WO2011057352A1

WO2011057352A1 - An electrical supply system

Info

Publication number: WO2011057352A1
Application number: PCT/AU2010/001522
Authority: WO
Inventors: John Han
Original assignee: Skoot Logistics Australia Pty Limited; Shanghai Yongming Electronic Corporation Ltd (Symec)
Priority date: 2009-11-13
Filing date: 2010-11-15
Publication date: 2011-05-19
Also published as: AU2010317601A1

Abstract

An electrical supply system for use with a motor scooter having an illuminated display means, the system including an input electrical power supply, a rectifier to convert the input power to direct current, a battery to store extra power when voltage from the rectifier is in excess of that necessary and to supply voltage when voltage is required, a switch mode power supply and AC/DC converter to convert low DC voltage to high AC voltage and stabilise the power supply to the illuminated display means.

Description

AN ELECTRICAL SUPPLY SYSTEM

Field of the Invention.

The present invention relates to . electrical supply systems and particularly to electrical supply systems for mobile vehicles.

Background Art

An electrical power source of 150cc scooter consists of an alternator, rectifier, battery, cables and switchers. The rectifier converts alternating current (AC) generated by alternator into direct current (DC) in order to supply electrical power for the following devices of a scooter:

i) Lamps (front lamp, rear lamp, direction lamp and hazard lamp) ii) speedometer

iii) ignition

iv) battery

The alternator and rectifier are key elements of electrical power supply for a scooter. The value of output current and voltage from the alternator depends on cutting speed of magnet flux by stator coils. The speed range of the motor scooter can vary between 1500 τ/m to 7500 r/m. Therefore, the electrical power generated changed from time to time.

The battery plays an important role in the electrical power system. It becomes a buffer to store extra power when voltage from the rectifier is higher. It discharges when voltage is lower. Most of the time the motorbike does not require a strong electrical power from the alternator as it contributes more heat onto the rectifier. These facts contribute a varied voltage value on the electrical power system of a motor scooter especially at the times when the motor scooter starts and when it is running at low speed.

The provision of an illuminated container or container with illuminated display means at the rear of a motor scooter introduces an innovative outdoor mobile media particularly for food or drink delivery. When an illuminated display means is introduced, it not only requires an extra electrical power but also a stable voltage supply system to ensure that the illuminated display means works well and consistently.

It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country.

Summary of the Invention.

The present invention is directed to an electrical supply system, which may at least partially overcome at least one of the abovementioned disadvantages or provide the consumer with a useful or commercial choice.

With the foregoing in view, the present invention in one form, resides broadly in an electrical supply system for use with a motor scooter having an transportable container mounted thereto arid which draws a power load, the system including an input electrical power supply, a rectifier to convert the input power to direct current, a battery to store extra power when voltage from the rectifier is in excess of that necessary and to supply voltage when voltage is required, a switch mode power supply and AC/DC converter to convert low DC voltage to high AG . voltage and stabilise the power supply to the illuminated display means.

The illuminated display means will typically increase the load on the power supply system in excess of that which the conventional scooter power supply means is capable of creating. Therefore, increased amperage is typically required.

Also, since the output voltage from a conventional alternator is volatile (it could reach more than 3 times between maximum and minimum), a conventional alternator together with a rectifier is not a perfect power supply. The varying voltage not only results in fluctuating brightness of the display unit (in the worst case it could shut down the display completely), but it . can also significantly reduces the working life time of the display element

The transportable container will typically be adapted for transporting food, the container in the form of a box, typically for attachment to a rear portion of a motorcycle or motor scooter. In an alternative embodiment, the container may be attached to the roof of an automobile, or carried by a person.

One or more illumination elements are preferably positioned between the exterior walls of the container, and their respective, adjacent interior walls. The illumination elements are typically actuated manually by a switch which can be located on the box, or on the motorcycle, and are powered by the adapted power supply system of the motorcycle.

In an alternative embodiment, the illumination elements are actuated automatically when the motorcycle is turned on or started. The exterior walls are typically transparent, or translucent. Therefore, when the iUumination elements are actuated, the light from the Rumination elements shines through walls. Indicia are preferably displayed on the outside face of the extenor walls, and the light aids in the display of the indicia, typically at night time. The indicia may represent the manufacturer/retailer of the food being delivered, or represent any other business, whether related or not to the food being delivered.

The structure and interior walls of the container are typically mainly constructed from fibre glass, and the exterior walls are typically constructed from polycarbonate. Alternatively, the interior walls of the box and the exterior walls may be mainly constructed from any suitable polymeric materials with ABS for exterior walls and polypropylene for interior walls being particularly preferred materials. The interior walls are typically insulating, to reduce and/or prevent loss of heat generated by the food within the interior portion.

A heat source may be provided in the container, preferably in the form of halogen globes, but any heat source may be used. The heat source is preferably located on the floor of the box and is powered by the electrical supply system of the motorcycle. The heat source is typically actuated manually by a switch which can be located on the box, or on the motorcycle. In an alternative embodiment, the heat source is actuated automatically when the motorcycle is turned on or started. When actuated, the heat source aids in maintaining a warm to hot temperature within the interior portion, to keep the food therein warm.

In an alternative embodiment of the invention, the heat source is replaced with a cooling source, and the box is configured to transport cold items, such as ice cream and refrigerated meats.

. The preferred illuminated elements may consist of neon tubes, LED panel screen or EF (electronic field) panel.

The input electrical energy, may be supplied by an alternator from the motor scooter, rechargeable battery (for scooters run mainly on electrical power rather than combustion) or using an alternative supply such as solar energy from the sun at daytime.

The preferred alternator maintains a higher voltage at increasing amperages than a conventional alternator and also provides a higher amperage at all speeds of engine operation (with a constant voltage output) than a conventional alternator.

The alternator of the present invention will normally produce multiphase alternating current and preferably, three phase current is produced. The number of coils present in the altematoi will normally be increased and the coils will normally be divided into three groups.

In the most preferred configuration, 12 coils are provided on the stator core, the coils divided into three groups of four coils each. '^:

The alternator of the preferred embodiment also preferably includes a larger diameter of wire used to make the coils in order to low copper wire resistance and ininirnize heat creation.

Further, more fixed magnets are preferable provided about the rotor of the alternator. Preferably, 4 pairs of magnet poles will be provided.

It is preferred that the system includes a switch mode power supply and AC/DC converter to convert low DC voltage to high AC voltage and stabilise the power supply to the container and particularly the illuminated display means.

The illuminated display means and/or heat or cold source will typically be capable of functioning even if the battery ceases to provide power.

The rectifier of the system may input power directly to the switch mode power supply. If so, then a transformer will normally be used to convert the DC power to AC power which the illuminated display means and/or heat or cold source can use. This will typically be approximately 2S00V in the case of neon tubes.

Alternatively the alternator may feed the switch mode power supply directly or via the rectifier.

It is preferred that the switch mode power supply will output a consistent DC output of about approximately 12V DC.

A switch mode power supply of the type 384X, normally 3843 is preferred. The preferred SMPS operates at high frequency isolating the input and output by using PWM (pulse width modulation) technology. It allows for a much wider range of changing input voltage (Vi=12V~30V input voltage range) to supply a constant output voltage. UC3843 is the preferred PWM circuit

. The switch mode power supply will normally have an associated adjustable shunt regulator, preferably of the type TL431. Electronic switch-mode DC to DC converters (switch mode power supply) convert one DC voltage level to another, by storing the input energy temporarily and then releasing that energy to the output at a different voltage. The storage may be in either magnetic field storage components (inductors, transformers) or electric field storage components (capacitors). This conversion method is more power efficient (often 75% to 98%) than linear voltage regulation (which dissipates unwanted power as heat). This efficiency is beneficial to increasing the running time of battery operated devices.

As the power from the alternator will normally vary according to the engine output or RPM, the switch mode power supply will act to smooth the delivery of the power to the illuminated display means and/or heat or cold source.

The alternator and switch mode power supply will typically be capable of being retrofit to an existing motor scooter.

In this manner, the existing alternator of the scooter can simply be replaced with an alternator of the new type, and the existing power supply network can then continue to run the existing devices and still charge the battery. A portion of the power produced by the new alternator is also provided to the switch mode power supply which in turn provides this power to the illuminated display means and/or heat or cold source, which has also been retrofitted to the scooter in a stabilised manner. The consistent power supply to the illuminated display means and/or heat or cold source is therefore provided regardless of the number of other loads on the scooter electrical system and also less reliant on the speed of the engine of the scooter to maintain ^' the power. Without the switch mode power supply, operation of the illuminated display means and/or heat or cold source would require that the scooter remain running at all times in order to power the illuminated display means and/or heat or cold source or at least run at much higher RPM.

According to the invention, the new alternator can provide the level of power required and the switch mode power supply will stabilise the provision of power to the illuminated display means and/or heat or cold source without sacrificing the other devices required to operate the scooter.

Another aspect of the invention includes a vehicle in the form of a motorcycle with a container as described above attached to a Tear portion thereof and with an electrical supply system as described above to power the container. Brief Description of the Drawings.

Various embodiments of the invention will be described with reference to the following drawings, in which:

Figure 1 is a schematic illustration of the electrical supply system according to a preferred embodiment of the present invention.

Figure 2 is a schematic representation of the alternator design parameters.

Figure 3 is a circuit diagram for a preferred 12V DC to DC switch power supply using a pulse width modulation circuit and an adjustable shunt regulator.

Figure 4 is a sectional end view of an alternator according to a preferred embodiment of the present invention.

Figure 5 is a sectional side view of the alternator illustrated in Figure 4. Figure 6 is an end view of the outer casing of the alternator illustrated in Figure 4.

Figure 7 is a graph showing alternator output V-I characteristics for an alternator according to an aspect of the present invention compared to- a conventional alternator and an ideal alternator with the same speed of rotation.

Figure 8 is a graph showing alternator output amperage at varying engine speeds, for an alternator according to an aspect of the present invention compared to a conventional alternator and an ideal alternator.

Detailed Description of the Preferred Embodiment. In a preferred form, the present invention resides in an electrical supply system for a mobile vehicle, namely a scooter.

The electrical elements of the illuminated box described here consist of neon tubes and a transformer, which converts low DC voltage 12V into high AC voltage around 2500V. To prevent flashing of neon tubes, we have to stabilize the input voltage of the transformer.

The aims to design a new electrical power system are:

a) Cost effectiveness

Based on current structure measurement and shape of scooter, engine and alternator to develop the new system with cost effectiveness,

b) Extra power To be able supply sufficient electrical power around 35% more than existing power system,

c) Stabilizing the system voltage

To introduce the technology of switch power supply in stabilizing the electrical power system for the illuminated box.

It involves the following parts: alternator, rectifier and power supply for illuminated box.

Analysis facts

a) Max electrical power

The requested electrical power for a scooter with illuminated box is 35 watts more than a single scooter. Electrical power for a single motor scooter can be calculated by lamps (80 watts), speedometer (10 watts) and ignition (20 watts).

The amount of power required by a scooter with illuminated box therefore is (80W+10W+20W) + 35W=145 watts.

The required current I=W/V=145/12==12A. Therefore, more than 35% of extra power is required by an electrical system including an illumination means.

b) Equivalent load R(equivalent)

If all electrical resistant loads can be treated as an equivalent load, we can find out R(equivalent) by using the following formula: R(equivalent)=V/I=12V/12A≈1Ω.

Interior equivalent road R(interior) is formed by wire resistance. The larger the outer diameter of the copper wire, the less resistance experienced.

Design and calculation

(a) Alternator design

Most conventional scooter alternators generate single phase alternative current. Stator coils divided into different groups is a common design for 150cc scooter, one group for lamps, the second group for ignition and the last group for the rest of the electronic devices including the battery charger. This design can keep the cost lower. The maximum output current from a rectifier is around 8A to 10A.

In order to generate the higher current required by the addition of the illuminated display means, three phase alternating current is required in the system of the present invention. The use of three phase power will increase the power, but the rectifier will also required to convert the three phase AC power into DC for the battery and other loads of the scooter, including possibly as an input power source for the SMPS explained below.

For this purpose, 12 coils have been provided, divided into three groups of four coils have been used in the preferred alternator and the diameter of the wire used in the coils has also been increased as use of the conventional diameter wire would create more heat when the output power requested increases. The larger the outer diameter of the copper wire, the less resistance experienced. Therefore temperature increases caused by the resistance will be smaller if larger gauge wire is used.

Without wishing to be limited by theory, from the basic equation of electro tnagnetism,

Ε=ΔΦΝ/ΔΤ (4)

E-> in voltage,

N-> numbers of coil.

ΔΦ-> the total flux of the conductor during time ΔΤ

ΔΦ=ΒΔΑ,

B-> Magnetic field density

From formula 4, we can have:

E=BNliXi> (5)

1-S> coil dimension in depth,

r-> radius between coil frame to its rotating centre point

ω-> coil rotating velocity

According to formulas (4) and (5), a designer can increase output power by changing the following elements.

i. increasing magnet field density B

ii. adding an extra number of coils

iii. extending coil frame dimension of 1 (depth inside of magnet field)

iv. speeding up stator coil (in this case, the rotating part is the fly wheel combined with permanent magnetic cylinder) v. enlarging size of copper wire

Conditions (iii) and (iv) cannot be changed easily as they both involve redesign of the engine providing the output power. Changing condition (i), can increase current but it also contributes more heat as B (magnetic field density) is increased.

However changes to (ii), and (v) would be less complex in the present invention through a redesign of the alternator used.

The design of the present invention is able to supply sufficient current: i. To obtain three phase output, divide twelve stator coils into three groups, each group having four coils.

ii. To enlarge diameter of wire from 0.78~0.85mm to 0.91 mm iii. To arrange four pairs of magnet poles around the fly wheel of alternator.

Rf interiori calculation

According to copper wire gauge 19# data sheet, the resistance of wire R=0.0265Q/m (wire diameter=0.91mm).

The length of each group wire is around 10 meters.

Rl=R2=R3=O.O265xl0=0.265Q

Test report

The alternator of the present invention is able to supply up to 170 watts ^* of output power compared with normal alternator generates 120-125 watts. It gives sufficient power to run the newly added illuminated box as well as the remainder of the normal mechanisms of the motor scooter.

The alternator of one preferred form of the present invention is illustrated in Figures 4 to 6. It can be seen that the alternator of the present invention includes 12 coils S mounted on a stator 3. A flywheel 1 is mounted concentrically outside the stator and is separated from the cover 6 by a silicon steel sheet 4. Also located inside the periphery of the cover 6 is a permanent magnet cylinder 2. The flywheel with the permanent magnet cylinder 2 mounted therewith rotates about the stator 3 and inside a magneto cover 6.

(V) Switch mode power supply fSMPSI using UC3S43

To ensure that the illuminated display means will work well, the DC voltage available at input must be stabilized due to the variability of the power supply being dependent mainly on the speed of the engine of the motor scooter, using a high voltage converter. For customer satisfaction, the illuminated display means should keep working even under the worst case scenario when the battery is broken down.

The preferred SMPS operates at high frequency with isolating input and output by using PWM (pulse width modulation) technology. It allows for a much wider range for the changing input voltage (Vi=12V~30V input voltage range) to supply a constant output voltage. UC3843 is the preferred PWM circuit that works as long as input voltage is over 8.2V. It starts operation when voltage is over 9V.

UC3843 under woltage lockout (UVLO)

An internal undervo tage lockout (UVLO) circuit in the monitors the input voltage and keeps the illumination means in shutdown mode until the input supply rises above the UVLO threshold. If a battery is present when the input power is applied, the input supply must rise to above approximately 7.8V before the illumination means becomes operational. The UVLO circuit places the illumination means in shutdown mode if the input supply falls to approximately 7.0V.

In practice however, the electrical power supply system of the present invention will start the illumination means at a voltage as low as Vi=6V. Even in the worst scenario, the neon tubes will continuously work while battery is broken down, typically using the input power from the alternator or other power source, In fact the illumination means can work well as long as input voltage range between Vi=6~30V .

By combining with preferred alternator, this new power supply system is able to provide increased power, as well as a stable power supply to the illuminated display means whilst maintaining the other systems already present on the motor scooter.

Although the invention has been described with reference to particular examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms. For example, the box 10 may be configured for delivery of any products, such as automotive parts and accessories, computer parts and accessories, stationary, etc. In these cases, the heat source would either be removed, or simply not actuated.

In the present specification and claims (if any), the word "comprising" and its derivatives including "comprises" and "comprise" include each of the stated integers but does not exclude the inclusion of one or more further integers.

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations.

In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (if any) appropriately interpreted by those skilled in the art.

Claims

Claim

1. An electrical supply system for use with a motor scooter having an illuminated display means, the system including an input electrical power supply, a rectifier to convert the- input power to direct current, a battery to store extra power when voltage from the rectifier is in excess of that necessary and to supply voltage when voltage is required, a switch mode power supply and AC/DC converter to convert low DC voltage to high AC voltage and stabilise the power supply to the illuminated display means.