Kubota u15-3, Руководство по ремонту

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WSM U15-3
II-134
i. Auto glow circuit
1. Function
1. The glow controller receives a water temperature sensor signal or a key switch start position signal and
makes the signal voltage (1) drop to the ground level. Now the current starts flowing to the relay coil.
(NOR signal circuit)
2. Turn the key switch from the OFF to ON position, and the glow relay is kept on for the time "t" as shown
in Fig. 2 (Function chart) to light up the glow lamp.
3. While the key switch is set at the ST position, the glow relay is turned on again to light up the glow lamp.
4. As indicated in Fig. 3 (Timer curve), the pre-glow time (glow lamp-on time) "t" is compensated depending
on the water temperature.
5. Once the current flows to the relay coil, the battery voltage starts flowing to the glow plug.
Reference: NOR logic circuit
The NOR logic circuit is a composite circuit of OR gate and NOT gate.
Water temp sensor signal Key SW ST signal
H H H L
H L H L
L H H L
L L L H
Key SW
ON
OFF
ST
5A
Key on
ON
Key st
ON
OFF OFF ST
ST
Glow relay
Glow plug
Glow lamp
OR
Water tempt sensor
Auto glow controller
ޓ
Battery
50A
t
H: High level, 12V
Indicates that a signal voltage
is applied.
L: Low level, 0V
Indicates that no signal voltage
is applied or that the terminal
is grounded.
OR