CN1858545B

CN1858545B - Hand held terminal

Info

Publication number: CN1858545B
Application number: CN200510035902XA
Authority: CN
Inventors: 殷俊杰
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2005-07-10
Filing date: 2005-07-10
Publication date: 2011-06-01
Anticipated expiration: 2025-07-10
Also published as: CN1858545A

Abstract

The invention relates to a mobile communication terminal, and discloses a hand-held terminal, so that the user of the mobile communication terminal can basically defend the injurer, gain valuable escape time, and at the same time ensure the safety of the injurer. In the present invention, a DC-to-AC inverter is added to the hand-held terminal used for mobile communication, and the DC power of the battery in the hand-held terminal is converted into higher-voltage AC power, which is discharged through two electrodes protruding from the shell; the AC voltage It can be around 110 volts, the current is between 8 and 20 mA, and the discharge duration is less than 0.1 second. In addition, a controllable resistance device is connected in series between the inverter and the battery or in the AC discharge circuit. After each discharge, the CPU judges whether the measured discharge current is within the specified range. If not, it indicates that the controllable The resistance device changes the resistance value to adjust the current of the next discharge.

Description

Hand-held terminal

Technical Field

The present invention relates to a mobile communication terminal, and more particularly, to a mobile communication terminal having a guard function.

Background

With the development of modern society, the human material civilization degree is continuously improved, particularly, the human material civilization degree is an unprecedented brilliant period of scientific technology since the twentieth century, and the human creates the most huge scientific achievement and material wealth in history. These achievements have profoundly changed the way and quality of production and life for humans. However, from the global perspective, while the human material civilization progresses, the development of the human mental civilization is relatively slow, even two world war happened in less than one hundred years, and nowadays, violence and crime still happen, especially for women and children in a state of weakness in physiological and psychological conditions.

Women account for half of the world population, are important forces for the construction of human material civilization and mental civilization, and the economic and social development under any social form can not leave the role of women; children are more of the future of the world, care and protection of children are nature of human beings, and the invasion of both is a challenge to the whole human world. So "united nations constitution chapter" specifies: regardless of race, gender, language or religion, there is a need to improve and motivate humanitarian and substantially liberal respect to all human beings. Meanwhile, the united nations also have specially held a plurality of first-brain meetings for women and children, 9 months in 1995, the fourth world women's congress held in Beijing, and the purpose and principle of constitution of the united nations are reiterated, so that the problems of poverty, health care, education, violence to women and the like concerned by the developing nations are reflected emphatically; the issue of children held in the headquarters of the united nations of new york in 2002, 05 and 05, is particularly great and reiterates the promise of children in the next decade. Therefore, how to prevent women, children and the like from being invaded by violence and crimes is an important issue facing all the mankind and all the society.

In the past, women and children mostly adopt self-defense defensive operation such as fist, but the operability of the method for the invaded person who is originally weak in all aspects is not large. The progress of scientific and technological culture provides new hope for protecting women and children. Personal alarms, sprayers, and the like are widely used to protect against insults, but these products are far from adequate to protect the invader. In an emergency, if the facing threat can be relieved and avoided by a fastest, rapid and most effective technological means, the physical, mental and property of a plurality of people can be timely and actively saved. Otherwise, even if the criminal can be restrained after the incident, the injury already occurs. Therefore, by means of the latest technology, the invention of a product for preventing the invasion more quickly and effectively has great significance.

The weapon is the most commonly used tool for self-protection, and the application example of the weapon is that the branch stick is adopted to resist the invasion of the wild beast by the most ancient human ancestors, and when the individual suffers from external threat nowadays, the weapon protects oneself with firearms, cutters and the like.

However, firearms, knives, etc. are dangerous weapons themselves, and are widely used by non-professionals such as women and children, which easily causes irrecoverable accidents; the weapon is inconvenient to carry and high in professional requirement, so that the weapon carried by women and children when going out obviously does not conform to the living habits of people; such weapons are themselves very aggressive and the flooding of firearms and the like may further exacerbate social turbulence and peace confusion problems.

Disclosure of Invention

In view of the above, the present invention is directed to a handheld terminal, so that a user of a mobile communication terminal can perform basic defense for an injury implementing person, thereby gaining valuable escape time and ensuring safety of the injury implementing person.

In order to achieve the above object, the present invention provides a handheld terminal having a mobile communication function, including a battery and a central processing unit for information processing, the handheld terminal further including:

a dc-to-ac inverter for converting a dc voltage supplied from the battery into an ac voltage of 30 volts or more; the two electrodes extending out of the handheld terminal shell are respectively connected with the two alternating current output ends of the inverter, and when the two electrodes are connected by a conductor, an alternating current discharge loop is formed; the electronic switch is connected between the battery and the inverter and is used for being switched on and off under the control of the central processing unit; the central processing unit is used for judging whether an input sequence of a user through a keyboard is the same as a preset sequence, and if so, turning on the electronic switch for defense; the central processing unit is also used for judging whether the difference between the current time and the discharge time of the latest alternating current discharge loop is greater than a preset third threshold, and if so, the electronic switch is turned on; the central processing unit is also used for judging whether the difference between the current time and the discharge time of the latest alternating current discharge circuit is greater than a preset fourth threshold, and if so, the electronic switch is closed; wherein the fourth threshold is greater than the third threshold.

Wherein the discharge duration of the alternating current discharge circuit is less than 0.1 second.

In addition, the discharge current of the alternating current discharge circuit is between 8 and 20 milliamperes.

In addition, the hand-held terminal also comprises a current measuring device which is connected in series in the alternating current discharging loop and is used for measuring the magnitude of the alternating current discharging current and reporting the magnitude to the central processing unit;

the handheld terminal also comprises a controllable resistance device which is connected in series between the inverter and the battery or in the alternating current discharging loop and is used for changing the resistance according to the instruction of the central processing unit;

the central processing unit is further configured to determine, after each discharge, a magnitude relationship between a discharge current reported by the current measurement device and a preset first threshold and a preset second threshold, instruct the controllable resistance device to increase the resistance if the discharge current is greater than the first threshold, instruct the controllable resistance device to decrease the resistance if the discharge current is less than the second threshold, and maintain the resistance of the controllable resistance device unchanged if the discharge current is between the first threshold and the second threshold;

wherein the first threshold is greater than the second threshold.

Further, the alternating voltage is 110 volts.

In addition, the hand-held terminal also comprises a keyboard for user input;

the central processing unit is also used for judging whether the input sequence from the keyboard is the same as the preset sequence or not, and if so, the electronic switch is turned on.

In addition, the central processing unit is also used for judging whether the difference between the current time and the discharge time of the latest alternating current discharge loop is larger than a preset third threshold, and if so, the electronic switch is turned on.

In addition, the central processing unit is also used for judging whether the difference between the current time and the discharge time of the latest alternating current discharge circuit is greater than a preset fourth threshold, and if so, the electronic switch is closed; wherein,

the fourth threshold is greater than the third threshold.

In addition, the central processing unit is also used for recording the discharging time after the alternating current discharging loop finishes discharging, and sending the stored discharging time record to a preset number through a short message.

In addition, the handheld terminal can be a mobile phone or a personal digital assistant supporting any one of the following communication systems:

global system for mobile communications, code division multiple access system, wideband code division multiple access system, code division multiple access 2000 system, time division synchronous code division multiple access system, personal hand-held telephone system, trunking communication system.

Through comparison, the technical scheme of the invention is mainly different from the prior art in that a direct current-to-alternating current inverter is added on a handheld terminal for mobile communication, the direct current of a battery in the handheld terminal is converted into alternating current with higher voltage, and the alternating current is discharged through two electrodes extending out of a shell; the ac voltage may be around 110 volts, the current between 8 and 20 milliamps, and the discharge duration less than 0.1 seconds.

In addition, a controllable resistance device is connected in series between the inverter and the battery or in the alternating current discharging loop, the CPU judges whether the detected discharging current is within a specified range after each discharging, and if not, the CPU instructs the controllable resistance device to change the resistance value so as to adjust the current for the next discharging.

Furthermore, the discharge function requires a password to be entered in order to be switched on. After one-time discharge, the discharge can be performed again at intervals, and the discharge function is closed without discharging for a long time.

And recording the discharge time after each discharge, and sending the discharge record to a preset number through a short message.

The difference in the technical scheme brings a relatively obvious beneficial effect, namely, the user can carry out basic defense on the injury implementing person because the discharging function is added.

Because the invention limits the AC voltage to be about 110V, the current to be between 8 and 20 mA, the discharge duration is less than 0.1 second, in this range, people can feel stabbing pain and muscle can produce rigid contraction, but no life safety problem exists, so that the invention does not have fundamental injury to the hurt person who is shocked, but only makes the person feel discomfort in short time, delays the action speed and produces the willingness effect, so that the attacker can strive for precious escape time. The invention acts like a self-defence product such as a "wolf spray" which has been widely used.

Because the CPU can adjust the discharge current according to the recent discharge condition, the invention can realize self-adaptation in various environments, automatically offset the influence of factors such as humidity and the like on the discharge current, and ensure that each discharge can be in a safe and effective range.

Because the discharging function is protected by the password and is automatically closed when the discharging function is not discharged for a long time, accidental injury can be effectively prevented. Because the discharge can be continuously discharged for a plurality of times, the device has higher power for the injury person.

FIG. 1 is a schematic diagram of a prior art DC/AC inverter circuit;

FIG. 2 is a prior art square wave signal generator circuit schematic;

drawings

FIG. 3 is a schematic diagram of a prior art FET driver circuit;

FIG. 4 is a schematic diagram of a prior art MOSFET power switch circuit;

FIG. 5 is a circuit schematic of a prior art DC/AC inverter operating principle;

FIG. 6 is a prior art DC/AC inverter circuit board diagram and finished product look;

FIG. 7 is a schematic diagram of selected components of a prior art DC/AC inverter;

FIG. 8 is a schematic diagram of the prior art placement and connection of DC/AC inverter FETs on a heat sink;

fig. 9 is a circuit schematic diagram of a hand-held terminal according to a first embodiment of the present invention;

fig. 10 is a circuit schematic diagram of a hand-held terminal according to a second embodiment of the present invention;

fig. 11 is a circuit schematic diagram of a hand-held terminal according to a third embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings.

First, it should be noted that the handheld terminal according to the present invention has a mobile function, and may be a mobile phone or a Personal digital assistant in a Global System for mobile Communication ("GSM"), a Code Division Multiple Access ("CDMA") Communication System, a Wideband Code Division Multiple Access ("WCDMA") Communication System, a CDMA2000 Communication System, a time Division Synchronous Code Division Multiple Access ("TD-SCDMA") Communication System, a Personal hand-held telephone System ("PHS") or a trunked Communication System.

Referring to fig. 9, in the first embodiment according to the present invention, the hand-held terminal includes a dc-to-ac inverter, two electrodes protruding out of the case of the hand-held terminal, and an electronic switch, in addition to a battery and a Central Processing Unit (CPU) (not shown) for information Processing.

The dc-ac inverter is used to convert the dc voltage provided by the battery into an ac voltage of 30 volts or more, for example, in the embodiment, the ac voltage is 110 volts. Although the technology of the inverter belongs to the prior art, because the inverter is an important device related to the present invention, in order to make the present specification easier to understand, the structure and the operation principle of the inverter will be briefly described below.

As shown in fig. 1, the inverter is mainly composed of a Metal Oxide Semiconductor (MOS) field effect transistor (fet) and a common power transformer. The output power of the power supply depends on the power of the MOS field effect transistor and the power transformer, so that the complicated transformer winding is avoided, and the power supply is suitable for being adopted in the amateur manufacture of electronic enthusiasts. In order to introduce the working principle and the manufacturing process of the inverter, most parts marked by a dotted line basket in fig. 1, namely a square wave signal generator, a first field effect driving circuit, a second field effect driving circuit, a first MOS field effect transistor power switching circuit and a second MOS field effect transistor power switching circuit, need to be described in detail first.

The square wave signal generator will now be described with reference to fig. 2, where a six-inverter CD4069 is used to form the square wave signal generator, as shown in fig. 2. R1 is a compensation resistor in the circuit, and is used for improving the unstable oscillation frequency caused by the change of the power supply voltage. The oscillation of the circuit is completed by charging and discharging the capacitor C1. The oscillation frequency is f 1/2.2 RC. The maximum frequency of the circuit shown in fig. 1 is: fmax is 1/2.2 × 3.3 × 103 × 2.2 × 10-6 is 62.6 Hz; the minimum frequency fmin is 1/2.2 × 4.3 × 103 × 2.2 × 10-6 is 48.0 Hz. Due to component errors, the actual values may differ slightly. And other redundant inverters, the input end of which is grounded, avoid influencing other circuits.

Referring to fig. 3, a field effect transistor driving circuit is described, wherein the first field effect driving circuit and the second field effect driving circuit in fig. 1 are partially amplified and are circuit diagrams as shown in fig. 3, the circuit receives an oscillation signal from a square wave signal generator, and since the maximum amplitude of the oscillation signal voltage output by the square wave signal generator is 0-5V, in order to fully drive the power switch circuit, as shown in fig. 1 and 3, the oscillation signal voltage is amplified to 0-12V by TR1 and TR 2.

Referring again to fig. 4, a mosfet power switching circuit will be described. The first and second MOS fet power switch circuits in fig. 1 are also circuit diagrams as shown in fig. 4 after being partially amplified, and the working process of the application circuit composed of Complementary Metal-Oxide Semiconductor (C-MOS) fets, i.e., enhanced MOS fets, is briefly described below with reference to fig. 4. The circuit actually uses an enhancement type P channel MOS field effect transistor and an enhancement type N channel MOS field effect transistor which are combined together, and a dotted line block diagram is already marked in figure 4. When the input terminal is at a low level, which is the case of the left circuit diagram in fig. 4, the P-channel MOS fet is turned on, and the output terminal is connected to the positive electrode of the power supply. When the input terminal is at a high level, which is the case of the right circuit diagram in fig. 4, the N-channel MOS fet is turned on, and the output terminal is connected to the power ground. In this circuit, the P-channel mosfet and the N-channel mosfet always operate in opposite states, and the phase input terminal and the phase output terminal thereof are opposite. By this way a large current output can be obtained. Meanwhile, due to the influence of leakage current, the gate voltage is not yet 0V, and usually, when the gate voltage is less than 1 to 2V, the MOS field effect transistor is turned off. The turn-off voltages of different field effect transistors are slightly different. And because of this, the circuit can not cause the short circuit of the power supply because the two tubes are conducted simultaneously.

Through the above analysis, the first mosfet power switching circuit, the second mosfet power switching circuit and the transformer are combined to form the main components of the DC/AC inverter, and the operation principle thereof will be described in detail with reference to fig. 5. Since the operating principle of the MOS field effect transistor power switching circuit has been described above, a large current output can be obtained by using the MOS field effect transistor power switching circuit and the MOS field effect transistor power switching circuit separately. As shown in fig. 5, if the first mosfet power switching circuit and the second mosfet power switching circuit are used in combination, a larger current output can be generated. The two are combined with a transformer, and when the alternating signal with low voltage, large current and 50Hz frequency generated by the two passes through a low-voltage winding of the transformer, high-voltage alternating voltage is induced on the high-voltage side of the transformer, so that the conversion from direct current to alternating current is completed. It should be noted here that in some cases, such as when the oscillating portion stops operating, the low-voltage side of the transformer sometimes has a large current flowing through it, so that the fuse of the circuit cannot be omitted or shorted.

Finally, the circuit board is shown in fig. 6. The components used can be referred to in fig. 7. The transformer for the inverter adopts a finished product power transformer with 12V secondary, 10A current and 220V primary voltage. The maximum drain current of the P-channel MOS field effect transistor (2SJ471) is 30A, and when the field effect transistor is conducted, the resistance between a drain electrode and a source electrode is 25 milliohms. At this time, if a current of 10A is passed, a power consumption of 2.5W is generated. The maximum drain current of the N-channel MOS field effect transistor (2SK2956) is 50A, when the field effect transistor is conducted, the resistance between the drain and the source is 7 milliohm, and at this time, if the current of 10A passes, the consumed power is 0.7W. Therefore, under the same working current, the calorific value of 2SJ471 is about 4 times that of 2SK 2956. This should be noted when considering a heat sink. Fig. 8 shows the position distribution and connection of the inverter field effect transistor of the prior art on the radiator (100mm × 100mm × 17 mm). Although the fet does not generate much heat when operating in the on-off state, the heat sink selected for this purpose is somewhat larger for safety reasons.

The structure and the operation principle of the inverter according to the present invention are described above, and the electrode and the electronic switch according to the present embodiment will be described next.

As shown in fig. 9, two electrodes extending out of the hand-held terminal housing are connected to two ac output terminals of the inverter, respectively, and it can be understood that an ac discharge circuit is formed when the two electrodes are connected by a conductor. In the present embodiment, the discharge duration of the ac discharge circuit is less than 0.1 second, and the discharge current of the ac discharge circuit is between 8 and 20 milliamps.

An electronic switch is connected between the battery and the inverter for switching on and off under the control of the CPU.

Therefore, in the embodiment, the direct current of the battery in the handheld terminal is converted into the higher-voltage alternating current by adding the direct-current to alternating-current inverter on the handheld terminal, and the high-voltage alternating current is discharged through the two electrodes extending out of the shell, so that the alternating voltage of about 110 volts, the current intensity of 8-20 milliamperes and the discharge duration time of less than 0.1 second can be achieved. Because the discharge function is added, the user can basically defend the injury person.

It should be noted that, in this embodiment, the ac voltage is limited to about 110v, the current is limited to 8 to 20 ma, and the discharge duration is less than 0.1 s, in this range, people will feel stabbing pain and muscle will contract with rigidity, but there is no life safety problem, so there will not be fundamental harm to the hurt person who is shocked, but the hurt person will feel discomfort for a short time, the action speed is delayed, and the victory effect is generated, so that the attacker can strive for valuable escape time.

Next, a second embodiment of the present invention will be explained with reference to fig. 10.

As shown in fig. 10, the handheld terminal of the second embodiment further includes a current measuring device and a controllable resistance device in addition to the dc-to-ac inverter, the two electrodes extending out of the housing of the handheld terminal, and the electronic switch.

Specifically, the current measuring device is connected in series in the alternating current discharge circuit and used for measuring the magnitude of the alternating current discharge current and reporting the magnitude to the CPU. The controllable resistance device is connected in series between the inverter and the battery and used for changing the resistance according to the instruction of the CPU. The controllable resistance device may be one device or a small circuit made up of a plurality of devices.

It should be noted that the controllable resistance device is not limited to be disposed between the inverter and the battery as described above, and as shown in fig. 11, the controllable resistance device may be disposed in the ac discharge circuit in the third embodiment of the present invention.

Correspondingly, different from the first embodiment, in the second and third embodiments, the CPU is further configured to determine, after each discharge, a relationship between a discharge current reported by the current measurement device and a preset first threshold (upper limit) and a preset second threshold (lower limit), and if the discharge current is greater than the first threshold, that is, the upper limit, instruct the controllable resistance device to increase the resistance, thereby reducing the current; conversely, if the discharge current is less than the second gate, i.e., the lower limit, the controllable resistance device is instructed to decrease the resistance, thereby increasing the current. The resistance of the controllable resistance device is maintained constant if the discharge current is between the first and second thresholds. The skilled person will appreciate that the first threshold is greater than the second threshold.

Therefore, in the third and fourth embodiments, based on the first embodiment, a controllable resistance device is further connected in series between the inverter and the battery or in the ac discharge loop, the CPU determines whether the detected discharge current is within a specified range after each discharge, and if not, instructs the controllable resistance device to change the resistance value to adjust the current for the next discharge, so as to ensure that the discharged current meets the predetermined requirement. In other words, the CPU can adjust the discharge current according to the recent discharge condition, so the invention can realize self-adaptation under various environments, thereby automatically offsetting the influence of factors such as humidity and the like on the discharge current and ensuring that each discharge can be in a safe and effective range.

In the fourth embodiment of the present invention, a password starting function is added by using a keyboard for user input on the handheld terminal. Specifically, the CPU can be used for determining whether or not the input sequence of the user through the keyboard is the same as a predetermined set sequence (i.e., password), in addition to the above-described use. If yes, an electronic switch is turned on for defense. In addition, in the fourth embodiment, the CPU may be further configured to determine whether a difference between the current time and the discharge time of the last ac discharge circuit is greater than a preset third threshold, and if so, turn on the electronic switch. The CPU is also used for judging whether the difference between the current time and the discharge time of the latest alternating current discharge circuit is larger than a preset fourth threshold, and if so, the electronic switch is closed. It will be appreciated that the fourth threshold is greater than the third threshold. In this embodiment, the discharge function requires a password to be entered to turn on. And, ensure that can discharge again after a certain time (namely third threshold) after once discharging, and do not discharge for a long time, turn off the discharge function automatically. Because the discharging function is protected by the password and is automatically closed when the discharging function is not discharged for a long time (namely, the fourth threshold), accidental injury can be effectively prevented. Meanwhile, because the discharge can be continuously carried out for many times, the device has higher power for the injury person.

In a fifth embodiment of the present invention, the CPU is further configured to record the discharge time after the ac discharge circuit completes the discharge, and send the stored discharge time record to a preset number through a short message. The method can be used as strong evidence because the discharge record is automatically stored and is automatically sent to a designated number (such as the number of a police party) in time. If the handheld terminal has a positioning function, the discharging position can be recorded at the same time and the discharging position can be sent to the designated number by means of short messages and the like, so that timely rescue of police or relatives and friends is facilitated.

The structure of the handheld terminal of the present invention is described above, and the working principle of the present invention is further described below in order to make the differences and effects of the present invention easier to understand. When the user is threatened, the user can continuously input a preset password within 3 seconds on the user operation interface of the terminal equipment, the electronic switch is closed, the function of the terminal electric shock device is started immediately, and 110V alternating voltage is generated between the two electrodes A and B on the alternating current side.

Then, when the electrode A, B touches the body threatening the manufacturer at two points, the rapid discharge, 110V AC, can knock down the body. Meanwhile, the CPU rapidly cuts off the electronic switch within 0.1 second through the discharging behavior detected by the terminal battery, and the limit of injury to a human body under the condition of electric shock is 0.2 second according to common knowledge, so that the 0.1 second discharging time can play a self-defense role and ensure that the discharging cannot cause serious injury to the opposite side.

Then, after 2 seconds, the CPU automatically activates the electronic switch, whereby the user can continuously give a self-defence electric shock to the attacker.

The power consumption of the ac terminals is calculated as follows:

p ═ U/2R ═ 110V/2 ═ 100,000 ohm ═ 0.06w ═

Where P is power, U is voltage, and R is resistance

If the body resistance is calculated according to the common 100K ohm and the conversion efficiency is calculated according to the conservative calculation of 20%, 0.06/20% is 0.3 w.

On the other hand, the power supply capacity of the mobile phone battery is calculated as follows:

the mobile phone battery is calculated according to 600mah, the voltage output of the mobile phone battery is calculated according to 3.5V, and the power supply time is as follows:

3.5V 600 Amp/1000/0.3 w 2.1 h

Therefore, the common mobile phone battery can ensure the continuous output of the electric shock power.

When the defense is finished, the electric shock function is closed after the user inputs the electric shock function password again.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

Claims

1. A hand-held terminal having a mobile communication function, comprising a battery and a central processing unit for information processing,

It is characterized in that the handheld terminal also includes:

A DC-to-AC inverter for converting the DC voltage provided by the battery into an AC voltage above 30 volts;

Two electrodes protruding from the shell of the handheld terminal are respectively connected to the two AC output terminals of the inverter, and an AC discharge circuit is formed when the two electrodes are connected by conductors;

an electronic switch, connected between the battery and the inverter, for turning on and off under the control of the central processing unit;

The central processing unit is used to judge whether the input sequence of the user through the keyboard is the same as the predetermined sequence, and if so, turn on the electronic switch for defense;

The central processing unit is also used to judge whether the difference between the current moment and the latest discharge time of the AC discharge circuit is greater than the preset third threshold, and if so, turn on the electronic switch; the central processing unit is also used to judge the current moment Whether the difference with the discharge time of the latest AC discharge circuit is greater than a preset fourth threshold, and if so, turn off the electronic switch; wherein, the fourth threshold is greater than the third threshold.

2. The handheld terminal according to claim 1, wherein the discharge duration of the AC discharge circuit is less than 0.1 second.

3. The handheld terminal according to claim 1, characterized in that, the discharge current of the AC discharge circuit is between 8 and 20 mA.

4. The hand-held terminal according to claim 3, characterized in that, the hand-held terminal also includes a current measuring device connected in series in the AC discharge circuit, for measuring the magnitude of the AC discharge current, and sending to the central Processor reporting;

The handheld terminal also includes a controllable resistance device, which is connected in series between the inverter and the battery or in the AC discharge circuit, and is used to change the resistance according to the instructions of the central processing unit;

The central processing unit is also used for judging the relationship between the discharge current reported by the current measuring device and the preset first and second thresholds after each discharge, and if the discharge current is greater than the first threshold, it indicates that the increasing the resistance of the controllable resistance device, instructing the controllable resistance device to reduce resistance if the discharge current is less than a second threshold, and maintaining the resistance of the controllable resistance device if the discharge current is between the first and second thresholds Change;

Wherein, the first threshold is greater than the second threshold.

5. The handheld terminal according to claim 1, wherein the AC voltage is 110 volts.

6. The handheld terminal according to any one of claims 1 to 5, wherein the central processing unit is also used to record the discharge time after the discharge of the AC discharge circuit is completed, and record the stored discharge time Send via SMS to a pre-set number.

7. The handheld terminal according to any one of claims 1 to 5, wherein the handheld terminal can be a mobile phone or a personal digital assistant supporting any of the following communication systems:

Global System for Mobile Communications, Code Division Multiple Access System, Broadband Code Division Multiple Access System, Code Division Multiple Access 2000 System, Time Division Synchronous Code Division Multiple Access System, Personal Handy Phone System, Trunking Communication System.