WO2001054951A1

WO2001054951A1 - Mains-connected vehicle apparatus

Info

Publication number: WO2001054951A1
Application number: PCT/SE2001/000151
Authority: WO
Inventors: Jan Ruus
Original assignee: Calix Ab
Priority date: 2000-01-25
Filing date: 2001-01-25
Publication date: 2001-08-02
Also published as: AU2001230680A1

Abstract

An electrical indicator or alarm circuit for a vehicle can detect whether a vehicle is connected to alternating mains voltage. To do this there is a control circuit (11), which has an output connection connected to an alarm means (33, 31), and which is also connected to one end of an electrical influence conductor (9). An alternating voltage is induced or formed capacitively in the influence conductor when the vehicle is connected to the electrical mains supply network, by virtue of the fact that the influence conductor lies close to the mains conductor (7) in the vehicle. The influence voltage formed can be detected by the control circuit by virtue of the fact that the other end of the influence conductor is not connected to any electrically conducting component and has high resistance to such electrically conducting components. When the influence voltage is detected, a signal can be provided on a line (13) to a warning light, for example, so that it is turned on. The circuit can also detect whether the vehicle ignition system (29, 32) has been turned on and if this is the case and there is influence voltage at the same time, to trigger an alarm, e.g. an acoustic alarm (31).

Description

Mains-connected vehicle apparatus

Technical field

The present invention relates to the mains-connected vehicle apparatus and to a protective or warning device for a vehicle for connection to a mains voltage.

Background of the invention

A vehicle can contain various apparatuses, such as apparatuses for heating the vehicle and battery chargers. Such an apparatus can be driven by current from a distribution network, such as the electrical mains network, by connecting a mains cable to an inlet on the vehicle. When the vehicle is driven, there is the risk that the driver of the vehicle will forget to uncouple the mains line from the vehicle. This can result in the destruction of the cable or the inlet on the vehicle or even a portion of the vehicle to which the inlet is fixed. This is especially liable to occur when using electrically operated heating devices, such as passenger compartment heaters and engine heaters, since these are usually turned on for a period prior to driving the vehicle.

Description of the invention

One purpose of the present invention is to provide a device for indicating and/or sounding an alarm, when a mains voltage is connected to the vehicle.

It is a further purpose of the invention to provide such a device which provides such an indication and/or alarm only when the vehicle is started.

It is a further purpose of the invention to provide a monitoring device which can automatically disconnect an apparatus driven electrically by the battery voltage, such as a car heater with electrical control or the ignition system of the motor vehicle, when the vehicle is connected to the mains voltage. An electrical indicator or alarm circuit for a vehicle comprises a control circuit with an outlet connector coupled to an alarm means for other devices. The vehicle has a mains connection to alternating voltage of an electrical supply network to drive, for example, a heating device in the vehicle. The control circuit is also joined to an electrical influence conductor. The influence conductor can be the coil in a relay in a relay box for turning on or off a heating device, but in general it can be a conductor placed close to or next to a conductor which, when the mains connector is connected, is sure to have an alternating voltage and, when the mains connection is disconnected, does not have any alternating voltage. In the influence conductor an alternating voltage is generated by electrical influence when the mains alternating voltage is connected to the vehicle coupled the electrical supply network, by transference from a conductor for mains voltage located in the vicinity of the influence conductor. The influence voltage formed is detected by the control circuit, which can then trigger the alarm means or provide another indication.

Description of the figures

The invention will now be described in connection with two non-limiting examples with reference to the drawings, in which: Figure 1 is a circuit diagram of parts of the electrical system of a motor vehicle, related to the operation and control of vehicle heating devices,

Figure 2 is a circuit diagram of parts of the electrical system, in this case related to the connection of a battery charger in the vehicle to the alternating voltage mains.

Description of preferred embodiments

Figure 1 shows a circuit diagram for a vehicle electrical system. The diagram shows components essential for connecting devices such as car heaters and engine heaters. One such heater of resistive type is shown with the resistance at 1 in Fig. 1 driven by electric current from the mains, e.g. the mains electrical distribution network. The engagement of this or these mains driven device(s) is controlled by a micro-control circuit 5 driven by electric current from the vehicle starter battery 7, the negative pole of which is conventionally coupled to the vehicle earth. The micro-control circuit 5 can suitably include timer means and be programmed to turn on and off the supply of mains current to the device 1 at predetermined points in time.

The electrical mains voltage is connected to the vehicle via a cable 9 with the coupling shown at 11 to a relay box 13. In the relay box there are lines between the poles of the inlet for active conductors (not earth conductors) and outlet connections shown at 15 to the resistive heater 1. In one of these lines there is a switch, which is a relay contact 17 of an electrical relay, the coil or solenoid being shown at 19. The relay coil 19 has low resistance and is connected at one end to earth via a diode 21, the positive electrode of which is connected to the coil. The other end of the relay coil is connected to the positive voltage from the starting battery 7 via an electronics box 23, which, i.a. contains the micro-control circuit 5. The other end of the coil is also connected to an input II of the micro-control circuit.

In the relay box 13 a portion of any incoming mains current can be transferred to the relay coil 19 inductively and/or capacitrvely. Such a transference takes place normally in the relay box 13 by virtue of the fact that the line with the main voltage lies close to the solenoid. If this transference is not sufficient, a special transference arrangement is used consisting of two conductors, not shown, each from one of the two poles of the mains voltage and having free ends. Such conductors can be wound around the coil 19 and possibly inside the coil layers, but of course electrically insulated from the coil windings. When the mains voltage is active and there is an alternating current in one of said lines, a voltage stemming from this alternating current will arise in the coil winding. This voltage can be called an influence voltage and is rather small, typically a maximum of a few hundred mV. When the relay is activated, the influence voltage cannot be detected simply, since it is then superimposed on the voltage applied, as controlled by the electronics box 23, over the coil from the battery 7 for operating the resistive heater 1, said voltage being approximately 6, 12 or 24 V for common types of batteries. The electrical circuits of the electronics box 23, such as the micro-control circuit 5, receive their operating voltage from the battery 7. The positive pole of the batteries connected to the relay pole 19 via an electric switch controlled by the micro-control circuit 5, in this case shown as a PNP transistor 25, to the emitter of which the battery voltage is connected. The collector of the transistor is joined to a connection to the relay box, more particularly the connection to the relay coil 19. A base of the transistor 25 is directly joined to an output 01 of the micro-control circuit 5. When the base is supplied with current from the micro-control circuit output 01, current from the battery 7 can pass through the transistor 25 and through the relay coil 19. When current flows through the relay coil, the relay switch 17 closes so that the heater 1 is supplied with electric current from the mains and it begins its resistive heating.

If the mains voltage is coupled to the relay box 13 and the switch 25, after having been in a closed state, is opened so that the coil winding 19 is no longer supplied with current from the battery 7, there will only be the influence voltage in the coil winding and the voltage induced by the self-inductance of the coil. This latter voltage will rapidly dissipate, with the negative induced voltage being diverted to earth via a "free wheeling" diode 47 coupled between the battery connector of the coil winding and earth, so that only the influence voltage will then remain. By virtue of the fact that the diode 21 functions as an interruption for small voltages over the diode, the influence voltage, now also at the input II of the micro-control circuit, will be detectable. If the mains voltage is not coupled, there will be no such detectable transfer voltage.

The micro-control circuit 5 also has an input 12 coupled to an electric switch 29 for various apparatus driven by the vehicle battery 7, here shown at 30. This switch can be a first position of the ignition key switch of the motor vehicle. A second input 13 can be coupled to the vehicle ignition system shown at 32. By evaluating the signal at the input 12, the control circuit 5 can then determine whether the vehicle is probably about to be driven or, from the signal at the input 13, whether the ignition system is turned on and thus the vehicle engine is probably running or in any case about to be started. When either of these states is detected, the resistive heater 1 is turned off by sending an appropriate signal to the switch 25 from the micro-control circuit, thereby deactivating the relay. If, at the same time as one of these states, an influence voltage is detected at the input II to the micro-control circuit, this means that there is a mains voltage and, consequently, the cable 9 is coupled to the vehicle, and the micro-control circuit 5 can trigger an alarm, by providing an optical signal with the aid of a light source 33, for example in the form of a lamp on the vehicle instrument panel and/or by generating audible signals from a speaker or siren 31, by supplying electric voltage to the outputs 02 and 03. Such an alarm, particularly with audible signals, is preferably sounded when the micro-control circuit determines that mains voltage is coupled to the relay box 13 and at the same time as the vehicle in all certainty will begin to move and/or that the vehicle ignition system is turned on. The alarm can then inform the user or the driver of the vehicle or some other person in the vicinity of the vehicle that the external mains connector is still connected and that the mains cable must be removed prior to driving the vehicle. The lamp 33 can with advantage always be lit with a steady light for example, as soon as both the mains voltage is present and the switch 29 is closed and changed to a blinking mode when the ignition system 32 is turned on as well. The switch of the ignition system is shown at 35, which is conventionally closed by turning the ignition key to a second or innermost position. When this switch has been closed, the starter motor relay 37 is activated so that the starter motor 35 is supplied with electric current direct from the battery 7. The switch 35 can be coupled in series with an additional switch 41, which is controlled by a signal sent by the micro-control unit 5 at output 05. When the ignition key is then moved to its first position, corresponding to closing the switch 29, the micro-control unit can sense whether the mains voltage is also coupled in and in this case send a signal to open the switch 41, so that the starter motor, and thus the vehicle engine, cannot be started. Otherwise, a signal is sent to the switch 41 so that it can be closed and the starter motor can be operated. As an alternative to the switch 41, the signal can be sent directly to the ignition system 32 to turn it off as soon as the micro-control unit 5 detects that there is mains voltage. The vehicle can also be provided with a fuel-powered heater 43, which is activated by a small current supplied from the battery 7 to drive a small fuel pump and ignition plug. Connecting the fuel-powered heater 43 to the battery is done with the aid of a switch or relay 45, which in the embodiment shown in Fig. 1 is also controlled by the micro-control unit 5 by virtue of the fact that the control input of the switch is connected to the output 04 from the micro-control unit. The micro-control circuit 5 is suitably programmed so that when the vehicle is not to be heated, it will leave the relay contact 17 of the relay in the relay box open and control the switch 45 to its open position so that both heaters 1 and 43 will not be activated. Furthermore, the micro- control circuit, when its built-in timer circuit (not shown) generates a signal that heating of the vehicle is to be initiated, and at the same time the micro-control circuit detects at its input II that the mains voltage is plugged in, the transistor switch 25 switches to its closed position for activating the relay in the relay box 13 and closing its relay contact 17 so that the resistive heater 1 is supplied with mains voltage and thus begins to heat the vehicle, and to keep the switch 45 in its open position. If, instead, the micro-control circuit detects that the mains voltage has not been plugged in, a signal is sent from the output 05 to move the switch 45 to its closed position to use the fuel-powered heater 43 to heat the vehicle and the transistor switch 25 will remain in its open position.

Instead of using an output 01 for controlling the switch 25 and a separate input II for detecting any influence voltage, instead of the line to the input II, the output and control input of the transistor switch, i.e. its collector and base, can instead be coupled to each other in such a manner that any alternating current component at the output electrode is transfeπed to the control electrode. This connection can be effected, for example by means of a capacitor 27 as shown in the Figure with dashed lines or with a suitably dimensioned resistance. The coupling to the micro-control circuit will in this case be to a combined I/O input.

Fig. 2 shows a circuit diagram of a more general application of the idea of the invention, in this specific case showing the mains outlet coupled to a battery charger 6 for charging the vehicle batter/ 7. Components corresponding to those in Fig. 1 have been given the same reference numerals, and will not be described in more detail here. As can be seen in the drawing, the battery charger 6 is coupled via a mains cable and intake 11 to the mains voltage. From the intake 11 there are wires 18 leading to the apparatus, which in this case is a battery charger 6. Adjacent these wires there is an arrangement 20 which transfers, by wireless influence, any incoming mains voltage to an input on the micro-control circuit 5. Such a transfer device can be regarded as a high ohm probe and can in practice be a conductor arranged along the two wires 18 but electrically insulated therefrom. In order for sufficient transfer voltage to be obtained, the wires 18 for the mains voltage may need to be in the form of a coil with the transfer conductor arranged in the coil. In certain cases, the transfer arrangement 20 only needs to cooperate with one of the wires, if, for example, due to the design of the vehicle mounted inlet cooperating with the cable plug, it is always the same conductor which has the electric phase, or, if in other case it can be assumed that the neutral conductor will always carry a component of alternating voltage.

The transfer arrangement or probe 20 in the form of a single conductor can have one end opened, i.e. not connected to any electrically conducting component or it may possibly be connected to the vehicle earth via a large resistor (not shown). The other end is connected to the input II of the micro-control circuit 5. The micro-control circuit can detect at this input, as in the case described in connection with Fig. 1, whether there is an alternating cuπent at the input stemming from the probe conductor, and thereby determine whether the mains voltage is coupled in and a cable 3 is thus connected to the vehicle. The control circuit 5 will, in this case as well, via an output 02 turn on a light source 33 as an indicator light on the vehicle instrument panel to show that the mains connection has been coupled. The audible alarm signal 31 and/or the blinking of the light 33 can be programmed to function as described in connection with Fig. 1. It will also be understood that the present invention is also very applicable for use with mobile homes or other trailers, for example, which are periodically connected to mains outlets.

Claims

1. Electrical indicator or alarm circuit for a vehicle, having a mains connector (11) to alternating voltage of an electrical distribution network, said indicator or alarm circuit comprising a control circuit with an output connection to an apparatus, indicator or alarm means controlled by said control circuit, characterized by an electrical influence conductor (19; 20) which is directly electrically joined to the control circuit (5) and electrically insulated from, but magnetically wirelessly coupled to, a conductor (18) electrically connected to the electrical distribution network for influence transferring to the influence conductor (19; 20) an alternating voltage detectable by the control circuit, when the mains connector is coupled to the electrical distribution network, to prompt the control circuit to provide a signal at its output connection to control or turn off or on the apparatus, indicator or alarm means when the mains connector is connected.

2. Electrical indicator or alarm circuit according to Claim 1, characterized in that the influence conductor includes the conductor in a relay coil (19) for a relay for connecting the mains voltage to an electric device (1).

3. Electrical indicator or alarm circuit according to Claim 3, characterized in that the relay coil has a first connection connected to earth and a second connection connected to the control circuit (5).

4. Electrical indicator or alarm circuit according to Claim 3, characterized in that the first connection of the relay coil (19) is connected to earth via a diode (21) so that when the relay coil is not supplied with current from the battery and the mains voltage is connected, only the influence voltage is in the relay coil.

5. Electrical indicator or alarm circuit according to Claim 4, characterized in that the control circuit is connected to the vehicle ignition system to detect when said system is turned on and is disposed to provide a signal at its outlet connection to the apparatus, indicator or alarm means only when the mains connection is connected and the control circuit detects at the same time that the ignition system is turned on.

6. Electrical indicator or alarm circuit according to Claim 4, characterized in that the second connection of the relay coil to the control circuit is made via a shunt past a switch (25) controlled by the control circuit for controlled supply of cirrrent to the relay coil from the vehicle battery (7).

7. Electrical indicator or alarm circuit according to Claim 6, characterized in that the shunt comprises a capacitor (27) or resistor.

8. Electrical indicator or alarm circuit according to Claim 1, characterized in that the influence conductor is a simple electric conductor (20) arranged next to and electrically insulated from, the conductor connected to the mains connection.