GB2319653A

GB2319653A - Security Battery

Info

Publication number: GB2319653A
Application number: GB9624395A
Authority: GB
Inventors: Peter Phillip Gatehouse
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-11-23
Filing date: 1996-11-23
Publication date: 1998-05-27
Anticipated expiration: 2016-11-23
Also published as: GB9624395D0; GB2319653B

Abstract

A battery has an exposed negative terminal 2, but the positive terminal 10 is hidden within the casing of the battery, and instead only a dummy terminal 3 is visible. This is connected to the real positive terminal 10 via a normally closed heavy duty switch, such as a solenoid 9. An electronic control board, 8 senses any unauthorised attempt to start the vehicle via voltage changes at terminials 4 or 5 or the volt drop detector 17 in the stand alone version. The resultant change of output voltage from the control board 8, operates the solenoid 9, thus removing the main power available from the battery, and preventing the engine from being started. To prevent radio codes from being lost a small by-pass circuit 14 allows a small amount of current to be drawn from dummy terminal 3. The authorised user has a key fob transmitter which is pressed on approaching the vehicle. A receiver 7 inside the battery receives the signal and inhibits the solenoid 9, so full power is always available until the completion of the journey. When the ignition is then switched off the battery reverts automatically to standby mode after a pre-determined time.

Description

SECURITY BATTERY It is well known that most motor vehicles are started by means of a starter motor and an ignition spark, where applicable. The power source for starting is usually provided by the starter battery contained in the vehicle. The battery can be switched in and out of circuit by way of an ignition key.

This system is very poor however in terms of security of the vehicle. A thief can use jump leads to by-pass the ignition switch to enable him to steal a vehicle quite easily, and this fact is confirmed by the enormous number of thefts each year, not only of motor-cars, but motor-cycles and even boats. There is obviously a requirement for an immobiliser which will prevent theft by this means.

There are now available various devices which are designed to act as a deterrent to a potential thief. In many existing arrangements, the device removes power from the ignition coil, the starter motor solenoid, or in the case of diesel engines the fuel stop solenoid. This may prevent hot-wiring from the driver's compartment but once the bonnet is raised, the thief has access to the engine compartment, and can by-pass the device by wiring direct from the positive terminal of the battery.

What is required is a battery in the vehicle which can be switched off internally so that no power is available at the positive terminal, unless it receives an external coded signal from the authorised user.

Patents have already been granted for such a battery; U.K. PATENT No.2268620 on 19 July 1995 and U.S.A.PATENT No.5498486 on 12 march 1996.

The original patent applications were filed as No.9214014 on 19 July 1992 and as No. 9301734 on 20 January 1993.

Since that time, various modifications, and improvements have been made, some to assist in marketing, and some to give cost-savings in production techniques.

As it is now too late to claim priority data, the inventor is submitting a new patent application.

According to the present invention there is provided a starter battery suitable for automotive vehicles, the battery having positive and negative terminals, but incorporating a control circuit sealed within the battery, including in particular, a heavy duty switch between the positive terminal and a dummy terminal.

It is important to note that the real positive terminal is integrated inside the battery and is not accessible from the exterior. The dummy terminal is however accessible from the exterior and to all appearances acts as a positive terminal, with a terminal post to connect to the starter motor and other auxiliary circuits. The negative terminal post is connected in the ordinary way as a normal battery.

The control circuit within the battery is designed to control the operating of the heavy duty switch, which is normally closed, such that if it receives a signal that there is an unauthorised attempt to start the vehicle, the switch opens,, so that the dummy terminal is now no longer connected to the real positive terminal by the switch, and there is no power available to start the vehicle.

Thus the battery has the built-in capability to make the apparent positive terminal post open circuit from the real positive terminal During the construction of the battery a tamper proof screen may be built into the lid of the battery, such that when the lid is finally welded onto the battery body, the screen is positioned in such a way that it prevents tampering with the heavy duty switch, the control circuit, or the real positive terminal. This screen could be a metal screen, and also connected to the negative terminal. It would also serve to screen the switch from external magnetic interference.

The control circuit has means of detecting unauthorised attempts at starting the vehicle, and the ways in which this is carried out , can take various forms, with a wide variety of sensors. Examples of such sensors could be, a bonnet switch, an ignition sensor, a volt drop detector, a vibration or sound transducer, a light sensitive device, or an a.c.voltage ripple detector.

The control circuit is also capable of receiving an extemal coded signal from the authorised user, to allow the vehicle to be started without inhibiting the battery.

Various methods can be used to provide the extemal signal, for instance a P.l.N.

number on a keypad, a magnetic card, or more usually a radio coded signal, operating on one of the approved frequencies for such a device.

The invention may be performed in various ways, and preferred embodiments will now be described by way of example with reference to the accompanying drawings in which, FIG. 1. shows a plan view of a battery of this invention before the lid has been welded on, giving an example of the component layout FIG.2. shows an exterior plan view of the battery after the lid has been welded on into position.

FIG.3. shows a plan view similar to that in FIG.1., but notice in this version of the battery there are no external sensors, as this is a stand-alone version which will be described separately.

FIG.4. shows by means of block schematic diagrams, various electronic circuits incorporating the components of a control circuit on a control board.

FIG.5. shows the similar control board schematic diagram, but using different sensors for the version shown in FIG.3.

FIG.6. shows a key4ob transmitter suitable for use with any version of the battery.

The battery shown in FIG.1 .prior to the lid being welded into place, the gas vent holes 1 and a normal plastic cover 11, to be welded over the battery body such that gas or liquid can only escape through the vent holes. This cover 11 forms an effective barrier between the acid and water contents in the battery and the components above the the plastic cover.

These components comprise a negative terminal 2, a real positive terminal 10, and and a dummy terminal 3. Terminal posts 3 and 10 are bridged by the plunger 9a of the solenoid 9, which forms the heavy duty switch, being normally de-energised, and therefore closed by the pressure of return spring 9b.

An electronic control board 8 is positioned above the plastic cover and has attached to it via two lead wires, two terminals 4 and 5, which are accessible from the exterior of the battery.

Referring to FIG.2. it will be seen that when a lid 6 is finally welded into place, the only accessible terminals are the negative terminal post 2, the dummy terminal post 3, and the two terminals 4 and 5.

When the battery is installed in a vehicle, the negative lead from the chassis is connected as normal to to the negative terminal post 2, The heavy duty starter motor lead and any other leads which are normally connected to the positive terminal post 10 are now connected to the dummy terminal post 3. A lead is connected to terminal 5 from the plus 12 volt d.c. terminal on the ignition coil, and a lead from a normally open bonnet switch is connected to terminal 4.

Operational procedures for using the battery will now be described by way of example and with reference to FIG. 1. to FIG.6. of the accompanying drawings.

THE NORMAL STARTING PROCEDURE. (for a battery shown in fig. ) Whilst the vehicle is nomally parked, inside the battery the control circuit board 8. is on standby awaiting an instruction or ready to sense any change in voltage from the sensor leads connected to terminals 4 and 5.. At this time the solenoid 9 is deenergised, and the powerful retum spring 9b pushes the plunger arm 9a across the gap thus bridging terminal posts 3 and 10. and allowing full power to be available from the battery. Sensor terminals 4 and 5 have an open circuit input on terminal 4, (bonnet switch closed) and a Ovolt input on terminal 5 from the igntion coil.

When the authorised user approaches the vehicle, he presses the key-fob transmitter 13 which sends a radio signal to the receiver 7 on the the control circuit board 8.The resulting output is fed to a microprocessor 12 and processed to disable the solenoid circuit for a pre-determined time, so that it cannot operate. A further output from the microprocessor energises a small sounderl 5 via a driver 15A and gives an audible "bleep" sound back to the motorist to confirm the signal has been received. This sounder could also be used as an alarm option. The motorist then climbs into the vehicle switches on the ignition and drives away in the ordinary way. If the motorist does not switch on the ignition within a pre-determined time after pressing the keyfob, the battery reverts back to standby mode automatically.

At the completion of each journey, as the ignition is switched off, a timer starts counting in the microprocessor, and after a pre-determined time, the device goes into standby mode without the motorist being obliged to press the key4ob, thus it resets automatically without any contribution from the motorist.

PROCEDURE FOR ATTEMPT TO START THE VEHICLE WITHOUT AUTHORISED SIGNAL.

If there is an attempt to start the vehicle without first sending the correct signal, the following events will take place.

1. If the thief attempts to hot-wire the ignition in the driver's compartment,the instant 12 volts is applied to the ignition coil, the battery will sense a change in input voltage from 0 volts to 12 volts at terminal 5. This will be fed into the microprocessor which will command an amplifier 16 to energise solenoid 9. This opens the heavy duty circuit between terminals 3 andl0 and the main power line to the dummy terminal 3 is broken. Thus no power is available to start the vehicle.

2. If the thief attempts to work from the engine compartment he must first raise the bonnet. The instant he raises the bonnet, the bonnet switch operates and the sensor terminal 4 senses the change of input from open-circuit to 0 volts.

This is again acted upon by the microprocessor which will again command amplifier 16 to energise solenoid 9, thus breaking the main power to terminal post 3. The solenoid 9 may act for a pre-determined time to deter the thief or it is possible to use a self-latching solenoid which would hold indefinitely until the authorised signal was received.

In the case of a normal solenoid being used, the microprocessor will generate a 12 volt pulse every few seconds with a lower holding voltage on all the time. This prevents the solenoid becoming too warm, but if shaken loose it will re-trigger within seconds. Another refinement on circuit board 8 is that when the solenoid energises and removes the main source of power from terminal 3, it would be a nuisance for motorists to also lose their radio codes and possibly engine management systems.

Accordingly there is a low powered 12 volt supply which bypasses the solenoid bridge across terminals 3 and 10. This allows a 12 volt supply to the dummy terminal post, even when the solenoid is energised, and comes in the form of a thermal fuse.

These are available with different "pass" current ratings, above which they trip out and reset when the load is removed.The thermal fuse 14 used in the circuit has a preferred value of 0.5 amps, which will not allow sufficient current to be drawn from the battery to push start the vehicle, as the ignition current required is in the order of one amp.

3. STANDALONE VERSION.

In the stand-alone version of the battery, referred to in FIG.3 and FIG.5 it can be seen that there are no external terminals 4 and 5. This version does an almost identical job as the battery shown in FIG. 1. except that it does not require external wiring connections.The electronics circuit is similar to that already described , but does not require extemal sensors because it relies on a built in voltage drop detector 17 within the battery itself, located on cicuit board 8. This is a well known circuit used in many car alarms, and relies on the fact that when any current is drawn from a battery a momentary voltage drop occurs. Accordingly, if a car-door is opened, or the ignition is switched on, or a starter motor is activated, the voltage drop is sensed and a signal is fed to the microprocessor. The resultant output signal from this is used to energise the solenoid as described previously, removing the main source of power from the battery.

The advantages of this version of the battery lay in ease of installation and costsaving. The disadvantage as far as motor cars is concerned, is that with no ignition sensor, it could be necessary to operate the key-fob on leaving the vehicle, to reset the battery to standby mode. A solution to this is to use an a.c. ripple detector circuit on the control board, plus a sound and vibrator sensor circuit whose detector is positioned near to the dummy terminal. Then, when the vehicle is started, the microprocessor is fed from the signal input from the sound detector and the a.c.

ripple circuit. The latter coming from the alternator ripple, and the former from engine sound. When the engine is switched off, both these signals cease, and the resultant signal will be processed by the microprocessor so that after a pre-determined time the battery will automatically switch back to stand-by mode without the motorist being obliged to remember to to press the key4ob on leaving the vehicle.

A further apparent disadvantage is that modern motor cars often have electric fans which can switch on for several minutes after a joumey is completed. This would register as a voltage drop and could immobilise the battery. An apparent solution to this would be to make the sensitivity of the voltage drop detector weak enough so that it would only detect a large volt drop as would be caused by the starter motor current. This would not be effective however as the vehicle could then be push started without the battery immobilising. However so long as the sounder in this version is used only as an audible feedback for the motorist, then the problem does not exist. The volt drop detector circuit can be sufficiently sensitive to operate on low current drains from the battery, such as the door opening, to detect a small voltage drop, which is far more efficient. On the few occasions that the electric fan operated after engine switch-off, even if the battery did immobilise, there would be no alarm and nobody would be aware of it. When the motorist returned to the vehicle, he would simply press the key4ob in the ordinary way and start the vehicle.

Another advantage of this version of the battery is that it will also operate in motor cycles, which at present are extremely difficult to immobilise, simply because they are so accessible. The sounder in a motor cycle version of the battery would not be used as an alarm, only to give audible feedback to the user. The volt drop detector would be designed to operate on the ignition switch on, in this case, giving immediate immobilisation of the battery.

Because it looks like an ordinary battery, with no additional wires connected to it, and no alarm sounding from it, it will not be obvious to a thief that it is not an ordinary battery.

Although schematic block diagrams are shown in FlG.4.and FIG.5, individual components are not given, but are described in sufficient detail that any competent electronics engineer could build these circuits to achieve the required results in a variety of different ways.

The most useful tool for mass production purposes is the program written for the microprocessor and allows fewer discrete components to be used, thus giving considerable cost-saving. It also allows the fig. 1 version of the battery to be shipped without the sensors detecting an alarm condition and energising the solenoid 9 thus flattening the battery. This is achieved by a special one-off fuse built into the control circuit board 8, which only blows when the battery is connected into a vehicle for the first time. This is not required for the stand-alone version of the battery.

During production testing the microprocessor 13 can also be programmed to accept a single frequency key4ob signal from the special-to-type automatic test equipment.

Only when the battery is installed in the vehicle and the afore-mentioned fuse blows, will it then respond to only one particular key4ob. This saves a great deal of time on production testing as the automatic test equipment can transmit the same coded signal for each battery on test rather than a different signal for each one. A further refinement is that the receiver 7 on the control circuit board 8 is de-activated on shipping thus saving quiescent current. It is re-activated when the battery is installed in a vehicle by switching on the ignition. The microprocessor can be programmed to allow the receiver to be switched off at any time,by using a different press button switch on the key4ob. In order to do this, a key4ob with two press-button swiches is required, which are readily available.

The key-fob transmitter 13 shown in FIG.6. is a well-known device which is readily available from a number of manufacturers. It is a low power radio transmitter which sends a digitally coded signal in one of the approved frequency bands. In the U.K.

this frequency is in the order of 418MHZ and on the continent in the order of 433MHZ. A standard device will normally have one or two press button switches18 and 19 and an L.E.D. 20 which lights when any push-button is depressed.This confirms to the user it is working.

Claims

1. A starter battery for any automotive vehicle, motor cycle, or marine craft, having positive and negative terminals, but incorporating a control circuit sealed within the battery.. This includes a heavy duty switch between the positive terminal and a dummy terminal, the positive terminal being inaccessible from the exterior of the battery, whilst the negative and dummy terminals are accessible from the exterior of the battery as terminal posts for connecting the normal positive and negative cables.

The control circuit in the battery being in tum controlled by an external device sending a coded signal to a receiver which is part of the control circuit.

2.A starter battery according to claim 1, wherein the positive terminal is connected to a dummy terminal through a switching device and a parallel circuit, allowing a small amount of current to be drawn when said switch is open.

3.A starter battery according to claim 2 , wherein the control circuit is capable of changing the status of the switching device upon receipt of an unauthorised signal to start the vehicle.

4.A starter battery according to any one of claims 1-3 wherein the said heavy duty switch is fed from a timer or microprocessor which allows the heay duty switch to operate only for a predetermined time period.

5.A starter battery according to any one of claims 1-4, wherein the heavy duty switch is in the form of a solenoid.

6.A starter battery according to any one of claims 1-5 wherein the code controlled operating device is a keyfob transmitter operating on an approved frequency, and with a receiver to match its unique code in the control circuit of the battery.

7.A starter battery according to any one of claims 1-6, wherein there is an audible sound feedback to the user to confirm a signal has been received by the receiver in the battery.

8.A starter battery according to any one of claims 1-7 wherein a tamper proof screen is installed within the battery body to protect and cover the control board, solenoid, and the real positive terminal.

9.A starter battery according to any one of claims 1-8 wherein the screen is electrically conductive, connected to the negative terminal, and also provides a magnetic screen as well.

1 0.A starter battery similar to the one described by any one of claims 1-9 wherein there are no external sensor terminals on the exterior of the battery. This is a stand alone version as described, using drawings Fig.3 and Fig.5, and using a volt drop detector circuit on the control board of the battery as a sensor to detect unauthorised starting of the vehicle.

1 A starter battery according to any one of claims 1-10 wherein sensors are provided in the control circuit board. These could be in the form of sound sensors, vibration sensors, volt drop detectors, a.c. voltage detectors, or a wide variety of other sensors, to detect an unauthorised attempt to start the vehicle, and thus operate the solenoid to prevent this.

12.A starter battery according to any one of claims 1-11 wherein the receiver may be switched off by a signal from the keyfob to save quiescent current, in case of a long storage period.

13.A starter battery substantially as herein described with reference to the accompanying drawings.