IK642BN Datasheet, PDF (4/11 Pages) IK Semicon Co., Ltd – INTERVAL- and WIPE/WASH WIPER CONTROL IC

IK642B
CIRCUIT DESCRIPTION
Interval Function, Pin 2
By closing the interval switch, S₂, to supply voltage, V_Batt, the relay is activated. The internal
current source (pin 3) which holds the capacitor C₂ in a charged state is switched-off. As soon as
there is a positive potential at the park switch (S1), the current source F (see Figure 1 on page 1)
charges the capacitor C2 very quickly. After the wiper operation is finished, S₁ is again at ground
potential, the relay is in the off position - interval pause begins -the capacitor C₂ is discharged
through the current source C, till the voltage at pin 3 is below the threshold of 2 V. Interval pause
can be adjusted between 4 s to 20 s with the help of potentiometer R₃. Now the relay switches on
and the next interval cycle begins. Opening of switch S₂ causes the current source A to discharge
C₂ immediately and current sources C and F are switched-off.
Wipe/Wash (WIWA)
Operation, Pin 5
By closing the WIWA switch, S₃, to supply voltage, V_Batt, the water pump starts spraying water
on the windshield. During this function, the current source A is switched-off which keeps the
capacitor C₂ in a discharged state. Now the capacitor is charged through the current sources D and
F. If (after a time interval of approximately 100 ms) the voltage at the capacitor is greater than 6.5 V,
the relay is turned on as long as the switch WIWA is closed.
The after-wiping time begins when the switch is open, the sources D and F are switched off
and the source E is activated. Source E discharges the capacitor until the voltage is less than 2.2 V.
The relay is off and the wiper-motor is supplied via the park switch until the park position is reached.
The after-wiping time is determined by the current source E which can be regulated with the
external resistor R_Time. When the after-wiping time has elapsed, the source A discharges the
capacitor. The relay switch is independent of the park switch S₁.
Interval and WIWA
Functions
The interval function is interrupted immediately when the wipe/wash mode is activated. The
current source A discharges the capacitor to a value of 2 V, afterwards, the normal wash function
starts.
Interval wiping starts immediately when the after-wipe time is over. The switching delays are
slightly shorter, because the capacitor is already charged to a value of 2 V.
The wipe/wash function is not interrupted when the interval switch S₂ is activated.
The interval function begins after the WIWA function has elapsed.
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2013 June, Ver. 00