Apparatus for Controlling a Plurality of Electrical Devices

1. Field of the Invention

The present invention relates to an apparatus for selectively controlling a plurality of electrical devices through an operation switch.

2. Description of the Prior Art

In conventional systems, in general, any electrical device which can be adjusted by an operator is controlled by an exclusive-use operation switch. For example, electrical devices of an automobile, which devices can be adjusted by a driver, are controlled by corresponding operation switches. However, where the number of such electrical devices is increased, it may be difficult to provide all the corresponding operation switches, because of a lack of space. Particularly, there is limited space in the automobile for providing a large number of operation switches, and recent developments in car electronics have greatly increased the above problem of providing sufficient operation switches for the control of the increased number of electrical devices to be adjusted by the driver.

It is, therefore, an object of the present invention to provide an apparatus for controlling a plurality of electrical devices, which apparatus would not need a large space for the installation thereof.

According to the present invention the above object is achieved by an apparatus for controlling a plurality of electrical devices comprising: an operation means for controlling the electrical devices; a switching means for selectively connecting the operation means with one of the electrical devices; means for instructing the connection of the switching means; and means for controlling the connection of the switching means to connect the operation means with another of the electrical devices for a predetermined period of time when the above instructions are given.

Since a plurality of electrical devices can be controlled by a single operation means, a large space will not be needed for the installation of the operation means. Furthermore, as the operation means is connected with the other of the electrical devices on a time sharing basis, the operation of a plurality of the electrical devices is simplified.

FIG. 1 is a block diagram of a first embodiment according to the present invention;

FIG. 2 is a detailed circuit wiring diagram of the embodiment of FIG. 1;

FIG. 3 is a wave-form diagram illustrating the operation of the circuitry of FIG. 2;

FIG. 4 is a block diagram of a second embodiment according to the present invention; and

FIG. 5 is a detailed circuit wiring diagram of the embodiment of FIG. 4.

FIG. 1 illustrates a first embodiment of the present invention. In FIG. 1, reference numeral 10 denotes an operation switch fitted in the interior of an automobile, 20 an electrically-controlled exterior rear view mirror mounted on a fender of the automobile (electrically-controlled fender mirror), and 30 an electrically-controlled interior rear view mirror mounted in the interior of the automobile (electrically-controlled interior mirror). The operation switch 10 for controlling an actuator of the electrically-controlled fender mirror 20 and an actuator of the electrically-controlled interior mirror 30 is connected to a transfer switch 40. This transfer switch 40 normally connects the operation switch 10 with the electrically-controlled fender mirror 20. When energized, the transfer switch 40 transfers an electrical contact element 42 to connect the operation switch 10 with the electrically-controlled interior mirror 30.

A control circuit 50 is connected to the transfer switch 40 and produces a signal having a predetermined pulse width when a momentary-contact type push button switch 60 with normal contacts is actuated. The signal from the control circuit 50 is applied to and energizes the transfer switch 40.

FIG. 2 illustrates a detailed circuit construction of the control circuit 50. The push button switch 60 is connected to a transistor 51 in the control circuit 50. The collector of the transistor 51 is connected to the clock terminal of a D type flip-flop 52 via a Schmitt trigger circuit 53 and an inverter. The Q output terminal and reset terminal of the flip-flop 52 are connected to a timer circuit 54. The timer circuit 54 has a transistor 55 switched by the Q output of the flip-flop 52, a charge-discharge capacitor C.sub.1, a charge resistor R.sub.1, a discharge resistor R.sub.2, a diode D.sub.1, and a Schmitt trigger circuit 56 whose output is connected to the reset terminal of the flip-flop 52. The Q output terminal of the flip-flop 52 is connected to transistors 57 and 58 via an inverter. The transistor 58 is connected in series between the ground and the positive terminal of a battery 70 of the automobile via an exciting coil 41 of the transfer switch 40. The battery 70 is connected to a power supply circuit 59 for supplying a regulated constant voltage V to each component in the control circuit 50.

Hereinafter, the operation of the first embodiment of FIGS. 1 and 2 will be explained with reference to the wave-form diagram of FIG. 3.

Normally, the transfer contact 42 of the transfer switch 40 is switched to connect the operation switch 10 with the actuator of the electrically-controlled fender mirror 20. Therefore, the electrically-controlled fender mirror 20 can be controlled by operating the operation switch 10.

When the push button switch 60 is depressed, the output a of the push button switch 60 is lowered, as shown in FIG. 3, causing the transistor 51 to turn ON. Thus, the input b of the clock terminal of the rising-edge triggered flip-flop 52 changes from a low level to a high level, as shown in FIG. 3, causing the flip-flop 52 to be set. While the flip-flop 52 is set the transistor 55 is conductive, therefore, the voltage c at a node N.sub.1, which is the junction of capacitor C.sub.1 and the resistor R.sub.1, gradually rises, as shown in FIG. 3. The voltage increasing speed depends upon a time constant R.sub.1 C.sub.1, which is determined by the capacitance of the capacitor C.sub.1 and the resistance of the resistor R.sub.1. When the voltage c at the node N.sub.1 exceeds an upper threshold voltage of the Schmitt trigger circuit 56, the output d thereof changes from a low level to a high level, as shown in FIG. 3, causing the flip-flop 52 to be reset. As a result, the Q output e of the flip-flop 52 is maintained at a high level for a time period T, which is determined by the time constant R.sub.1 C.sub.1 after the push button switch 60 is actuated, as shown in FIG. 3. When the flip-flop 52 is reset, the capacitor C.sub.1 is discharged via the diode D.sub.1 and the resistor R.sub.2. When the voltage c at the node N.sub.1 drops below a lower threshold voltage of the Schmitt trigger circuit 56, the output d inverts from a high level to a low level. The duration of the high level of the output d depends upon a time constant R.sub.2 C.sub.1, which is determined by the capacitance of the capacitor C.sub.1 and the resistance of the resistor R.sub.1.

During the set period T of the flip-flop 52, both of the transistors 57 and 58 are conductive. Thus, the exciting coil 41 of the transfer switch 40 is energized, causing the operation switch 10 to connect with the actuator of the electrically-controlled interior mirror 20 during this time period T. As a result, the electric-control interior mirror 20 can be controlled by operating the operation switch 10 for the time period T. When the time period T after the actuation of the push button switch 60 has elapsed, the flip-flop 52 is reset and the transfer contact 42 of the transfer switch 40 returns to connect the operation switch 10 with the actuator of the electrically-controlled fender mirror 30. That is, the operation of the operation switch 10 is automatically returned from the electrically-controlled interior mirror 30 to the electrically-controlled fender mirror 20 without actuating the push button switch 60. The time period T can be freely varied by changing the time constant R.sub.1 C.sub.1. In this embodiment, the time period T is determined as approximately 25 seconds.

The above-mentioned control operation is not limited to the electrically-controlled fender mirror and interior mirror. For example, an electrically-controlled fender mirror and a power seat can be controlled in the same manner, or alternatively, an electrically-controlled interior mirror and a power seat can be controlled. Furthermore, other electrical devices can be controlled instead of the above fender mirror and interior mirror.

FIG. 4 illustrates a second embodiment of the present invention.

In this second embodiment, the operation switch 10 can control four electrical devices.

In the second embodiment shown in FIG. 4, the operation switch 10, the electrically-controlled fender mirror 20, electrically-controlled interior mirror 30, and push button switch 60 are the same as those of the first embodiment. In this embodiment, two more electrical devices, such as an electrically-controlled exterior front underview mirror (electrically-controlled front under mirror) 80 attached to, for example, a front portion of a box-body automobile, and an electrically-controlled exterior rear underview mirrow (electrically-controlled rear under mirror) 90 attached to a rear portion of the box-body automobile are further provided. The operation switch 10 is connected to a switching circuit 100. This switching circuit 100 has four relay switches 101, 102, 103, and 104 for connecting the operation switch 10 with the electrically-controlled fender mirror 20, interior mirror 30, front under mirror 80, and rear under mirror 90, respectively. The relay switch 101 is normally closed and thus the operation switch 10 is normally connected with the electrically-controlled fender mirror 20 in the same way as in the first embodiment.

In response to the actuation of the push button 60, a control circuit 110 produces a signal having a predetermined pulse width. This signal is applied to one of the relay switches 101, 102, 103, and 104, to close the applied relay switch. Namely, the relay switch to which the signal is applied is selected in accordance with the number of times that the push button switch 60 is actuated.

FIG. 5 illustrates a detailed circuit construction of the control circuit 110. The push button switch 60 is connected to a transistor 111 in the control circuit 110. The collector of the transistor 111 is connected to the clock terminal of a decade counter 112 and to the clock terminal of a D type flip-flop 113, via a Schmitt trigger circuit 114 and an inverter. The decade counter 112 produces a high level signal only at the Q.sub.0 output terminal before receiving a clock signal. If one signal is applied to the clock terminal of the decade counter 112, a high level signal appears only at the Q.sub.1 output terminal. If two signals are applied, a high level signal appears only at the Q.sub.2 output terminal, and if three signals are applied, only at the Q.sub.3 output terminal. Namely, depending upon the number of times the push button switch 60 is actuated, the decade counter 112 produces a high level signal at one of its output terminals. These Q.sub.0, Q.sub.1, Q.sub.2, and Q.sub.3 output terminals of the decade counter 112 are connected to the relay switches 101, 102, 103, and 104, respectively. When a high level signal is applied, each of the relay switches 101, 102, 103, and 104 turns ON.

The Q output terminal and reset terminal of the flip-flop 113 are connected to a timer circuit 115. The constitution and operation of the timer circuit 115 are the same as those of the timer circuit 54 of the first embodiment. The output of the timer circuit 115 is connected to the reset terminal of the flip-flop 113 and also to the reset terminal of the decade counter 112 via a NAND gate 116.

Another push button switch 120, used to manually reset the decade counter 112 and the flip-flop 113, is provided in this embodiment. Namely, the push button switch 120 is connected to the NAND gate 116 via a transistor 117 and a Schmitt trigger circuit 118. The driver can correct any error in the actuation of the push button switch 60 by actuating the push button switch 120, and then correctly actuating the push button switch 60 again.

A power supply circuit 119, which is the same as the power supply circuit 59 of the first embodiment, is provided in the control circuit 112.

Hereinafter, the operation of the second embodiment of FIGS. 4 and 5 will be explained.

Normally, a signal is not applied to the clock terminal of the decade counter 112 and a high level signal is produced only on the Q.sub.0 output terminal of the decade counter 112, thus only the relay switch 101 is closed. Therefore, in this case, the operation switch 10 is connected to and controls the electrically-controlled fender mirror 20.

When the push button switch 60 is actuated, for example, twice, the decade counter 112 produces a high level signal only at the Q.sub.2 output terminal, closing the relay switch 103 and connecting the operation switch 10 to the electrically-controlled front under mirror 80. Furthermore, since the flip-flop 113 is set, the timer circuit 115 starts the afore-mentioned timer operation. When the time period T has elapsed after the actuation of the push button switch 60, a signal is applied to the reset terminals of the flip-flop 113 and the decade counter 112 via the NAND gate 116, causing them to be reset. As a result, the signal at the Q.sub.2 output terminal of the decade counter 112 is inverted to a low level and a high level signal appears at the Q.sub.0 output terminal, returning the relay switch 101 to the ON state. That is, if the push button switch 60 is actuated twice, the electrically-controlled front under mirror 80 can be controlled by operating the operation switch 10 for the time period T. Where the push button switch 60 is actuated once, the relay switch 102 is closed and the electrically-controlled room mirror 30 can be controlled by the operation switch 10 for the time period T. When the push button 60 is actuated three times, the relay switch 104 is closed and the electrically-controlled rear under mirror 90 can be controlled by the operation switch 10 for the time period T. The time period T can be freely varied by changing the time constant R.sub.1 C.sub.1 of the timer circuit 115.

As will be obvious from the foregoing description, a power seat, power window, and other electrical devices can be used instead of the above-mentioned mirrors.

Many widely different embodiments of the present invention may be constructed without departing from the spirit and scope of the present invention. It should be understood that the present invention is not limited to the specific embodiments described in this specification, except as defined in the appended claims.