THE SENSOR
OIl SENSOR UNIT
Be sure not to damage each wire. Broken or short-
circuited power supply wires and/or a grounding wire in
particular may lead to malfunction or breakdown.
The sensor is not interchangeable from the engine
because the sensor is to be exclusively installed
individually in each engine employed
MOUNTING ANd WIRING OF OIl SENSOR UNIT
Although this has been designed to have enough
antinoise properties in practical use, do not route the
sensor wirings in the vicinity of noise-generating sources
such as ignition plugs or high voltage cords. This may
cause malfunction or breakdown.
Since capacity of power source is limited, current flown
in the electronic circuit of the sensor is kept as low as
possible. Be sure to use terminals with a high contact
reliability of more than that of tinned terminals
OPERATION OF OIl SENSOR
If operating with the engine kept tilted, oil surface inside
of the engine varies and the correct oil level can not to be
detected which in turn obstructs the preventing function
of engine seizure. Operate the engine by keeping it
level.
When starting the engine with an insufficient oil in the
crankcase, engine starts once then it stops automatically
after it runs for 5 seconds.
When the enginne has been stopped by the oil sensor,
voltage remained in the electronic circuit prevents the
sensor from being restarted for 3 seconds after the
engine stop. Try to restart the engine after 3 seconds
or more.
STOPPING CIRCUIT
This automatically stops the engine running.
