JPS5822740A - Time limiting power source for automobile - Google Patents

Abstract

PURPOSE:To omit the labor of making ON again an ignition key to operate a load by providing a time limiting power supply system for supplying power to a load such as a powdered window or the like for the prescribed period even after the key is made OFF in the system for an automobile. CONSTITUTION:A time limiting power source has three types of power source systems such as a battery direct-coupling system P1, a key switch system P2 for energizing only during the period of closing a key switch KS, and a time limiting system P3 for energizing during the prescribed period even after the switch KS is opened. When the key switch KS is closed, a current flows in a circuit of BT, RL2 and TR. Accordingly, the relay RL2 is driven to close a make contact M2. Thus, a load from the system P3 to the powered window starts being energized. When a switch KS is opened, a current to a transistor TR is eliminated, but since a capacity C and resistors R2, R3 form a discharge time constant type timer TIM, it maintains ON for the prescribed period, and the window which is forgotten to be closed is closed. Thereafter, the transistor TR is deenergized, causing the contact M2 to be opened.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a time-limited power supply device for an automobile that supplies power to a load for a certain period of time even after the ignition key is turned off.

In general, power supplies for automobiles are broadly divided into battery, battery direct connection systems, and key switch systems depending on the nature of the load.

The battery direct connection system constantly supplies power as long as the battery is connected, and the loads include clocks, room lamps, etc. On the other hand, the key switch and key switch systems only supply power while the key switch is on.
This applies to general loads such as engine ignition systems, radio receivers, etc.

By the way, some of the latest car equipment includes power windows,
The number of electrically operated equipment called power seats is increasing, and drivers often try to operate these when exiting the vehicle. In this case, if the power supply system for these facilities is the above-mentioned key switch system, they cannot be operated with the ignition key turned off, so it becomes necessary to turn on the emblem key again just before getting off the vehicle. Such a problem would not occur if power was supplied from a system directly connected to the battery, but considering the special environment of an automobile, it is preferable that power cannot be supplied to the load as much as possible when the vehicle is unattended.

The present invention aims to provide a time-limited power supply device for automobiles that can meet these demands, and its features include a relay in which a make contact is interposed in the power line from the battery to the load, and an ignition switch.

A driver is provided that always drives the relay while the key switch is on, and a timer that energizes the driver for a certain period of time even after the key switch is turned off. The problem lies in the fact that multiple loads are connected.

This will be explained in detail below with reference to illustrated embodiments.

1 and 2 are circuit diagrams and waveform diagrams showing an embodiment of the present invention, and the part within the broken line in FIG. 1 is a time-limited power supply device.

FIG. 1 shows three types of power supply systems. The first is a battery direct connection system P! that supplies power directly from the battery BT to the load (usually via a heater). It is. The second is Igni,
Key switch system P that supplies power only while the key switch KS, which is linked to the key, is on! It is. This strain pt
Generally, a switch KS drives relay RLl'i, and power is supplied to the load through its make contact M+k. The third time-limited system Ps is according to the present invention, and as shown in FIG. 2, power is supplied to the load for a certain period T even after the key switch and the switch KS are turned off.

In the circuit example shown in Fig. 1, when the key switch and the switch are turned on, the capacitor C is immediately charged from the battery BT through the key switch, the switch KS, the diode D1, and the resistor R1k, and the capacitor C is charged immediately through the resistor Rt.
A pace current is supplied to the transistor (relay driver) TH through. As a result, transistor TR is turned on and current flows through the BT-RLI-TR path. For this reason, relay RL.

is driven and the make contact Mt? Timed system P3 as it closes
From there, power supply to multiple loads such as power windows is started. Rutoha and Teri B turn off the key switch KS.
Although the base current is no longer supplied from T to the transistor TR, since the capacitor C and the resistors R1e and R8 constitute a discharge time constant type timer TrMi, the transistor TR and the relay RL remain in the ON state for a certain period of time. For this reason, if the period Ti is set to, for example, about 5 to 60 seconds, it is possible to close, for example, a power window type window that you forgot to close during this time. Then, after the period has elapsed, the transistor TR is turned off and the contact island is opened, so that there is no possibility that power will be supplied to the load from the time-limited system pm thereafter.

As described above, according to the present invention, it is possible to ignite a load that generally needs to be operated just before getting off the vehicle.

Power is supplied for a certain period of time even after the main key is turned off, so
This eliminates the need to turn on the keys again to activate these loads. Furthermore, since power cannot be supplied to such a load after the expiration of the specified period, it is safe even when the vehicle is left unattended.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, and FIG. 2 is a waveform diagram of each part. In the figure, TIM is a timer, TR is a transistor (driver), RL is a beam relay, pigeon is its make contact, BT is a battery, and Ps is a time limit system. Applicant Fujitsu Ten Ltd. Representative Patent Attorney Minoru Yanagi Figure 1 2 dents 23j-1111±- ■

Claims (1)

[Claims] A relay with all make contacts in the power line from the battery to the load, a driver that always drives the relay while the ignition switch, switch switch, and switch are on, and a driver that always drives the relay while the ignition switch, switch switch, and switch are turned off. 2. A time-limited power supply device for an automobile, characterized in that the timer includes a timer that energizes the driver for a certain period of time thereafter, and a plurality of loads are connected to the power supply line.