JP2548778Y2 - Wiper control circuit - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control circuit for a wiper provided in a vehicle or the like, and more particularly to a device for performing continuous and intermittent operations.

[0002]

2. Description of the Related Art FIG. 3 shows a circuit for continuously driving a rear wiper provided at the rear of an automobile. This operation will be described. When the external switch 4 is turned on to operate the rear wiper when the accessory switch 2 is in the on state, the drive motor 62 continuously operates the rear wiper. When the external switch 4 is turned off, power is supplied and stopped at a predetermined position until the sliding contact switch 72 that operates synchronously with the wiper is turned off.

Further, there is a demand that the rear wiper be operated intermittently in accordance with the environmental condition. For this reason, a switch for selecting continuous or intermittent operation is newly provided and operated by a timer. I was

[0004]

However, in order to perform the above-mentioned intermittent operation, a newly provided selection switch and control circuit must be provided in the vicinity of the instrument panel of the automobile. It is becoming difficult to secure this space.

[0005]

According to the present invention, the input signal of the external switch for instructing the operation of the wiper is turned off.
Stop after a predetermined time of cropping, and
A control circuit for switching the operation cycle of the wiper by a time- off operation is provided.

[0006]

According to the structure of the present invention, when the external switch is turned on, the operation signal is output from the operation signal output circuit, the operation signal is continuously operated for a predetermined time, and then the operation signal is stopped. , An intermittent operation is performed. Thereafter, when the external switch is turned off for a short time, an operation signal is output from the operation signal output circuit to stop the timer circuit and perform continuous operation. After that, the timer circuit and the operation signal output circuit are switched by the short-time OFF operation to output the operation signal. Therefore, it is possible to switch between the intermittent operation and the continuous operation without newly providing a selection switch.

[0007]

FIG. 1 is a circuit diagram of a control circuit for a rear wiper according to the present invention. Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The control circuit of the rear wiper according to the present invention includes a power supply circuit 10, an operation signal output circuit 30, a timer circuit 80, and a motor drive circuit 90. The power supply circuit 10 includes diodes 12 and 22, resistors 14 and 18, a noise prevention capacitor 16, a constant voltage zener diode 20 and a delay capacitor 26.
And outputs the operation signal in response to the external switch 4 and supplies the power supply voltage VDD to the control circuit. This power is supplied for a predetermined time even if the external switch is turned off by the capacitor 26.

The operation signal output circuit 30 includes a capacitor 3
2, 40 and D flip-flop (hereinafter referred to as FF) 3
6, 38, resistors 46, 48, 52, 56, 58, diodes 42, 44, a transistor 50, and an inverter 54. When the power supply voltage VDD is supplied, an H level operation signal is output for a predetermined time, and an external signal is output. When the switch 4 is turned off for a short time, an H-level operation signal is output until the external switch 4 is turned off. The timer circuit 80 includes an oscillator 82 and a frequency divider 84.
, A counter 86, and an AND gate 88, which start oscillating by the supply of the power supply voltage VDD, output an operation signal at predetermined time intervals, and output an operation signal from the operation signal output circuit. The operation is stopped.

The motor drive circuit 90 comprises an OR gate 92, diodes 94 and 96, a resistor 102, a relay 100, and a transistor 104. The motor drive circuit 90 receives the operation signal from the operation signal output circuit, the timer circuit, and the operation signal from the sliding contact 72. A drive signal is output to the motor 62 in response.

Next, the operation of the control circuit of the rear wiper having the above configuration will be described with reference to the time chart of FIG. When the accessory switch 2 is turned on at the time of starting the vehicle, the output signal B0 becomes H level. When the external switch 4 is turned on to operate the rear wiper, the capacitor 26 is charged via the diode 22. Later, the power supply voltage VDD is supplied. At this time,
The operation signal of the external switch is output via the diode 24, but the FF 38 does not operate because the power is not yet supplied during the charging time since the FF 38 is in the rising operation. When VDD is supplied, the FF 36 is at the H level for both the set and reset terminals.
The output goes high to output the signal S2. As a result, the FF 38 is set.
3 is at the L level. Accordingly, the transistor 50 is turned on, and the H-level operation signal S4 is output via the inverter 54.

On the other hand, the supply of VDD causes the timer circuit 8
0 oscillator 82 starts oscillating.
Since the frequency divider 84 and the counter 86 are reset by the signal, the output is stopped. Further, the S4 signal is input to the drive circuit 90 to turn on the transistor 104 via the OR gate 92 and output a motor drive signal via the relay 100, so that the rear wiper operates continuously. When the capacitor 32 is charged after a predetermined time, FF
36, the set terminal is at H level and the reset terminal is at L level.
0 is turned off, the drive signal S4 is also at L level, and the reset of the timer circuit 80 is released, and the timer circuit 80 is set to H at predetermined time intervals.
A level operation signal S5 is output. Therefore, the operation becomes an intermittent operation.

Next, if the external switch 4 is turned off for a short time during the above operation, that is, turned on again while the operation of the logic circuit is maintained even if the capacitor 26 is discharged, this signal is output to the diode. Since the inverted Q output is input to the L level through the clock terminal 24 and the L level is also input to the data terminal, the FF 38 performs the inverting operation and sets the signal S3 to the H level. Therefore, the continuous operation is performed as described above. In this state, if the external switch 4 is again turned off for a short time, the FF 38 is inverted and the inverted Q output becomes L level, so that the signal S3 becomes L level and the operation signal S4
Stops and intermittent operation is performed. Therefore, switching between intermittent and continuous is performed by a short off operation. In the initial stage of the intermittent operation, the capacitor 32 operates continuously for the charging time. This makes it possible to respond even when using a washer.

In the embodiment of the present invention, the operation cycle of the intermittent operation is one stage. It can be operated periodically. Further, the present invention can be applied not only to the rear wiper but also to a wiper provided on the front surface.

[0014]

As described above, since the wiper control circuit of the present invention cuts off the power supply a predetermined time after the external switch 4 is turned off, the power supply is cut off within a predetermined time until the power is cut off. The intermittent operation and the continuous operation can be switched by the time-off operation, and there is no need to provide a new switch. Furthermore, the intermittent operation can be added by connecting the terminals A, A, C, D, and O to the corresponding terminals of the conventional continuous operation circuit shown in FIG.
This control circuit does not need to be installed on the narrow instrument panel at the front part, but can be installed near the main body, and can be easily replaced according to the required functions such as multiple stages.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a rear wiper control circuit according to the present invention.

FIG. 2 is a timing chart showing the operation of the rear wiper control circuit according to the present invention.

FIG. 3 is a continuous operation rear wiper control circuit showing a conventional example.

[Explanation of symbols]

 Reference Signs List 10 power supply circuit 30 operation signal output circuit 80 timer circuit 90 motor drive circuit

Claims (1)

(57) [Scope of request for utility model registration] 1. A control circuit for a wiper provided in a vehicle.
From an external switch that instructs the operation of the wiper
Signal for a predetermined time after the external switch is turned off.
It shall be stopped later, and the off operation for a short time within the predetermined time
Control to switch the operation cycle of the wiper in response to the operation
The control circuit of the wiper, characterized in that a circuit.