200810187 九、發明說明： w 【發明所屬之技術領域】 本發明係有關一種鋰電池充電系統，特別是一種利用微控 制器控制充電之鋰電池充電系統。 【先前技術】 隨著目前無線通訊的盛行及科技的趨勢，手持式裝置輕 巧、便利及高機動性之特色，帶動了手持式裝置之普及與流 • 行，因此，為了因應手持式裝置實用便利性的需求，越來越 多有關手持裝置充電電池之商機曰益崛起。為了滿足手持式 裝置待機時間長之使用者需求，大容量之充電電池為一十分 重要之必備配件；又，為了能充分使用充電電池的使用效率， 使用一完全充飽之充電電池相對的較符合經濟效益，然而， 如果無法得知電池是否已經充電完成，且無法自動停止充 電，很容易就會降低電池壽命、損壞電池、或發生危險。因 此，如何自動檢知電池充電狀態以及電池目前電量為一迫切 解決之課題。 • 習知手持式裝置之充電方式係於手持式裝置内另增加一 充電晶片，用以控制並處理充電電池之充電狀態及需求，然 而，隨著手持式裝置小型化的需求，且因電路板上所固設之 電子組件數量會因手持式設備之高機能而增加，所以對於手 持式裝置之應用電路之佈局及尺寸亦日漸被要求，因此，如 何在自動檢知電池充電狀態以及電池目前電量且不影響充電 效能之前提下，縮小充電系統之尺寸為一當前之要務。 【發明内容】 200810187 奋了解決上述問題，本發明目的之一係在提供一種鋰電池 電控制系統，將充電線路之控制程式整合在手持式裝置原 侗：：之微處理器中，可省略外接充電晶片之費用、達到降 低零件成本之功效。 s月之又一曰的係在提供一種鋰電池充電控制系統，具 、、、佑丑手持式產品開發之時間及大幅降低設計成本之優點。200810187 IX. INSTRUCTIONS: w TECHNICAL FIELD The present invention relates to a lithium battery charging system, and more particularly to a lithium battery charging system that uses a micro controller to control charging. [Prior Art] With the prevalence of wireless communication and the trend of technology, the advantages of lightweight, convenient and highly maneuverable handheld devices have driven the popularity and flow of handheld devices. Therefore, in order to meet the practical convenience of handheld devices. Sexual demand, more and more business opportunities for rechargeable devices for handheld devices have risen. In order to meet the needs of users with long standby time of handheld devices, large-capacity rechargeable batteries are an important and necessary accessory; in addition, in order to fully utilize the efficiency of rechargeable batteries, a fully charged rechargeable battery is used. It is economical. However, if you can't know if the battery has been fully charged and you can't stop charging automatically, it will easily reduce battery life, damage the battery, or cause danger. Therefore, how to automatically detect the state of charge of the battery and the current battery power is an urgent problem. • The charging method of the conventional handheld device is to add a charging chip to the handheld device to control and handle the charging state and demand of the rechargeable battery. However, with the miniaturization of the handheld device and the circuit board The number of electronic components installed on the device will increase due to the high functionality of the handheld device. Therefore, the layout and size of the application circuit for the handheld device are increasingly required. Therefore, how to automatically detect the battery charging state and the current battery power. It is a current priority to reduce the size of the charging system before it affects the charging performance. SUMMARY OF THE INVENTION 200810187 To solve the above problems, one of the objects of the present invention is to provide a lithium battery electric control system, the control program of the charging line is integrated in the microprocessor of the handheld device: the external device can be omitted The cost of charging the chip and reducing the cost of parts. Another step in the month is to provide a lithium battery charging control system, which has the advantages of the development time of the handheld products and the significant reduction in design cost.
户理=發明之又_目的係在提供一種鋰電池充電控制系統，微 :、周/係利用一料寬度調變之控制方式調變控制單元之作 込功，可依據不同電池容量之鋰電池彈性調變充電單元所提供之電 力’使之調變成鋰電池充電所需之定電流或定電壓。 %=I達到上述目的，本發明之—實施例提供-義電池充 統，其包含一微處理器；一控制單元，其係與微處 ::性連接，並接收來自微處理器之一控制信號，控制此 ^制早70作動，其中，此控制信號為一脈波寬度調變訊號 以控制控制料職性之作動；—充電m係# 性連接，藉由觀控解元之作動週期，將充電單元所提供 1 調變成链電池充電所需之電流或電壓；及__電壓仙】電路、，^含、 -輸入端用以接收-類比電壓值，及—輸出端與微處理^ 性連接，用則貞載電池目前之電量，絲此f量傳駐微處理哭 做判斷’即時地判斷驗電池所需使用之充電方式及充電過程 = 池之狀態。田 ^ 以下藉由具體實施例配合所附的圖式詳加說明，當更容易瞭 創作之目的、技術内容、特點及其所達成之功效。 、 【實施方式】 以下係以-較佳實施例來說明本發明之鐘電池充電控制系 統0 6 200810187 晴參閱第1圖，為根據本發明實施之鋰電池充電控制系統方塊示 意圖。如圖中所示，鋰電池充電控制系統1〇包含_微處理= (miCropiOcessor) 100 ,用以處理並控制手持式裝置之作動；一電^ 偵測電路400，其一端係與一鋰電池20電性連接，另一端與微處理^ 電性連接，用以偵測鋰電池2〇目前之充電狀態及鋰電池如内之 電壓；一控制單元200,其電性連接微處理器1〇〇; 一充電單元3〇〇， 其、係電性連接控制單元2〇〇，另一端與鋰電池2〇電性連接。 、於此實施例中，電壓偵測電路400在鋰電池2〇欲充電前，會先 1 貞測鍾電池20内部目前之電量。，透過電壓偵測電路_内部之一 類，數位轉換電路（細log_t〇瓜_ c〇nverter，MC)將鐘電池如 内部之‘由-類比（analog)電壓值轉換成一數位（digital)電壓值， 並透過電性連接將此數位電壓值傳送至微處理器1〇〇進行訊號之判斷 及處理。若彳政處理裔1〇〇判斷I里電池2〇此時之電量需進行充電之動 作二則微處理器1〇〇送出一作動控制訊號至控制單元2〇〇，其中，控 制單元200為-開關控制線路（如至少—電晶體）或一開關，用以控 制充電單元3GG作動；當控制單元测接收到微處理器⑽之作動控 孔號，要求致能（enabIe)充電單元3〇〇對鐘電池2〇充電時，控制 早兀2〇〇導通以形成一通路並驅動充電單元3〇〇動作，其中，來自微 處理器100之一作動控制訊號係利用微處理器100 0部之一拿刃體 (fm肅are)(圖中未示◊之一脈波寬度調變⑽阳w趣M_ati〇n， 一力月b以并^控制單元200作動之週期（dutycycIe);藉由調變 4工制單7^ 200之作動週期，將充電單元3〇()所提供之電源調變成鐘電 池20充電所需之電流或電屡；另外，充電單幻⑽包含—電力輸入 皐（如插頭或電細之通用序列埠（咖爾幼! Seriai勤，USB))以取得 電力對链電池2G充電。在充電過程巾，電壓侧電路4GG同步地谓 =¾池20之狀恶及^之大小，且不騎地將、之值傳送至微處 7 1〇0以判斷充電是否完畢；當電壓偵測電路4〇0侧到等於 ’大於4·2伏特之同時，微處理器1〇〇送出一作動控制訊號要求控制 7 200810187 單元200控制充電單元300使之不繼續對鋰電池2〇進行充電之動作。 可以理解的’經電池充電控制系統10係透過不斷地摘測厂跡及致能充 電單= 300而完成鐘電池20充電之過程。又，微處理器棚更包含 -計時電路（timer·) 1〇2,用以保護電力模組3G若在預定時間内仍無 法達到欲充電之電量時，則表示充電過程有錯誤發生導致充電失敗， 則中斷充電之動作。 —凊麥閱第2目，為根據本發明一實施之鐘電池充電流程圖。於此 實施=中，當欲對電池進行充電時，電胸貞測電路會_此鋰電 池目狀電量。（步，驟500)，用以判斷應對之充電方式（步驟观》 其充電階段有三··預先充電隨、定電流充紐段、以及定電壓充電 階段。若細到小於3·〇伏特，則進入預先充電（p㈣^职）階 段（步驟504)’利用Η)毫安培（mA)的電流量對此鐘電池進行預先 充電的動作，若在預先設定之預先充翁護時間（15分鐘）内將此鐘 電池充電至‘大於3.G伏特，咖先充電階段完成；若預先充電過 程超過15分鐘且。仍未大於3·〇伏特，則表示此次充電過程發生錯 誤導致充電失敗。若躺到‘介於3 G伏特至41伏特之間，則進入Household management = invention again _ purpose is to provide a lithium battery charging control system, micro:, week / system using a material width modulation control mode modulation control unit for the work, can be based on different battery capacity of the lithium battery The power provided by the elastic modulation charging unit is adjusted to the constant current or constant voltage required for charging the lithium battery. %=I achieves the above object, and an embodiment of the present invention provides a battery pack including a microprocessor; a control unit that is connected to the micro: and is controlled by one of the microprocessors. The signal is controlled to operate as early as 70, wherein the control signal is a pulse width modulation signal to control the operation of the control material; the charging m system is connected, and the actuation cycle is controlled by the control unit. Adjust the current provided by the charging unit into the current or voltage required for charging the chain battery; and __voltage] circuit, ^, - input to receive - analog voltage value, and - output and micro-processing Connect, use the battery's current power, the wire is transferred to the micro-processing, crying to judge 'immediately determine the battery charging mode and charging process = the state of the pool. Tian ^ The following is a detailed explanation of the specific embodiment with the attached drawings, which makes it easier to create the purpose, technical content, characteristics and the effects achieved. [Embodiment] Hereinafter, a clock battery charging control system of the present invention will be described with reference to a preferred embodiment. FIG. 1 is a block diagram showing a lithium battery charging control system according to an embodiment of the present invention. As shown in the figure, the lithium battery charging control system 1 includes _micro processing = (miCropiOcessor) 100 for processing and controlling the operation of the handheld device; and an electric detecting circuit 400 having one end connected to a lithium battery 20 Electrically connected, the other end is connected to the micro-processor to electrically detect the current state of charge of the lithium battery 2 and the voltage of the lithium battery; a control unit 200 electrically connected to the microprocessor 1; A charging unit 3 is electrically connected to the control unit 2〇〇, and the other end is electrically connected to the lithium battery 2〇. In this embodiment, the voltage detecting circuit 400 first measures the current power inside the battery 20 before the lithium battery 2 is intended to be charged. Through the voltage detection circuit _ internal class, the digital conversion circuit (fine log_t _ c_nverter, MC) converts the clock battery into an internal analog voltage value into a digital voltage value. The digital voltage value is transmitted to the microprocessor 1 through an electrical connection for signal determination and processing. If the ruling party 1 determines that the battery in the I battery needs to be charged, the microprocessor 1 sends an actuation control signal to the control unit 2, wherein the control unit 200 is - a switch control circuit (such as at least - a transistor) or a switch for controlling the charging unit 3GG to operate; when the control unit measures the receiving of the microprocessor (10) as a motion control hole number, it is required to enable (enabIe) the charging unit 3 When the battery is charged, the control is turned on to form a path and drive the charging unit 3, wherein one of the control signals from the microprocessor 100 is taken by one of the microprocessors 100. Blade body (fm isare) (not shown in the figure is a pulse width modulation (10) Yang w fun M_ati〇n, one force month b to control the unit 200 to operate the cycle (dutycycIe); by modulation 4 The operating cycle of the system 7 ^ 200, the power supply provided by the charging unit 3 〇 () is converted into the current or electricity required to charge the battery 20; in addition, the charging single magic (10) contains - power input 皋 (such as plug or The general sequence of electric fines (Cal's young! Seriai Qin, USB)) The electric power charges the chain battery 2G. In the charging process, the voltage side circuit 4GG synchronously refers to the size of the pool and the size of the pool, and does not ride the ground, and the value is transmitted to the micro point 7 1〇0 to judge Whether the charging is completed; when the voltage detecting circuit 4〇0 side is equal to 'greater than 4·2 volts, the microprocessor 1 sends an actuation control signal request control 7 200810187 The unit 200 controls the charging unit 300 so as not to continue The operation of charging the lithium battery 2 。. It can be understood that the battery charging control system 10 completes the charging process of the clock battery 20 by continuously extracting the factory trace and enabling the charging list = 300. The timer circuit (timer·1) is included to protect the power module 3G from the charging operation if the charging process fails to reach the amount of power to be charged within a predetermined time. - The second item of the present invention is a charging circuit diagram of a clock battery according to an embodiment of the present invention. In this implementation, when the battery is to be charged, the electric chest measuring circuit will have a power of the lithium battery. Step, step 500), In order to judge the charging method (step view), the charging stage has three pre-charging, constant current charging, and constant voltage charging. If it is less than 3·〇V, it will enter pre-charging (p(4)) At the stage (step 504), the amount of current in milliamperes (mA) is precharged for the battery, and the battery is charged to 'greater than the pre-set pre-charge time (15 minutes). 3. G volt, the coffee charging phase is completed; if the pre-charging process exceeds 15 minutes and still not more than 3 〇 volts, it means that the charging process has an error that causes the charging to fail. If lying to 'between 3 G volts Between 41 volts, enter
定電流充電（Constant Current Charging)階段（步驟 5〇4)，利用 〇 5C 的定電流（K>欲％電之Μ電池容量/一小時，假設欲充電之鐘電池容 量為500mAh，則1C的充電電相當於5〇〇mA)對此鋰電池進行定 電流充電’其中，此定電流係利用微處理器之韋刃體内一脈波寬度調變 (Pulse Width Modulation，PWM)功能以調變控制單元作動之週期 (duty cycle)，藉由調變控制單元之作動週期（步驟5〇6)，將充電單 元所提供之電力調變成鋰電池充電所需之定電流，若在預先設定之定 電流充電保護時間（90分鐘）内將此鋰電池充電至^^大於41伏特 (步驟508) ’則定電流充電階段完成；反之，若定電流充電過程超過 90分鐘且心7仍未大於4.1伏特，則表示此次充電過程發生錯誤導致 充電失敗。若偵測到大於4·1伏特，則進入定電壓充電（c〇ns Voltage Charging)階段（步驟504)，利用4·2伏特之定電壓對此鋰= 8 200810187 電’其中’此定電壓亦係湘微處理11之動體内之 ^力能調變控制單元作動之週期（步驟5G6)，藉由調變控制單元 週娜充電單元所提供之電力調變雜電池充騎需之定電 ^雷m行定電壓充電（步驟則，此時充電電流會慢慢下降，當 ^私机IV至(UC時’且在預先設定之定電壓充電保護時間⑼分 勺比2此鐘a池充電至匕7、等於4·2伏特（步驟5G8)，則定電壓充 ^白、又完成；反之’若定電壓充電過程超過90分鐘且^仍未大於 •伏特’ I彳麵此次充電過程發生錯誤導致充電失敗。Constant Current Charging stage (step 5〇4), using 〇5C constant current (K> %% Μ battery capacity / one hour, assuming that the battery to be charged is 500mAh, then 1C charging The electric power is equivalent to 5 mA), and the lithium battery is subjected to constant current charging. Among them, the constant current is controlled by a pulse width modulation (PWM) function of the microprocessor. The cycle of the unit actuation, by adjusting the actuation period of the control unit (step 5〇6), the power provided by the charging unit is converted into a constant current required for charging the lithium battery, if a predetermined current is set. Charge the lithium battery to a voltage greater than 41 volts (step 508) during the charge protection time (90 minutes). Then, if the constant current charging process exceeds 90 minutes and the heart 7 is still less than 4.1 volts, then Indicates that an error occurred during this charging process that caused the charging to fail. If greater than 4·1 volt is detected, enter the stage of constant voltage charging (c〇ns Voltage Charging) (step 504), and use the constant voltage of 4·2 volts for this lithium=8 200810187 electric 'where' the constant voltage is also The cycle of the force modulation control unit in the moving body of the Hunan micro-processing 11 (step 5G6), by the power supply of the modulation control unit Zhouna charging unit, the battery is charged and charged. Thunder m line constant voltage charging (step, then the charging current will slowly drop, when ^ private machine IV to (UC when 'and at a predetermined fixed voltage charge protection time (9) scoop than 2 this clock a pool charge to匕7, equal to 4·2 volts (step 5G8), the constant voltage is charged and completed; otherwise, if the voltage charging process exceeds 90 minutes and ^ is still not greater than • volts, the charging process is incorrect. Charging failed.
其中，充電三階段（預先充電階段、定電流充電階段、以及定電 &充電階段）之充電保護時間長短係於微處理器之勒翻預先設定， ^根據不_電池之特性而作調整，搭配計時電路可於充電過程當中 鲞生錯誤時，停止充電之動作以保護鋰電池。 /綜合上述，於此實施例中，鐘電池充電過程中，電壓侧電路 係=斷地__池之電量（步驟則關斷且選擇_池所需之 3方式（步驟502、504)，再透過微處理器内之pWM功能^控 2几（步驟)’且搭配充電單擔電力調變成合適之定電流或定 電壓對崎池充電(步驟5G8);透過不斷重複步驟_、繼、綱、 5〇6、及508直至鋰電池充電完成。 明參閱第3圖，為根據本發明實施之一實施例之手持式裝置架構 之方塊示意圖。如圖所示，手持式裝置丨係包含：一殼體（圖中未示）； 一中央控制模組40，設置於殼體内且至少包含一微處理器，其中，此 微處理器係用以控制且處理手持式裝置〗之所有應用程序及;|乍動；一 應用模組70，其係設置於殼體内，並且與中央控制模組4〇電性連接； 一電力模組3G (如鋰電池），其設置於殼體内用以提供手持式裝置工 作動所需之電力；一顯示模組50,係設置於殼體内，且與中央控制模 組40電性連接；一充電控制模組6〇，係設置於殼體内且其」^與二 央控制模組40電性連接，其中，充電控制模組6〇包含：一電壓偵測 9 200810187 :二其::端，力模組3〇電性連接’用以偵測電力模組30目前 = 而触處理器電性連接，用以將電力模組30之電量傳 达至微處理器做判斷；及一批生丨留一 屯里得 以接收來自ft,理^ / 其 與微處理器電性連接 收；自U處理态之一脈波寬度調變訊號。 壓』:持2置上之電力模組3〇欲充電時，充電控制模組60之電 、“早疋日制電力模組3〇内部目前之電量，透過電界星_ =部之-類比數位轉換電路將電力模組％内部之電量由:類比= 、、=40之掀處理盗進行訊號之判斷及處理。若 ft 〇此時之電量需進行充電之動作，則微處理器送出一乍: :，元接收到微處理器之作動控制訊號，要求致能充電器2對“ m充r時’ t制單元導通_成—通路並驅動充電器2動作’ :、，來自微處職之脈波寬度靖訊細糊變 吴組30充電所需之電流或電麼,·另外，充電器2包含一電力 埠（如插頭或電腦之通用序列璋（Uni聰心細抑 ^ 電力模組30充電。在充魏程中，電翻測電路同步地谓二 :力核組30之狀態及電量之大小，且不間斷地將電量訊號傳送至微 ，理益以判斷充電是否完畢；#Μ_電路伽彳到電力模组如之 電量等於或大於4.2伏特之同時，中央控制模組4〇之微處理 一 作動控制訊號要求控制單元控制充電器2使之不繼續對電力模紐 進^充電之動作。可以理解的，充電控制模組6〇及中央控細且奶 係透過不__電力模組3G之電量及週期性地致能充電器 成電力拉組30之充電。又，中央控制模組4〇之微處理器更包含—= 時電路，用以保護電力模組％若在預定時間⑽無法翻欲充電^ 200810187 ’則中斷充電之動 電量時，赚轉電難有錯誤射導致充電失敗 系統，其係利用一電壓偵測電 變訊綱-The charging protection time of the three stages of charging (precharge phase, constant current charging phase, and power saving & charging phase) is preset by the microprocessor, and is adjusted according to the characteristics of the battery. With the timing circuit, when the error occurs during the charging process, the charging action is stopped to protect the lithium battery. / In summary, in this embodiment, during the charging process of the clock battery, the voltage side circuit system = the power of the ground__ pool (the step is to turn off and select the 3 modes required for the pool (steps 502, 504), and then pass through. The pWM function in the microprocessor is controlled by 2 (steps)' and charged with the charging single-load power to become a suitable constant current or constant voltage to charge the Saki pool (step 5G8); repeat the steps _, success, outline, 5 〇6, and 508 until the charging of the lithium battery is completed. Referring to Figure 3, there is shown a block diagram of a handheld device architecture in accordance with an embodiment of the present invention. As shown, the handheld device includes: a housing A central control module 40 is disposed in the housing and includes at least one microprocessor, wherein the microprocessor is used to control and process all applications of the handheld device; An application module 70 is disposed in the housing and electrically connected to the central control module 4; a power module 3G (such as a lithium battery) disposed in the housing for providing handheld The power required for the operation of the device; a display module 50, The device is disposed in the housing and electrically connected to the central control module 40. A charging control module 6 is disposed in the housing and electrically connected to the central control module 40. Module 6〇 includes: a voltage detection 9 200810187: two:: end, force module 3〇 electrical connection 'to detect the power module 30 current = and the processor is electrically connected to power The power of the module 30 is transmitted to the microprocessor for judgment; and a batch of raw materials is received from the ft, and the power is electrically connected to the microprocessor; the pulse width is one of the U processing states. Modulation signal: Pressure: Holds 2 power modules 3 〇 When charging, the charging control module 60 is powered, “The current power of the 3D power module in the early days, through the electric boundary star _ = The analog-to-digital conversion circuit treats the internal power of the power module % by: analogy = , , and =40 to process the judgment and processing of the pirate signal. If the ft 〇 power needs to be charged at this time, the microprocessor Send a 乍: :, yuan receives the microprocessor's actuation control signal, requires the charger 2 to "m charge r 't system conduction _ into - path and drive charger 2 action ':,, from the micro-service pulse width Jing News fine change Wu group 30 charge required current or electricity, · In addition, charger 2 Include a power 埠 (such as the plug or computer's universal sequence 璋 (Uni Conscience fine ^ power module 30 charging. In the charging process, the electrical volts circuit synchronously said two: the state of the force core group 30 and the amount of power, and Uninterruptedly transmit the power signal to the micro, and benefit to determine whether the charging is completed; #Μ_电路伽彳 to the power module, if the power is equal to or greater than 4.2 volts, the central control module 4〇 micro-processing The control signal requires the control unit to control the charger 2 so as not to continue charging the power module. It can be understood that the charging control module 6 and the central control unit and the milk system pass through the power of the power module 3G and periodically enable the charger to charge the power group 30. Moreover, the microprocessor of the central control module 4 further includes a -= circuit for protecting the power module%. If the power module cannot be turned over at the predetermined time (10), the power is lost when the power is turned off. There is a faulty shot that causes the charging failure system, which uses a voltage to detect the electrical converter -
^，將充電單元職供之電_變賴魏錢顺之糕或電塵^ =I=f咖峨谓糊轉㈣動週期，達 X上所述之Λ Μ例僅係為說明本發明之技術思想及特 點，其目的在使熟習此項技藝之人士能夠瞭解本發明之内容 亚據以實施’當不能以之限定本發明之專利範圍，即大凡依 本發明所揭*之精制叙均#變化或修飾，仍應涵蓋在本 發明之專利範圍内。 【圖式簡單說明】 第1圖為根據本發明實施之鋰電池充電控制系統方塊示意圖。 第2圖為根據本發明實施之一實施例之鐘電池充電流程圖。 第3圖為根據本發明實施之一實施例之手持式裝置架構之方塊示意圖。 【主要元件符號說明】 1 手持式裝置 2 充電器 10 鋰電池充電控制系統 20 鋰電池 11 200810187 微處理器 計時電路 控制單元 充電單元 電壓偵測電路 電力模組 中央控制模組 顯示模組 充電控制模組 應用模組 步驟 步驟 步驟 步驟 步驟^, the power supply unit of the charging unit _ 魏 魏 Wei Qianshun cake or electric dust ^ = I = f curry is said to turn (four) dynamic cycle, up to X described above The technical idea and the purpose of the present invention are to enable those skilled in the art to understand the contents of the present invention to implement the patent range which cannot be limited by the invention, that is, the refinement of the invention according to the invention. Variations or modifications are still intended to be encompassed within the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram showing a lithium battery charging control system according to an embodiment of the present invention. 2 is a flow chart of charging a clock battery according to an embodiment of the present invention. 3 is a block diagram of a handheld device architecture in accordance with an embodiment of the present invention. [Main component symbol description] 1 Handheld device 2 Charger 10 Lithium battery charging control system 20 Lithium battery 11 200810187 Microprocessor timing circuit control unit Charging unit Voltage detection circuit Power module Central control module Display module charging control mode Group application module step step step step