GB2339092A

GB2339092A - Mobile phone battery pack chargeable from AC mains supply

Info

Publication number: GB2339092A
Application number: GB9814265A
Authority: GB
Inventors: Hung-Ming Shih
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-06-26
Filing date: 1998-07-01
Publication date: 2000-01-12
Also published as: NZ330831A; GB9814265D0; BE1012166A6; AU729794B2; FR2783108B3; NO983173L; FR2783108A1; CA2242664A1; DE29812606U1; NL1010026C2; AU7322298A

Description

2339092 Title: AC/DC Rechargeable Mobi.le Phone Cell The present invention

relates to AC/DC rechargeable mobile phone cells, especially a mobile phone cell which can be charged directly by mains power or charged by an ordinary DC charger available on the market.

To charge a traditional mobile phone cell for replenishing the consumed energy, a charger must be used. For this reason, the user has to buy an extra charger and pay more money. Furthermore, the charger is too large and too heavy and cumbersome to carry.

Because of these disadvantages, improvements have been made. As shown in Fig.

I of the accompanying drawings, the rechargeable cell is composed of a case 10 and a charger. A concave cabinet 13 with two notches on its left and right is placed on the panel 12 of the case 10 to hold a plug 15. The plug 15 has two forward extending electric insertion pieces 16 and a conducting support axle 17 transversely connecting the electric insertion pieces 16. Left and right conducting plates 18 with notches are installed on the circuit board I I of the charger to grip the conducting support axle 17 of the plug 15. Mains power AC can be supplied into the charger through the electric insertion pieces 16, conducting support axle 17 and conducting plate 18 of the plug 15. However this design of the conducting support axle 17 increases current resistance; in addition, the contact between the conducting support axle 17 and the conducting plates 18 of the circuit board 11 is not firm. Furthermore, when the plug 15 is everted or retracted the conducting support axle 17 is not detached from the conducting plate 18 so that there is abrasion which results in lower conductivity. Because the positioning of the conducting support axle 17 of the plug 15 is based on the firm assembly of the circuit board I I and the supporting of the conducting plate 18, loosening can occur. This is not an ideal structure for operation.

- Another shortcoming is that plug 15 is the AC input te rniinal of the charger. After' rectifying, filtering and stabilizing, the AC is converted into DC to drive the 2 transformer and charging circuit through a driving circuit composed of transistors.

The DC, on the one hand, is used to charge the rechargeable cell 19, on the other hand, supplies energy to the mobile phone through the DC output terminals of the panel 12. When the cells 19 are fully charged, the charger cannot shut down the driven circuit automatically. It will result in energy wasting and life- time shortening of the circuit and cells 19. Another problem is that there is no indicator for full charging and no overheating protection for the cells 19.

The present invention may provide an AC/DC rechargeable mobile phone cell io with a plug having a plastics axle held between a concave cabinet of a front panel and a back case body, electric insertion pieces of the plug pressing on flexible conducting pieces of a charger circuit board. When the plug is retracted and housed, the electric insertion pieces will be detached from the flexible conducting pieces. It can be fast and firmly assembled as a whole. It is durable and its conducting quality is improved.

The eversible and locatable plug may be placed on the back of the case body so that the rechargeable cell can be directly charged by mains power without detaching it from the mobile phone.

A dual-colour LED, a thermal sensitive resistor and rechargeable cells may be connected in parallel across the charging circuit. When the charging voltage is lower than the reference voltage, the red light of the dual LED is lit up. When the cells are fully charged, the green light of the dual LED is lit up and a low potential is output to an optic-coupling switch from a linear IC to stop recharging. Accordingly energy is saved and the cell's life is prolonged.

Constructional embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, wherein:Fig. I shows an exploded view of a known rechargeable mobile phone cell; 3 Fig. 2 shows a rear view of a cell according to the present invention; Fig. 3 shows an exploded view of the cell shown in Fig. 2; Fig. 4 shows a rear view of the cell according to Fig. 2 in an alternative position; Fig. 5 is a partial sectional plan view of Fig. 4; Fig. 6 is a partial sectional side elevation of Fig. 4; Fig. 7 is a partial sectional side elevation of Fig. 2; Fig. 8 is a block diagram of the cell according to the present invention; Fig. 9 is a circuit diagram of the cell according to the invention; and Fig. 10 is a front view of a cell according to a second embodiment of the present invention.

The AC/DC rechargeable mobile phone cell is a rechargeable mobile phone cell which can be directly charged by mains power; usually AC 110-240V. As shown in Fig. 2 a charger is fixed in a case and a concave cabinet 22 space is formed on the front of a panel 20 of the case to hold a plug 30 which can be everted and located as well as retracted and housed and which is used for directly charging with the mains power.

As indicated in Fig. 3, the case of the rechargeable cell is composed of the panel 20 and back case body 21 connected together by high-frequency fusion jointing. A concave cabinet 22 space is formed in the front of the panel 20. Notches 25 are made respectively at the rear ends of the left and right side walls 23, 24 of the concave cabinet 22 to fit the left and right sections of the plastics support axle 32, 33 of the plastics body 31 of the plug 30. The left and right electric insertion 4 pieces 34, 35 of the plug run through the plastics body 31 and are longer in front and shorter in the rear. A pair of plastics supporting plates 26, 27 are placed on the inner side of the back case body opposite each other with one on the left, the other on the right. The plastics supporting plates grip the supporting axle 32, 33 of the plug with their notches 28 located at the front end of the plates to enable the plug 30 to be everted or retracted around the axle.

The charger circuit board 50 and rechargeable battery cells 67 are firmly installed in the case of the rechargeable cell. Two flexible conducting pieces 51, 52 stretch out of the circuit board 50 and are used as AC input terminals. The rear ends of the electric insertion pieces 34, 35 of the plug 30 are resiliently pressed on the pieces 51, 52. Figs. 4, 5, 6 show the plug 30 in everted and located position. The plastics body 31 of the plug 30 matches the left and right walls 23, 24 of the concave cabinet 22. The plastics supporting axle 32, 33 is gripped and held by a supporting plate 26, 27 and its notches 25, 28 of the same material. This method can reduce electrical resistance and improve current conducting quality so that the AC current can run into the charger through the electric insertion pieces 34, 35 of the plug 30 and flexible conducting pieces 51, 52 smoothly. In addition, it is durable and can be assembled fast and firmly.

As indicated in Fig. 7, when the rechargeable cell does not need charging the plug may be retracted and housed in the concave cabinet 22 space of the panel 20 and the rear ends of the electric insertion pieces 34, 35 of the plug 30 will be detached from theflexible conducting pieces 51, 52 of the circuit board 50.

As indicated in Fig. 8, AC I 10-240V power enters the AC input terminals 60 of the rechargeable cell, and then goes through the rectifying circuit 61, filtering circuit 62, voltage stabilizing circuit 63, driving circuit 64 and charging circuit 65 to charge the rechargeable cells 67. When using mains charger, the charging current runs through the DC terminal 69 and flexible charging piece 42 (as indicated in Fig. 3) into rechargeable cells 67. When the rechargeable cells are My charged, the DC can be connected into the mobile phone through DC output terminal 68 and flexible supplying conducting pieces 41., 42.

With reference to Fig. 9, the AC I 10-240V power enters the AC input terminal 60 of the charger and is then rectified into DC current through a bridge connected rectifier D I of the rectifying circuit 6 1. The current limiting resistor RI is used to limit the current within a definitive range; the resistor R2 and diode D2 combined with the transistor Q1 are used as a filter, and together with a Zener diode D3 in the voltage stabilizing circuit provide a comparing reference voltage for the over current protection section in the driving circuit.

A switching circuit, which provides a proper voltage to control the transistor Q2, is composed of a transistor Q1 and an optical coupler El. The rechargeable cells 67 are charged through a transformer and charging circuit 65. The charging circuit 65 is connected to the output terminal of the transformer's secondary coil.

The following elements are connected in the charging circuit 65 in parallel: a dual colour LED, a capacitor E4 serially connected with a diode D4, and the rechargeable cells 67. Through a Zener diode D5 and resistor R7, a linear IC E2 is connected at the connecting point of the capacitor C4 and diode D4 to provide a reference voltage. Another end of the linear IC E2 is connected to the cross-over point of the dual colour LED to compare the charging voltage with the reference voltage. While the voltage is lower than the reference voltage (the potential of pin No. 3 lower than that of pin No. 2), the driving circuit 64 is driven to work, and the rechargeable cells 67 are charged through the transformer and the charging circuit 65. At the same time, the dual colour LED (refer to the light window 29 in Fig. 3) is lit up with red colour showing it is charging. When the rechargeable cells are full charged (the potential of pin No. 2 lower than that of pin No. 3), the diode D4 is conducted and the dual LED is lit up with green colour. At the same time, a lower potential is output to the optical switch IC E I from the linear IC E2 to cut-off the transistor Q2 and stop charging. As a result, the energy is saved and the life of the circuit and cells is prolonged.

6 Before the rechargeable cells 67 are connected to the output terminals of the secondary side of the transformer, two thermal sensitive resistors RIO, RI I of an over-heating protection circuit 66 are serially connected with it. While the temperature inside the rechargeable cell 67 is rising, the resistance of the thermal sensitive resistors RIO, RI I is going down correspondingly, which provides an over-heating protection to stop charging the rechargeable cells.

As indicated in Fig. 10, the concave cabinet 220 is placed on the back of the case 210 to hold the plug 30 enabling the rechargeable cell to be charged by mains power without detaching it from the mobile phone.

In summary, the AC/DC rechargeable mobile phone cell is durable and can be assembled fast an d firmly; its conductivity is higher than known ones; it is suitable for charging a standby mobile phone; it has indicators for displaying the charging conditions (charging or fully charged); it can stop charging automatically, as a result, the lifetime of the circuits and rechargeable cells are prolonged. It can meet all practical requirements.

7

Claims

An AC/DC rechargeable mobile phone cell comprising a case having a panel and a back case body, a concave cabinet being arranged on the front of the panel to hold a plug, the cell further comprising a charger installed in a case in which charger alternating current is input through an AC input plug, and then rectified, filtered and stabilized to drive a transformer and a charging circuit through a transistor driving circuit to charge the rechargeable cells with DC, its DC output terminal being connected to flexible conducting pieces for supplying DC to the mobile phone, wherein a plastics supporting axle extends at its two ends on the left and right side of a plastics body of the plug to fit into left and right notches of the concave cabinet, the ends being gripped by front notches of left and right supporting plates which are installed in the back case facing the notches of the concave cabinet, left and right electric insertion pieces of the plug extending through the plastics body of the plug, two resilient conducting pieces, used as AC input terminals, extend out of the circuit board and press on the rear ends of the electric insertion pieces of the plug when the plug is everted, an optical coupling switch is connected to the base of the transistor of the charger's driving circuit; the charging circuit is connected to the output terminal of the transformer's secondary coil, the following elements are connected across the charging circuit; a dual colour LED, a capacitor serially connected with a diode, and the rechargeable cells, a linear IC is connected at the connecting point of the capacitor and the diode through a Zener diode to provide a reference voltage, another end of the linear IC is connected to the cross-over point of the dual colour LED to compare the charging voltage with the reference voltage, while the voltage is lower than the reference voltage, the dual colour LED is lit up with red colour, when the rechargeable cells are fully charged, the diode is conducted and the dual LED is lit up with green colour, at the same time, a lower potential is output to the optical switch from the linear IC to cut-off the transistor in the driving circuit.
2. An AC/DC rechargeable mobile phone as claimed in claim 1, wherein the plug on its case can be retracted and housed into the concave cabinet of the panel, and at the same time, the electric insertion pieces of the plug are detached from the flexible conducting pieces of the circuit board with their rear ends upward.
3. An AC/DC rechargeable mobile phone cell as claimed in claim I or 2, wherein the concave cabinet is placed in the back of the case to hold the plug so that the mobile phone can be charged with mains power without detaching.
4. An AC/DC rechargeable mobile phone cell as claimed in any one of claims I to 3, wherein rechargeable cells are serially connected with a thermal sensitive resistor before connecting to the secondary coil of the charger.
5. An AC/DC rechargeable mobile phone cell, comprising a housing containing a charging circuit including flexible contacts, the housing including plastics mountings and a recess for a plug which is pivotably mounted in the mountings and has pins for insertion into a mains socket, the plug being pivotable from a retracted position in which it is housed within the housing to an everted position in which it is located with one end of the pins extending from the housing and the other end of the pins engaging the flexible contacts of the charging circuit.
6. An AC/DC rechargeable mobile phone cell substantially as described herein with reference to either of the embodiments shown in Figs. 2-10 of the accompanying drawings.