FR2522303A1 - Motor vehicle antitheft device with audible alarm - uses detectors on doors, bonnet and boot lid to activate electronic circuit which has delay circuits to allow entry and exit - Google Patents

Abstract

The anti-theft device uses an electronic circuit to detect unauthorised usage of the vehicle and has an electrical contact connected into the control box circuit of the vehicle to disconnect the electric circuits used to run the engine. An audible alarm is also triggered. Electric contacts are fitted to detect opening of the doors, bonnet, or boot lid of the vehicle. Additional contacts are fitted on the handbrake lever and on the accelerator cable. The electronic circuit is based on two 555 integrated circuit timers which provide timing for entry and exit delays. CMOS logic gates are used for the detector circuits, and if the alarm is activated as output transistor drives a relay operating the electrical system disabling contact.

Description

The present invention relates to anti-theft device. The technical sector of the invention is that of electro-mechanical equipment.

 The invention finds its application in the automotive field.

The application is made on diesel engine, truck or light car (black box) or gasoline or gas engine (ignition coil) .The example of the device described here is that mounted on a diesel engine.

 There are already known anti-theft devices that are triggered when trying to break into a car. On the other hand, we do not know how to obtain total security to immobilize a running or stopped motor vehicle, keys in contact, doors, doors and hood not hindered.

 It is the object of the present invention to guarantee the immobility of the vehicle. This safety is obtained both motor running and stopped.

 It is known that, in the event of a break-in, the protection of the immobilization of the vehicle is no longer ensured, whereas with the antitheft device presented, this immobilization is guaranteed.

 After the march of d; motor, the operation of the parking brake or the accelerator will cause the motor to be cut off and a delayed alarm to be triggered.

 This antitheft device equipping an installation powered by a direct current source, which device comprises an alarm, is characterized by a timed electronic control unit with personal adjustment of the alarm, the presence of a double-acting device positioned and maneuvered. by the throttle cable (25), stopped by the thrust stop (26), and which controls the black box and the electronic box, and a push button connected to the parking brake and a general switch with 3 walking positions.

The invention will be better understood on reading the following description and on the attached drawing in which:
- Figure 1 is a diagram of the device for the total security of a vehicle immobilized engine running or stopped with timed audible alarm and custom setting.

 The + of the accumulator battery (18), by the driver (29) feeds a switch (7) to three positions. This switch in position I cuts the direct supply of the normal start and contacts the mass (16) by the driver (6) of the electronic box (11).

This power supply being derived from the driver (23) which pushes through the push button of the parking brake (21), to feed the conductor (24) and end the double-acting device (10) at the point of contact (34). This point of contact (34) is permanently in contact with the point (33). The derivation obtained on the conductor (22) allows the supply of the black box (17) which allows the maintenance of the engine running.

 a) Triggering the handbrake (21) cuts off power to the conductor (24) and stops the motor.

 b) The parking brake remains pulled, so the push button (21) is contacted, the current flows in the conductor (24) to supply the device (10) to the point of contact (34). The action of the accelerator (20) decorates the contact (33), causes the motor to stop and contacts the point (32) which gives a pulse on the conductor (5); this pulse on (5) causes the electronic alarm (11), powered by the driver (2) and coming from the accumulator battery (18), to trip to ground (27), which commands 11 seconds later, via the conductor (1), the buzzer (9), connected to ground at the point (30).

 c) When opening the doors acting on the push buttons (12), (13), (14) and (15), one of the masses causes the driver (3) to trigger the electronic alarm which commands 11 seconds later, through the conductor (1), the buzzer (9) connected to ground at point (30).

 d) The opening of the cover acting on the push button (19), as well as the push button (8) of the trunk, causes via the driver (4) the immediate triggering of the electronic alarm (11), which control via the driver (1) the buzzer (9) scaled at the point (30).

 - Figure 2 is a diagram of the device for securing the immobilization of the vehicle, engine running or stopped, without the intervention of 1 audible alarm.

The + of the accumulator battery (18) by the driver (29), supplies the switch (7) with 3 positions. This switch in position II, cuts the direct supply of the normal start-up, as well as the electronic alarm by the earth conductor (16), this power supply is derived on the conductor (23) which passes by the push button handbrake (21) for powering the conductor (24) and terminates at the double acting device (10) at the point of contact (34). This contact point (34) is permanently in contact with the point (33). The derivation obtained on the conductor (22) allows the power supply of the black box (17) which makes it possible to keep the engine running.

 a) Triggering the parking brake (21) causes the power supply to be cut off on the driver (24) and the engine stops.

b) The parking brake remains pulled, so the push button (21) is contacted, the current flows in the conductor (24), to supply the double-acting device (10) at the point of contact (34), action of the accelerator disconnects the contact (33) and causes the engine to stop without causing the electronic alarm
- Figure 111 is a diagram of the device of the normal restart of the vehicle. After opening the door, a time of 11 seconds allows access to the secret switch thus neutralizing the entire security device.

 The + of the accumulator battery (18) by a conductor (29) feeds a switch (7) with 3 positions. This switch position III derives the current on the conductor (22). The direct derivation obtained allows the supply of the black box (17) by the conventional start contact (28).

PRINCIPLE OF OPERATION OF THE ELECTRONIC CIRCUIT r
The electronic system uses the circuits CD4098 and NE555 (see diagram attached)
The CD4098 includes two retractable monostable. The trigger is on the rising flank or on the descending flank.

 The duration of the output pulse is determined by the circuit C.R.

outside.

The truth table below provides a better understanding of the operating principle

<tb><SEP> During <SEP> the <SEP> time <SEP> of <SEP> the impulse
<tb> pins <SEP> 12 <SEP> 11 <SEP> 13 <SEP> 10 <SEP>:
<tb> States <SEP> x <SEP> x <SEP> O <SEP> 0
<tb> logical <SEP> 0 <SEP> 1 <SEP> 1 <SEP> 0
<tb><SEP> 0 <SEP>#<SEP> 1 <SEP><SEP> 1 <SEP> 1
<tb><SEP> 0 <SEP><SEP> 1 # 0 <SEP> 1 <SEP><SEP> 1
<Tb>
x = conductor (V) in contact (32) of the diagram Figure 1, 2 and 3.

The two NE555s are mounted oscillator and monostable.

On power-up, the monostable NE555 delivers logic 1 to logical O by the inverter CD4011 for the duration calculated at 12 seconds. After this time, the set NE555 and CD4011 goes to the logical state 1 which allows both monostable circuit CD4098 to be active. If the "Gate" input (III) goes to logic state 0 (grounding), the output 10 goes to logic state 1 (see table) whose duration is approximately 11 seconds. After this time, it returns to state 0. If the mass of the power supply is not cut off before these seconds, a logic pulse O is transmitted to the input 5 of the second monostable. The output is active for one minute and 30 seconds which allows the NE555, oscillator mounted and whose duty cycle can be changed by the 5OKiloohms potentiometer, to make the relay active.

 The transistor 2N2222 allows an adaptation between the power delivered by the oscillator and the power consumed by the relay.

The entry "mallelflt? Froncticnne ~ in the same way as the entry" Door "(III).

If the input "x" (V) goes to logic state 1 (powering up to 12V). The output passes logic state 1 for 11 seconds. If no power failure occurs before 11 seconds, the output returns to O and sends a 0 pulse to the second monostable. It is active for one minute and thirty seconds.

So the oscillator NE555 goes into operating state as well as the relay.

If the input "Cover" (IV) changes to logic 0, the inverter CD4011 transmits a logic state 1 to the input (4) of the second monostable. According to the truth table of the monostable output goes to state 1 during the delay time, ie one minute and thirty seconds
Which causes the oscillation of the relay,
The + 12 V supply is via the input lug 11.

Claims (4)

1 / Antitheft device equipping an installation powered by a direct current source, which device comprises an alarm, characterized in that the power supply of the original black electronic box is provided with a power failure - 1 ' Engine shutdown, opening of the doors, hood, and trunk excite an electronic box triggering a buzzer. 2 / Apparatus according to claim 1 characterized in that said current cutoff neutralizes the original black box of diesel, causing 1 stop supply of the hydraulic pump and thus the engine stop. 3 / Apparatus according to any one of claims 1 and 2 characterized in that said cut is installed under the bonnet and on the throttle cable - this cut is materialalled by a double-acting switch; a second switch, placed on the support of the parking brake, reinforces the action of the first contactor. 4 / Antitheft device used for the protection of an automobile, characterized by the contact of the push button of the ceiling lamp controlled by the opening of the doors or the trunk, as well as a button pusher added under the bonnet. One of the maneuvers causes the excitation of the electronic box which triggers the delayed alarm.