FR2515588A1 - Vehicle speed dependent timer for windscreen wiper control - receives signal from contact breaker to trigger timer in wiper motor drive control circuit - Google Patents

Abstract

A signal from the vehicle contact breaker passes through a low pass filter to a frequency to voltage converter. The output voltage is adjusted by a potentiometer and is attenuated by a potentiometer prior to entry to a trigger circuit to which upper and lower reference voltage signals are applied. The trigger circuit output signals are amplified by transistors to control a timer. One transistor stage enables the windscreen wipers to operate at normal speed when the vehicle is travelling at a partic. speed. The timer drives transistor stages to operate a relay to power the wiper motor. A capacitor and diode permit the short pulse from the timer to be lengthened to ensure the wiper motor operates.

Description

b) The present invention will put the windshield wipers into operation
time delay whose time is automatically adjustable according to the
vehicle size.

c) This device is especially useful in town. The driver will not have
5 touch the wiper switch each time the vehicle stops
which often happens in traffic jams. Also when
the vehicle is picking up speed, the rain water is getting more
quickly on the windshield, hence the usefulness of having short times
accelerating.

d) 10 The wiper timer has automatic adjustment according to the
speed allows time between sweeping, long idling
and runs when the vehicle accelerates. When the vehicle is at
idle the time between scanning is approximately 10 s. Other times
are: 8 s, 6 s, 4 s, and normal running at a certain speed.

e) 15 The attached drawing is a 1/1 assembly diagram.

f) The circuit is made up of 5 distinct parts
1 - the low pass filter
2 - the frequency-voltage converter
3 - the analog trigger
20 4 - the adjustable timer
5 - the power interface between the circuit and the motor
wipers.

The breaker output signal (for petrol vehicles) and
of the alternator (for diesel vehicles) is first
25 decoupled by the low pass filter (R1, R2, Z3, C4) which is applied
at the input of circuit A, terminal 1, frequency-voltage converter.

The compared reference voltage is fixed by the network
(R9, R10, D8).

The output voltage is adjustable by the potentiometer (P6) and
30 the capacitor (C7) at terminals 3 and 4 of circuit A. The voltage
output (limited by Roll) of circuit A at terminals 5/10 east
This will give the impulse to the wiper motor. The
diode 63 cancels the self-induction due to the breaking of relay R.

Capacitor C62 is paralleled to the supply of the
circuit, this to absorb parasites coming from the vehicle's electrical accessories.

applied and attenuated by the potentiometer (P13) which is mounted as a voltage divider. It is then limited by resistance
(14) and damped by the capacitor (12) to finally supply the input 17 of the analog trip device B. The diode (15) catches the input signal when it exceeds 5.4 V and protects the integrated circuit B against input signals too high.

Circuit B requests reference voltages, one upper terminal 3 and the other lower terminal 16. The upper voltage is obtained by the resistor (16) and the Zener diode (17), the lower voltage is grounded. Terminals 1 and 18 of the circuit
B must be applied at a voltage between 10 to 18
Volts (for 12 V mounting). Terminal B (2) adjusts the voltage available at output terminals B4 to B15 and thus controls the intensity to trigger the different sweep times. At the outputs of the analog trip unit, the signals are amplified by the transistors (T38, T39, T40, T41) controlled by the resistor network, diodes and light-emitting diodes (led 19, R24, D21, R25, D22, R26, D23). These amplified signals are connected to terminals 6 and 7 of the integrated timer circuit C. The last output signal amplified by the transistor (60) controlled by (R61, led 28) allows, at a certain speed of the motor vehicle, to put the essies -window in normal operation. The adjustable timer circuit consists of an integrated circuit, passive and active components.

 The RC network (R46 and C47) determines the trigger time base of circuit C. Terminals 4 and 8 of circuit C are connected to the positive blade and terminal 1C to ground. Circuit C is triggered by a negative pulse at terminal 2C, via R48. This pulse is given by a closing contact of relay R. Pin 5C is decoupled using capacitor C49. The 3C output is amplified by the transistorts 52,56 controlled by the resistors 50, 51 and 55.

The pulse at the output 3C is very short and to overcome this drawback, we add a capacitor C54 and a diode 53 at the base of the transistor T56 via the resistor 55, which makes it possible to extend the bonding time of the relay R and start the wiper motor. The transistor T56 controls the relay R.

Claims (6)

1) Self-adjusting wiper timer  depending on the speed of the vehicle, characterized in that it  has an electronic circuit composed of a pass filter  bottom (1), a frequency / voltage converter (2), a  analog trigger (3), with an adjustable timer (4),  a power interface between the circuit and the motor  wiper (5). 2) Self-adjusting timer for wiper  according to claim 1, characterized by a pass filter  bottom consisting of resistors 11 and 12, a Zener diode 3,  and a capacitor 4. This network is connected either to the signal  output of the contact breaker (in the case of a petrol car), or  to the alternator output signal (case of a car at  diesel fuel). 3) Self-adjusting timer for wipers  according to claim 1, characterized by a converter  frequency / voltage composed of integrated circuit A, of the potentio  meter 6, capacitor 7, diode 8, and resistors  these 10 and 11. This circuit transforms the frequency coming from  low-pass filter in a linear voltage. 4) Self-adjusting timer for wiper  according to claim 1, characterized by a trigger  analog composed of an integrated circuit B, a potentio  meter 13, a capacitor 12, diodes 15, 21, 22, 23,  of Zener diode 17, resistors 35, 32, 31, 18, 20, 24,  25, 26, 27, 30, and light emitting diodes 19, 28.  time between scanning.  applied to the timer circuit <4) for the different  35, 36, 37, 61 via transistors 8, 39, 40, 41, 61, and  whose latter are amplified by resistors 34,  Linear voltage is transformed into several voltages  5) Self-adjusting wiper timer  according to claim 1, characterized by a time delay  adjustable sensor made up of an integrated circuit C, resis  tances 42, 43, 44, 45, 46, 48, 50, 51, capacitors  47, 49, 51, and transistor 52. The circuit gives im  pulses every 10s at idle and every 8s, 6s,  4s in acceleration. 6) Self-adjusting wiper timer  according to claim 1, characterized by an interface for  power between the control circuit and the motor. he  is made up of resistor 55, transistor 56,  diode 63 and relay 57. This interface is working  instantaneous with each impulse given by the circuit  timer; as a result, the wiper motor moves.