U642B
Pin Configuration
Pin
1
2
3
4
5
6
7
8
Symbol
GND
Input 1
t
c
R
4
WIWA
S
1
RELAY
+V
Batt
Function
Ground
Interval switch
Timing capacitor C
2
Afterwiping time resistance
Wipe/Wash switch
Park switch for wiper motor
Relay control output
Supply voltage KI. 15
GND
Input 1
t
c
R
4
1
2
8
7
+V
Batt
RELAY
S
1
WIWA
U642B
3
4
93 7691
6
5
Figure 2. Pinning
Circuit Description
Interval Function, Pin 2
By closing the internal switch, S
2
, to supply voltage,
+V
Batt
, the motor is activated. The internal current source
(Pin 3) which holds the capacitor C
2
in charged state is
switched-OFF. As soon as there is a positive potential at
the park switch (S
1
), current source F (see figure 1)
charges the capacitor C
2
very fast. After the wiper
operation is finished, S
1
is again at ground potential, the
relay is in OFF position – interval pause begins – the
capacitor C
2
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 R
3
. Now the relay switches ON and
the next interval cycle begins. Opening switch S
2
causes
current source A to discharge C
2
immediately and current
sources C and F are switched-OFF.
at the capacitor is greater than 6.5 V, the relay is turned
on as long as the switch ”WIWA” is closed.
The after-wipe-time begins after the switch is open
whereas the sources D and F are switched OFF and the
source E is activated. Source E discharges the capacitor
till the voltage is less than 2.2 V. The relay is OFF and the
wiper-motor is switched OFF. The after-wipe-time is
determined by the current source E which can be
regulated with the external resistor R
Time
. Afterwards the
source A discharges the capacitor. Relay switch OFF is
independent of the park switch S
1
.
Interval and WIWA Functions
The interval function is interrupted immediately when the
switch S
2
is activated. The current source A discharges
the capacitor to a value of 2 V, afterwards the normal S
2
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 interval
switch S
2
is activated. Interval function begins after the
WIWA function is over.
Wipe/Wash (WIWA) Operation, Pin 5
By closing the WIWA-switch, S
3
, to supply voltage,
+V
Batt
, water pump starts spraying the water on the wind-
screen, the current source A is switched-OFF which keeps
the capacitor C
2
in discharged state. Now the capacitor is
charged through the current sources D and F, and when af-
ter a time interval of approximately 100 ms, the voltage
2 (6)
TELEFUNKEN Semiconductors
Rev. A1, 13-Feb-97
TEMIC [ TEMIC SEMICONDUCTORS ]
