JPH04110874U - Transmitter for keyless entry system - Google Patents

Abstract

(57) [Summary] [Purpose] Regarding the power supply circuit of a transmitter for a keyless entry system that remotely controls a vehicle door lock, the present invention aims to eliminate the unnecessary consumption of power by transmitting a signal while the transmitter switch is operated. Improved. [Structure] The positive electrode of the battery 11 is connected to the emitter terminal of a transistor 12, and the collector terminal of the transistor 12 is connected to the power supply of each circuit as a Vcc voltage. The base terminal of the transistor 12 is connected to one end of a switch 16 through a resistor 13 and a capacitor 15.
A resistor 14 is connected in parallel with . The other end of the switch 16 is connected to the cathode of the battery 11 and grounded.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is a so-called keyless entry system that wirelessly remotely controls vehicle locking devices. The present invention relates to a structure for reducing power consumption in a system transmitter.

0002

[Conventional technology]

Previously, keyless entry systems that wirelessly remotely control vehicle locking devices were used. A portable transmitter sends out an encrypted code on a radio signal that is installed in the vehicle. The receiver receives this and determines the pass/fail of the signal, and if it matches the code, it locks the device. was activated, and if it did not match, it was not activated. Here, the sending code is stored in PROM (Programming Read Only Memory). ), the code will be saved as long as you operate the transmitter switch. The signal continued to be output repeatedly. In contrast, the receiver installed in the vehicle receives the code signal output from the transmitter a predetermined number of times. When received, it is determined whether the signal is accepted as a legitimate signal and a pre-registered encryption code is used. When a match was made, the solenoid was activated to unlock the door.

0003

[Problem that the idea aims to solve]

Therefore, if you keep the transmitter switch on for longer than the time required for the receiver to make a decision, If you operate it, the code signal will continue to be sent, consuming unnecessary power. there was. Therefore, the present invention is a keyless entry system using a PROM that stores a PIN code. Even if you keep pressing the transmit switch on the device's transmitter, the code signal will not be output for more than the specified time. The purpose is to provide no transmitter.

0004

[Means to solve the problem]

This invention provides a keyless entry system for remote control of vehicle door locks. In the power supply circuit of the transmitter, power is supplied by operating the PIN code output switch. the transistor to operate and maintain the ON state of the transistor for a predetermined period of time. A timer circuit is provided.

[0005]

[Effect]

According to the present invention, a transmitter for a keyless entry system can be used to remotely lock a vehicle door. When operating, if the transistor is turned on by operating the transmitter switch, Power is supplied to each circuit within the transmitter, and at the same time the timer circuit starts working. stop When a predetermined period of time has elapsed, the transistor automatically turns off, thereby reducing power supply. Supply is cut off. At this time, while the power is on, the receiver side of the vehicle judges whether the signal is valid or not. Even if you operate the transmitter switch for longer than necessary, The power turns off automatically to prevent unnecessary battery consumption.

[0006]

【Example】

Next, the present invention will be explained with reference to FIGS. 1 and 2. Figure 2 shows the circuit configuration of a keyless entry transmitter using PROM. FIG. The oscillation circuit 20 oscillates a clock signal and sends this oscillation signal to the code storage section 30. input. In the code storage unit 30, an encryption code corresponding one-to-one with the receiver side is stored in the PROM. It is stored in advance, and a code signal is output by adding the clock signal here. and inputs it to the FM modulation circuit 40. In the FM modulation circuit 40, the input code signal applies FM modulation to the carrier wave. stop This is then input to the final stage output circuit 50. The output circuit 50 emits the FM modulated carrier wave as a radio wave from an antenna 60. shoot

[0007] Figure 1 shows a power supply circuit that supplies power to each circuit in Figure 2, which is the key point of this invention. . Next, the configuration of this power supply circuit will be explained. The positive electrode of the battery 11 is connected to the emitter terminal of the transistor 12, and the transistor The collector terminal of the converter 12 is connected to the power supply of each circuit as a Vcc voltage. transition The base terminal of the star 12 is connected to the transmission switch 16 through a resistor 13 and a capacitor 15. A resistor 14 is connected in parallel with the capacitor 15. Sending speed The other end of the switch 16 is connected to the negative electrode of the battery 11 and grounded.

[0008] The operation of the power supply circuit configured as described above will be described. When the switch 16 in the OFF state is turned ON, the battery 11, the transistor 12, There is a closed circuit of resistors 13 and 14, capacitor 15, switch 16, and battery 11. Wear. In this circuit, the charge must flow for a predetermined time while the charge is accumulated in the capacitor 15. The source current turns on transistor 12 and supplies power to each circuit within the transmitter. So After the predetermined time has elapsed, the transistor 12 only needs to remain on. The source current stops flowing and the transistor 12 is turned off. Therefore, at a given time It works as a timer that turns on the transistor only for a certain period of time. At this time, when only the resistor 13 is used, the transistor 12 is turned on, but the resistor 13 and the resistor 14 so that the transistor 12 does not turn on. Set the value of resistor 14 in advance.

[0009] Next, when the switch 16 is turned off, the capacitor 15 is discharged through the resistor 14. and return to the initial state. Therefore, after the switch 16 is turned on, the resistor 13 Until a predetermined time determined by resistor 14 and capacitor 15, the power supply circuit is connected to each circuit of the entire transmitter. The device will continue to supply power and output pin code signals. As mentioned above, even if you keep pressing the transmitter switch, the transmitter will automatically turn off after a certain period of time. Since the power is turned OFF when the button is pressed, unnecessary consumption of the battery due to continuous pressing can be prevented. .

0010

[Effect of the idea]

According to the present invention, the transmitter of the keyless entry system can lock the vehicle door. When performing remote control, if the time required for the receiving side to judge whether the signal is acceptable or not is exceeded. Even if you press the transmitter switch again, the timer circuit works in the transmitter and the specified time elapses. Since the power will be automatically cut off if the It can be used for a long time.

[Brief explanation of drawings]

FIG. 1 is a power supply circuit diagram according to the present invention.

FIG. 2 is a block diagram of a transmitter for a keyless entry system.

[Explanation of symbols]

11 Battery 12 Transistor 15 Capacitor 16 switch

Claims (1)

[Scope of utility model registration request] 1. In a power supply circuit of a transmitter for a keyless entry system for remotely controlling a vehicle door lock, a transistor is activated to supply power by operating a password transmission switch, and the transistor is maintained in an ON state for a predetermined period of time. 1. A transmitter for a keyless entry system, characterized by being provided with a timer circuit that performs the following operations.