GB2470968A

GB2470968A - Power supply protective terminal

Info

Publication number: GB2470968A
Application number: GB0916317A
Authority: GB
Inventors: Kuan Chun Wang
Original assignee: Kerio Technologies Inc Taiwan
Current assignee: Kerio Technologies Inc Taiwan
Priority date: 2009-06-09
Filing date: 2009-09-17
Publication date: 2010-12-15
Also published as: GB0916317D0; TW201044157A

Abstract

A terminal device for is connected between a power supplying apparatus and an electronic product and has a wire set 21, a non-active component 231 having a conductivity voltage threshold and a switch unit 25 that is activated to permit the output voltage to pass when the threshold is exceeded. Non-active component 231 may have a load resistor 233 and be a zener diode a forward biased diode, or plural light emitting diodes in series. The switch may be a relay (fig 5, 253) or an integrated circuit and be operated by a transistor 255 or a field effect transistor. A feedback signal (fig 9, 215) may command the power supply to maintain or change its output voltage using a voltage selection unit (fig 8, 307) that sequentially changes the voltage until the ideal voltage is reached. By monitoring the voltage output by the power supplying apparatus the device ensures that the power is output at a level required by an electronic appliance such as a laptop computer.

Description

TERMINAL DEVICE PROVIDED WITH NON-ACTIVE COMPONENT

THAT HAS THRESHOLD FOR ELECTRICAL CONDUCTIVITY AND

POWER SUPPLYING APPARATUS PROVIDED WITH THE SAME

FIELD OF THE INVENTION

The present invention relates to a terminal device for being used in a power supplying apparatus, and more particularly, to a terminal device provided with a non-active component that has a threshold for electrical conductivity, as well as the power supplying apparatus provided with the same.

DESCRIPTION OF THE RELATED ART

Nowadays, the circuit elements present in the major electronic devices pertain to the digitized circuit elements that are designed to consume low voltage DC electricity. However, the electric power supplied by a power plant is normally in the form of alternating current with a much higher voltage. As such, voltage conversion must be carried out before the electric power is supplied to the electronic appliances from a wall socket.

A power supply 12 with adjustable output voltage as shown in Figure 1 is now available in the market and serves to provide different voltages required by various electronic products. The conventional power supply 1 is configured to adjust the output voltage by providing a slide switch 14 connected to the output wire and adapted for adjusting the resistance of a variable resistor mounted therein, thereby operatively changing the voltage level of the electric power that is to be output via the output terminal 13.

Such an apparatus may significantly reduce the number of power converters that a consumer should have at home. However, problems may come along over time as the actuator 15 of the switch 14 will get loose gradually after a long time use, resulting in an increased probability of unstable output voltage. Especially, the output voltage can be still altered by switching the switch 14 during the power supplying operation of the power supply 12.

Once false touch causes the power supply to be switched, it is possible to result in the risk of hazard and damaging an electrical product.

On the other hand, in considering the cost effectiveness and portability, manufacturers of portable electronic products normally build safety circuits in the converters that are exclusively useful for their own products, while asking consumers not to use converters of other types. Generally, the laptop computers available in the market are manufactured to tolerate a 5% plus/minus variation in the ideal voltage level. In other words, damage would occur to the intrinsic circuits of the laptop computers if the incoming voltage goes beyond the predicted range.

In the case where the original parts are either missing or not on hand, a consumer may have to acquire a non-original converter from the market. It would be quite burdensome for the amateur consumers. In addition, the commercially available voltage converters, which are manufactured with reduced cost, may not have a circuit design for monitoring the output voltage and enabling an alarm in response to detection of the occurrence of an output fault. Even if the non-original converter is equipped with a monitoring device, the consumer may still have to face a risk of abrupt output voltage fluctuation due to inferior quality control.

Great British Patent Application No. 812149.3 assigned to the present applicant has proposed a miniature terminal device 2 for coupling to a charging port of a mobile phone 91 to serve as a safety device, as shown in Figure 2. The electricity consuming device is charged by mating the terminal device 2 to an output port of a power converter 3, such that a converter body 30 takes AC power from a wall socket 8 via a plug 32 and converts it into an output voltage which is subsequently monitored by the terminal device 2. The terminal device 2 blocks the non-ideal over-and under-voltages and allows only the ideal DC voltage to flow into the mobile phone 91.

However, the terminal device disclosed in the above patent application mainly utilizes an active component to be a controller device. Therefore, the terminal device will continuously consume energy, regardless of whether a power charging operation is carried out or not. It does not match the trend towards environment friendly products on one hand and may cause additional problems due to continuous generation of heat on the other hand.

Therefore, there exists a need for a miniature safety fitting that is cost-effective as compared to the portable electronic appliances to which it may be connected and is capable of ensuring that the power output from any type of power converters is at a stable and safe level demanded by the specifications of the electronic appliances to which it may be connected.

Preferably, the safety fitting does not consume energy until a power charging operation is carried out and, more preferably, the converter body is capable of automatically adjusting the level of output voltage until a correct voltage is reached. The present invention provides the best solution in response to the need.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide a terminal device for use in a power supplying apparatus, which is extremely safe as it will decline to transmit electric power at an undesired voltage level.

Another object of the invention is to provide a terminal device for use in a power supplying apparatus, whose structure is so simple and compact as not to adversely affect the portability of the electronic appliances to which it is connected.

It is still another object of the invention to provide a terminal device for use in a power supplying apparatus, whose monitoring circuit is made up of a non-active component to achieve the energy-saving purpose and catch up with the trend towards environment friendly products.

It is still another object of the invention to provide a terminal device for use in a power supplying apparatus, which is capable of continuously monitoring the voltage/current output from the power supplying apparatus and cutting off the power supply to an electronic appliance in response to detection of the occurrence of an output fault, thereby ensuring that damage will not occur to the electronic device as a result of the output fault.

It is still another object of the invention to provide a power supplying apparatus having a terminal device connected thereto, which is extremely safe as it will prevent damage to the electronic appliances to which it is connected.

It is yet another object of the invention to provide a power supplying apparatus which, when a voltage output from the converter body thereof is not permitted to pass through the terminal device, automatically adjusts the level of output voltage until the output voltage reaches a level required by the terminal device, thereby providing great convenience and safety for users.

The present invention therefore provides a terminal device for being used in a power supplying apparatus, where the terminal device is provided with a non-active component that has a threshold for electrical conductivity. The power supplying apparatus comprises a converter body for outputting an output voltage. The terminal device is adapted for being electrically connected to an electricity consuming device that is to be powered by the power converter. The terminal device comprises: a wire set for receiving the output voltage, including a high level wire and a low level wire; a non-active component having a predetermined voltage threshold for electrical conductivity; and a switch unit adapted for being activated by the non-active component in the case where the output voltage substantially reaches the predetermined voltage threshold, such that the output voltage is permitted to pass from the wire set to the electricity consuming device.

The present invention further provides a power supplying apparatus for powering an electricity consuming device, the power supplying apparatus being provided with a terminal device. The power supplying apparatus comprises: a converter body including an output port for outputting an output voltage and a terminal device for coupling to the electrically consuming device. The terminal device includes a wire set for receiving the output voltage, including a high level wire and a low level wire; a non-active component having a predetermined voltage threshold for electrical conductivity; and a switch unit adapted for being activated by the non-active component in the case where the output voltage substantially reaches the predetermined voltage threshold, such that the output voltage is permitted to pass from the wire set to the electricity consuming device.

In conclusion, the invention disclosed herein allows users to readily choose an appropriate terminal device as a safety fitting that is well-compatible with the electronic appliance to which it is to be connected, by reference to the voltage and current specifications of the electronic appliance provided by the manufacturer, and connect the same to either a charging port of the electronic appliance or an output port of a power supplying apparatus (such as a power converter or a battery). If the output voltage from the power supplying apparatus is at an undesired level, the terminal device will decline to transmit electric power to the electronic appliance, so that a good quality of power supply can be obtained. In particular, the invented terminal device catches up with the energy-saving trend by adopting a non-active component which does not consume energy in its non-conductive state.

Especially, the terminal device according to the invention is simple in circuit structure and presents advantages of low manufacture cost and compact size, so that the portability of the electronic appliance coupled with the terminal device is not adversely affected. The invention enables users to acquire appropriate terminal devices for the precious electronic appliances of their own and utilize the same in conjunction with any types of power supplying apparatuses available in the market without worrying about any damage that may otherwise occur to their electronic appliances.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and effects of the invention will become apparent with reference to the following description of the preferred embodiments taken in conjunction with the accompanying drawings, in which: Figure 1 is schematic perspective view of a conventional power supply with adjustable output voltage, in which an actuator for adjusting the output voltage is exposed; Figure 2 is a schematic working diagram of a conventional terminal device, in which the terminal device is coupled to an electronic device for power charging; Figure 3 is a circuit diagram for the first embodiment of the invention; Figure 4 is a circuit diagram for a terminal device according to the second embodiment of the invention; Figure 5 is a circuit diagram for a terminal device according to the third embodiment of the invention; Figure 6 is a circuit diagram for a terminal device according to the fourth embodiment of the invention; Figure 7 is a circuit diagram for a terminal device according to the fifth embodiment of the invention; Figure 8 is a circuit diagram for an electricity consuming device and a power converter according to the sixth embodiment of the invention; Figure 9 is a block diagram illustrating the sixth embodiment of the invention; Figure 10 is a schematic working diagram for the seventh embodiment of the invention; and Figure 11 is a schematic diagram for the eighth embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

For illustrative purpose, a general power converter 3 shown in Figure 2 is taken as an example of a power supplying apparatus described in the following embodiments, whereas the mobile phone 91 shown in Figure 2 being exemplified as an electricity consuming device. It will be readily apparent to those skilled in the art that the power converter 3 may be replaced with an external rechargeable battery, and that the electricity consuming device may also be a laptop computer, a personal digital assistance (PDA) or like devices.

As shown in Figure 3, a terminal device 2 according to this embodiment has -10 -a wire set 21, a non-active component 23 and a switch unit 25. The wire set 21 includes at least one high level wire 211 for receiving an incoming power and a low level wire 213 connected to the ground. The non-active component 23 includes a capacitor, a Zener diode 231 and a resistor that serves as a load device 233. In this embodiment, the switch unit 25 includes an integrated circuit device 251 which is activated by the non-active component 23 when receiving an incoming voltage within a predetermined voltage range (such as 16.5 volt), to thereby permit electric power to pass from the wire set 21 to the electricity consuming device via wires 271 and 273. The switch unit 25 further includes a NPN-type transistor 255 whose base terminal 2550 is electrically connected to a point between the Zener diode 231 and the load device 233.

When the electric power is transmitted from a voltage-transforming unit (not shown) to the terminal device 2 through the wire set 21, the high frequency components of the incoming power are grounded through a capacitor coupled between the high level wire 211 and the low level wire 213. The remaining DC components are transmitted into the non-active component 23. According to this embodiment, a Zener diode 231 having a breakdown voltage of 16.5 volt, for example, is employed and reversely positioned in such a manner that it is electrically connected at its output terminal to the high level wire 211 and electrically connected at its input terminal to the low level wire 213.

-11 -Therefore, when the incoming voltage Vcc from the high level wire 211 is lower than the predetermined level of 16.5 volt, the electrical current is blocked by the Zener diode 231 and directly connected to the ground through the low level wire 213, such that the input terminal of the Zener diode 231 connected to the low level wire 213, the load device 233 and the base terminal 2550 of the transistor 255 have the same potential equal to the ground voltage. This causes an open circuit between the collector and emitter terminals of the transistor 255, which in turn renders the base voltage of a downstream transistor 257 to be Vcc. The closed circuit condition between the collector and emitter terminals of the transistor 257 results in a reduced voltage level at the collector terminal 2571 and, therefore, a low level signal is transmitted into the fourth pin of the IC device 251. As a consequence, the IC device 251 blocks the current flow from the high level wire 211 to the wire 271.

If the incoming voltage is larger than 16.5 volt, the reversely positioned Zener diode 231 breaks down to create a closed circuit. At this time, the voltage at the base 2550 of the transistor 255 reaches a high level, resulting in a closed circuit between the collector and emitter terminals of the transistor 255 and making the collector terminal electrically connected to the ground. The low collector voltage of the transistor 255 causes the base voltage of the transistor 257 to drop down to the low level, which in turn places the collector terminal 2571 and the emitter in a disconnected state.

The voltage at the collector 2571 approaches Vcc accordingly and, -12 -therefore, a high level signal is transmitted into the fourth pin of the IC device 251. As a consequence, the switch unit is in a closed circuit condition at which the current is allowed to flow from the high level wire 211 to the electricity consuming device (not shown) through the wire 271.

By virtue of the control mechanism described above, an under-voltage below a predetermined level is prevented from being input to the electricity consuming device. Especially, the non-active component 23 does not consume electricity at its non-conductive state and matches the trend towards environment friendly products.

On the contrary, in order to protect an electricity consuming device from over-voltage damage, the IC device 251 described above may be replaced with an IC switch which is designed to become conductive in response to a low level signal input into the fourth pin thereof and break the circuit upon receiving a high level signal. Definitely, it will be readily apparent to those skilled in the art that to obtain a DC output voltage of 19 volt, for example, one may couple a first circuit, which is arranged to become conductive when receiving a voltage of no more than 19.5 volt, in series to a second circuit, which is made conductive in response to an incoming voltage of no less than 18.5 volt. The upper and lower voltage threshold limits will ensure that the voltage to be introduced into an electricity consuming device is at a precise level.

Of course, the non-active component can also be fabricated by either -13 -replacing the NPN-type transistors 255 and 257 with field-effect transistors 255'and 257' as illustrated in Figure 4, or substituting the IC device 251 with a relay 253 as illustrated in Figure 5, without compromising the effects thereof. In addition, the circuit design described above, which is arranged to become conductive by receiving an incoming voltage below a predetermined safety threshold, can be modified as shown in Figure 6, where when the Zener diode 231 breaks down in response to an overly high level of Vcc, the high voltage at the base 2550 of the transistor 255 leads to a closed circuit between the collector and emitter terminals of the transistor 255. The voltage at the pin of the relay 253 connected to the collector terminal of the transistor 255 is at a low level accordingly, causing a coil within the relay 253 to generate a magnetic field. As a result, the high level wire 211 is disconnected from the wire 271, such that the current flow is blocked and the over-voltage is prevented from passing through.

It should be noted that the non-active component used herein is not limited to include a Zener diode. A light emitting diode will not permit a current flowing therethrough if the voltage difference between the two terminals thereof does not reach a predetermined threshold (such as 2.4 V). In this case, a slight current starts to flow across the light emitting diode once the voltage difference between its two terminals goes above 2.4 V. Therefore, according to the fifth embodiment of the invention shown in Figure 7, three light emitting diodes 231" connected in the forward direction to a high level wire 211" and a low level wire 213" are provided to replace the Zener diode -14 -used in the embodiments above. When a voltage of 9 volt, for example, is transmitted through the high level wire 211" of the wire set 21", a current flows across a load device 233", so that the voltage at a base 2550" of a transistor 255" is at a high level to enable an electrical connection between the collector and emitter terminals of the transistor 255". As a result, the voltage at the fourth pin of the IC device 251" in the switch unit 25" is at the low level, and the switch is turned off.

On the contrary, there is no current flowing through the light emitting diodes 231" when Vcc is lower than, for example, 7.2 volt. In this case, the voltage at the base 2550" is at a low level, causing an open circuit between the collector and emitter terminals. The collector voltage is consequently made to approach the Vcc, such that the voltage at the fourth pin of the IC device 251" is at a high level, allowing the transmission of electric power from the high level wire 211" to the wire 271". The non-active component according to the invention does not consume energy in its non-conductive state, while using only a slight amount of electricity in its conductive state. Therefore, the invented terminal device does not only achieve the energy-saving purpose and meet the trend towards environment friendly products, but also extends the duration time of the power supplying apparatus, especially in the case where a rechargeable battery is used as the power supplying apparatus.

As shown in Figure 8, for users' convenience, the converter body 30 is -15 -configured to include an input port 301, a voltage-transforming unit 302, an output port 303, a controller unit 304, a signal feedback end 305, a clock generator 306 and a selecting control unit 307. The voltage-transforming unit 302 receives an incoming voltage fed to the input port 301 and converts it into an outgoing voltage which is to be output to the invented terminal device via the output port 303. Referring together to Figure 9, the wire set 21 of the terminal device according to this embodiment includes, in addition to the high level wire 211 and low level wire 213 described above, a feedback wire 215. In the case where the electricity consuming device 9 is designed to use a voltage of 19 V and the selecting control unit 307 is provided with a plurality of resistors having different resistance values, the level of the voltage to be output through the output port can be changed by switchingly connecting different resistors to one side of the inverting input end of the amplifier in the voltage-transforming unit 302 to thereby alter the resistance ratio of the resistors connected at the two sides of the inverting input end.

The level of the output voltage from the voltage-transforming unit 302 may start with a predetermined minimum value (such as 12 V). After a cooperative work of the non-active component 23 and the switch unit 25 in the terminal device, the current is blocked from flowing to the electricity consuming device 9. As a result, a sensor 27 located downstream to the switch unit 25 is unable to transmit any signal to a feedback end 305 through the feedback wire 215. After a period of 3 seconds, for example, -16 -the controller unit 304 switches the circuit of the selecting control unit 307 from one loop to another based on the calculated result by the clock generator 306, thereby altering the resistance ratio of the resistors at the two sides of the non-inverting input end of the amplifier and increasing the level of the output voltage up to the next predetermined value of 15 V. Definitely, it will be readily apparent to those skilled in the art that the feedback operation mentioned above can also be worked out by using either of the high level wire 211 and low level wire 213, instead of the feedback wire 215, to transmit back a signal which is electrically independent from the output power.

Since the output voltage of 15 V likewise fails to reach the threshold value set in the non-active component 23 of the terminal device, the terminal device still blocks the current from flowing to the electricity consuming device 9. After a further period of 3 seconds, the controller unit 304 of the converter body 3 once again switches the circuit of the selecting control unit 307, such that the output voltage is elevated up to, for example, 19 V. At this time, the terminal device permits the current to be output to the electricity consuming device 9, and the sensor 27 transmits a signal indicative of correct output back to the feedback end 305 through the feedback wire 215. The controller unit 304 is consequently commanded to terminate the sequential change in the circuit of the selecting control unit 307, thereby keeping the output voltage at the ideal level.

-17 -The invention enables a user to ensure that a correct voltage is supplied to an electricity consuming device in use by simply coupling an appropriate terminal device to a charging port of the electricity consuming device. If the output voltage deviates from a predetermined range, the invented converter body will automatically adjust the voltage level until a correct voltage is reached. The invention therefore provides great convenience and safety for users.

Of course, the terminal device is not limited to be mounted adjacent to the electricity consuming device. The terminal device may be alternatively coupled to the converter body side. In addition, the electricity consuming device may by way of example be a computer 92 as shown in Figure 10, and the converter body may be a rechargeable battery 301' shown in Figure 11.

The particular internal circuit structure of the converter body and the feedback circuit design of the terminal device as described in the embodiments above are only provided for illustrative purpose. The invention also contemplates other means for changing output voltage, such as a PWM (Pulse Width Modulation) control scheme or like mechanism, so long as the means enables the terminal device to feedback control the converter body and allows the converter body to perform a sequentially switchable output voltage selection to reach an ideal voltage level. The invention therefore leads to a reduced risk of faulty voltage output, an elevated degree of safety for using electronic appliances and prolonged life spans of the electronic appliances, as well as being user friendly and -18 -foolproof to operate.

While the invention has been described with reference to the preferred embodiments above, it should be recognized that the preferred embodiments are given for the purpose of illustration only and are not intended to limit the scope of the present invention and that various modifications and changes, which will be apparent to those skilled in the relevant art, may be made without departing from the spirit and scope of the invention.

Claims

-19 -WHAT IS CLAIMED IS: 1. A terminal device for being used in a power supplying apparatus, where the terminal device is provided with a non-active component that has a threshold for electrical conductivity, and where the power supplying apparatus comprises a converter body for outputting an output voltage, and where the terminal device is adapted for being electrically connected to an electricity consuming device that is to be powered by the power converter, the terminal device comprising: a wire set for receiving the output voltage, including a high level wire and a low level wire; a non-active component having a predetermined voltage threshold for electrical conductivity; and a switch unit adapted for being activated by the non-active component in the case where the output voltage substantially reaches the predetermined voltage threshold, such that the output voltage is permitted to pass from the wire set to the electricity consuming device.
2. The terminal device according to claim 1, wherein the non-active component comprises at least one diode.
3. The terminal device according to claim 2, wherein the at least one diode is a reversely positioned Zener diode comprising an input terminal electrically connected to the low level wire and an output terminal electrically connected to the high level wire, and wherein the non-active -20 -component further comprises a load device connected in series to the Zener diode and positioned between the high level wire and the low level wire.
4. The terminal device according to claim 2, wherein the at least one diode in the non-active component comprises at least one forwardly positioned diode comprising an input terminal electrically connected to the high level wire and an output terminal electrically connected to the low level wire, and wherein the non-active component further comprises a load device connected in series to the diode and positioned between the high level wire and the low level wire.
5. The terminal device according to claim 4, wherein the at least one diode comprises a plurality of light emitting diodes connected in series to each other.
6. The terminal device according to any of claims 3-5, further comprising at least one transistor electrically connected at its base terminal to a point between the diode and the load device.
7. The terminal device according to claim 1, wherein the switch unit comprises an integrated circuit device.
8. The terminal device according to claim 1, wherein the switch unit comprises a relay. -21 -
9. The terminal device according to claim 1, wherein the switch unit, when activated by the non-active component, transmits a first feedback signal to the converter body such that the converter body is commanded to maintain the level of the output voltage, and wherein the switch unit, when not activated by the non-active component, transmits a second feedback signal distinct from the first feedback signal to the converter body such that the converter body is commanded to change the level of the output voltage.
10. A power supplying apparatus for powering an electricity consuming device, the power supplying apparatus being provided with a terminal device, the power supplying apparatus comprising: a converter body including an output port for outputting an output voltage; a terminal device for coupling to the electrically consuming device, including: a wire set for receiving the output voltage, including a high level wire and a low level wire; a non-active component having a predetermined voltage threshold for electrical conductivity; and a switch unit adapted for being activated by the non-active component in the case where the output voltage substantially reaches the predetermined voltage threshold, such that the output voltage is permitted to pass from the wire set to the electricity consuming device.

-22 -
11. The power supplying apparatus according to claim 10, wherein the converter body is a power converter.
12. The power supplying apparatus according to claim 11, wherein the converter body comprises: a voltage-transforming unit; and a selecting control unit electrically connected to the voltage-transforming unit and the wire set and having a clock generator for generating a clock signal such that, upon being driven by the clock generator, the selecting control unit sequentially changes the level of the electrical signals transmitted to the voltage-transforming unit until the wire set transmits back a conduction signal.
13. The power supplying apparatus according to claim 10, wherein the converter body comprises at least one battery.