201123935 六、發明說明： 【發明所屬之技術領域】 [0001] 本發明涉及一種音量調節技術，尤其涉及一種音量調節 系統。 【先前技術】 [0002]目前，移動電話、可檇式音樂播放裝置等電子儀器都包 括有一音頻驅動電路用來驅動喇〇八、耳機等聲音產生裝 置發聲。一般地’音頻驅動電路包括一數模轉換器和一 放大器。數模轉換器接收數位聲音訊號，並將其轉換成 類比訊號。放大器放大類比訊號並提供給聲音產生裝置 據以發聲。 [〇〇〇3]實際應用中’喇叭或耳機等聲音差生裝置都省最大輸出 音量限制。若超過最大輪出音量限制就會產生破音的現 象。這種破音的現象常常會讓使用者很困擾，而且有可 能破壞某些高敏感度的元件》 【發明内容】 [0004] 有鑒於此，有必要提供一種可防止破音現象產生的音量 調郎系統。 [0005] 一種音量調節系統，用於接收一音頻輸入裝置輸出的音 頻訊號，對該音頻訊號進行調節後傳輸到一音頻輸出裝 置。該音量調節系統包括：一直流準位偏置電路、一控 制電路及一音量處理電路。該直流準位偏置電路用於將 輸入的交流音頻訊號施加直流偏置電流後得到一具有直 流成分的交流音頻訊號。該控制電路用於根據該音頻輸 入裝置輸出的音頻訊號強度超過一預定值時產生相應的 098144034 0982075369-0 表單編號A0101 第4頁/共21頁 201123935 控制訊號。該音量處理電路根據該控制訊號對該直流準 位偏置電路輸出的音頻訊號進行處理，使該音量處理電 路輸出的音頻訊號的音量在該音頻輸出裝置允許的音量 輸出範圍内。 [0006] 上述音量調節系統，在產生破音的情況下，藉由控制電 路來輸出一合適的增益量，對該音頻輸入裝置的左聲道 、右聲道輸出的音頻訊號進行增益處理，使該音量處理 電路輸出的音量在該音頻輸出裝置的音量範圍内，避免 了破音現象的產生。 【實施方式】 [0007] 下面將結合附圖，對本發明作進一步的詳細說明。 [0008] 為了對本發明的音量調節系統做進一步的說明，舉以下 實施方式並配合附圖進行詳細説明。 [0009] 請參閱圖1，本發明較佳實施方式提供的一種音量調節系 統100用於接收一音頻輸入裝置20輸入的音頻訊號，對該 音頻訊號進行調節後傳輸到一音頻輸出裝置30，從而實 現對該音頻輸出裝置30的音量的自動調節，避免該音頻 輸出裝置30輸出的音頻訊號產生破音的現象。具體地， 該音頻輸入裝置20輸出的音頻訊號可以為單聲道或多聲 道，本實施方式中，以兩聲道為例進行說明，即包括左 聲道（left channel, LC)輸出訊號及右聲道（right channel, RC)輸出訊號。 [0010] 該音量調節系統100包括一直流準位偏置電路12、一控制 電路14及一音量處理電路16。 098144034 表單編號A0101 第5頁/共21頁 0982075369-0 201123935 [0011] 該直流準位偏置電路12的輸入端與該音頻輸入裝置20相 連接，輸出端與該音量處理電路16相連接。一般地，該 音頻輸入裝置20輸入的音頻訊號為交流音頻訊號，該直 流準位偏置電路12用於將輸入的交流音頻訊號施加直流 偏置電壓後得到一具有直流成分的交流音頻訊號。 [0012] 該控制電路14的輸入端與該音頻輸入裝置20相連接，輸 出端與該音量處理電路16相連接。該控制電路14用於根 據該音頻輸入裝置20輸入的音頻訊號產生一控制訊號。 [0013] 該音量處理電路16包括一左聲道增益控制電路162與一右 聲道增益控制電路164，該音量處理電路16根據該控制訊 號對該直流準位偏置電路12輸出的音頻訊號進行處理， 使該音量處理電路16輸出的音頻訊號的音量在該音頻輸 出裝置30允許的音量輸出範圍内。該音量處理電路16的 輸出端與該音頻輸出裝置30相連接，使經過該音量處理 電路16的音頻訊號經過該音頻輸出裝置30輸出聲音。 [0014] 請結合圖2A、圖2B，該直流準位偏置電路12包括一第一 反向求和放大電路122及一第二反向求和放大電路124。 該第一反向求和放大電路122的輸入端與該音頻輸入裝置 20的左聲道輸出相連接，輸出端與該左聲道增益控制電 路162相連接。該第二反向求和放大電路124的輸入端與 該音頻輸入裝置20的右聲道輸出相連接，輸出端與該右 聲道增益控制電路164相連接。 [0015] 具體地，該第一反向求和放大電路122包括一第一放大器 U1、一第一電阻R1、一第二電阻R2及一第三電阻R3。該 098144034 表單編號A0101 第6頁/共21頁 201123935 [0016] Ο [0017] [0018] ❹ 第一反向求和放大電路122的輸入端1221與該音頻輸入裝 置2 0的左聲道輸出相連接。該第一放大器ΙΠ的正向輸入 端接地，負向輸入端藉由該第一電阻R1與該第一反向求 和放大電路122的輸入端相遘接，並藉由該第二電阻R2與 該第一放大器U1的輸出端相連接，另外還藉由該第三電 阻R3與該正電壓端U相連接。 該第二反向求和放大電路124的結構與該第一反向求和放 大電路122基本相同，不同之處在於，該第二反向求和放 大電路124的輸入端與該音頻輸入裝置20的右聲道輸出相 連接。本實施方式中，該第一放大器U1的正負電源端分 別施加+ 12V和-12V的電壓。該第一電阻R1、第二電阻R2 、第三電阻R3的阻值均為10ΚΩ。 該控制電路14包括一振幅偵測及放大電路142、一放電電 路144及一觸發電路146。 該振幅偵測及放大電路142用於偵測出該音頻輸入裝置20 輸入的音頻訊號的負電壓峰值，並將該負電壓峰值轉換 為正電壓峰值後輪出至該放電電路144。具體地，該振幅 偵測及放大電路142包括一第二放大器U2、一第一二極體 D1、一第二二極體D2及一第三二極體D3。該第一二極體 D1的陰極與該青頻輸入裝置20的左聲道輸出相連接，該 第二二極體D2的陰極與該音頻輸入裝置20的右聲道輸出 相連接。該第一二極體D1及該第二二極體D2的陽極均藉 由一第四電阻R4與該第二放大器U2的負向輸入端相連接 。該第二放大器U2的負向輸入端還藉由一第五電阻R5與 輸出端相連接，該第二放大器U2的正向輸入端接地，該 098144034 表單編號Α0101 第7頁/共21頁 0982075369-0 201123935 第三:極體D3的陽極與該放電電路144相連接。其中，該 ^ 體D1及第二二極體的在輸人正電㈣音頻訊號 处於、止狀態’即保證該振幅偵測及放大電路142只能 接收並藉由負電壓的音㈣號，以便之後訊號處理。該 第二二極體咖證輸出正電壓且可防止回流。本實施方 式中’該第二放大器U2的正負電源端分別施加+旧和_ 12V的電魔。第四電阻R4的阻值為則，該第五電阻R5 的阻值為12ΚΩ。 [0019]201123935 VI. Description of the Invention: [Technical Field] [0001] The present invention relates to a volume adjustment technique, and more particularly to a volume adjustment system. [Prior Art] [0002] At present, electronic devices such as mobile phones and portable music playback devices include an audio driving circuit for driving sound generating devices such as a slapphone and a headphone. Typically, the audio drive circuit includes a digital to analog converter and an amplifier. The digital-to-analog converter receives the digital audio signal and converts it into an analog signal. The amplifier amplifies the analog signal and provides it to the sound producing device to sound. [〇〇〇3] In actual applications, the sound output device such as the speaker or earphone saves the maximum output volume limit. If the maximum rounding volume limit is exceeded, a broken sound will occur. This kind of broken sound often causes problems for the user, and may damage some highly sensitive components. [Invention] [0004] In view of this, it is necessary to provide a volume adjustment that prevents breakage. Lang system. [0005] A volume adjustment system for receiving an audio signal output by an audio input device, adjusting the audio signal, and transmitting the audio signal to an audio output device. The volume adjustment system comprises: a constant current level bias circuit, a control circuit and a volume processing circuit. The DC level bias circuit is configured to apply a DC bias current to the input AC audio signal to obtain an AC audio signal having a DC component. The control circuit is configured to generate a corresponding 098144034 0982075369-0 according to the audio signal strength output by the audio input device exceeding a predetermined value. Form No. A0101 Page 4 of 21 201123935 Control signal. The volume processing circuit processes the audio signal output by the DC level biasing circuit according to the control signal, so that the volume of the audio signal output by the volume processing circuit is within the volume output range allowed by the audio output device. [0006] The above volume adjustment system generates a suitable amount of gain by the control circuit in the case of generating a broken sound, and performs gain processing on the audio signals output from the left channel and the right channel of the audio input device, so that The volume output by the volume processing circuit is within the volume range of the audio output device, thereby avoiding the occurrence of breakage. [Embodiment] The present invention will be further described in detail below with reference to the accompanying drawings. [0008] In order to further explain the volume adjustment system of the present invention, the following embodiments will be described in detail with reference to the accompanying drawings. Referring to FIG. 1 , a volume adjustment system 100 is provided for receiving an audio signal input by an audio input device 20 , and adjusting the audio signal to be transmitted to an audio output device 30 , thereby The automatic adjustment of the volume of the audio output device 30 is achieved to avoid the phenomenon that the audio signal output by the audio output device 30 is broken. Specifically, the audio signal output by the audio input device 20 may be mono or multi-channel. In this embodiment, the two channels are taken as an example, that is, the left channel (LC) output signal is included. Right channel (RC) output signal. [0010] The volume adjustment system 100 includes a DC level bias circuit 12, a control circuit 14, and a volume processing circuit 16. 098144034 Form No. A0101 Page 5 of 21 0982075369-0 201123935 [0011] The input of the DC level bias circuit 12 is connected to the audio input device 20, and the output is connected to the volume processing circuit 16. Generally, the audio signal input by the audio input device 20 is an AC audio signal, and the DC level bias circuit 12 is configured to apply a DC bias voltage to the input AC audio signal to obtain an AC audio signal having a DC component. [0012] The input of the control circuit 14 is connected to the audio input device 20, and the output is connected to the volume processing circuit 16. The control circuit 14 is operative to generate a control signal based on the audio signal input by the audio input device 20. The volume processing circuit 16 includes a left channel gain control circuit 162 and a right channel gain control circuit 164. The volume processing circuit 16 performs the audio signal output by the DC level offset circuit 12 according to the control signal. Processing, the volume of the audio signal output by the volume processing circuit 16 is within the volume output range allowed by the audio output device 30. The output of the volume processing circuit 16 is coupled to the audio output device 30 such that the audio signal passing through the volume processing circuit 16 outputs sound through the audio output device 30. 2A and 2B, the DC level bias circuit 12 includes a first reverse summing circuit 122 and a second reverse summing circuit 124. The input of the first inverse summing and amplifying circuit 122 is connected to the left channel output of the audio input device 20, and the output terminal is connected to the left channel gain control circuit 162. The input of the second inverse summing and amplifying circuit 124 is connected to the right channel output of the audio input device 20, and the output terminal is connected to the right channel gain control circuit 164. [0015] Specifically, the first reverse summing and amplifying circuit 122 includes a first amplifier U1, a first resistor R1, a second resistor R2, and a third resistor R3. The 098144034 Form No. A0101 Page 6 of 21 201123935 [0016] [0018] The input end 1221 of the first reverse summing and amplifying circuit 122 and the left channel output of the audio input device 20 connection. The forward input terminal of the first amplifier 接地 is grounded, and the negative input terminal is coupled to the input end of the first reverse summing and amplifying circuit 122 by the first resistor R1, and the second resistor R2 is coupled to The output of the first amplifier U1 is connected, and the third resistor R3 is connected to the positive voltage terminal U. The structure of the second reverse summing and amplifying circuit 124 is substantially the same as that of the first reverse summing and amplifying circuit 122, except that the input end of the second reverse summing and amplifying circuit 124 and the audio input device 20 The right channel output is connected. In this embodiment, the positive and negative power terminals of the first amplifier U1 are applied with voltages of +12V and -12V, respectively. The resistances of the first resistor R1, the second resistor R2, and the third resistor R3 are all 10 Ω. The control circuit 14 includes an amplitude detecting and amplifying circuit 142, a discharging circuit 144 and a trigger circuit 146. The amplitude detecting and amplifying circuit 142 is configured to detect a negative voltage peak of the audio signal input by the audio input device 20, and convert the negative voltage peak into a positive voltage peak and then output to the discharging circuit 144. Specifically, the amplitude detecting and amplifying circuit 142 includes a second amplifier U2, a first diode D1, a second diode D2, and a third diode D3. The cathode of the first diode D1 is connected to the left channel output of the blue frequency input device 20, and the cathode of the second diode D2 is connected to the right channel output of the audio input device 20. The anodes of the first diode D1 and the second diode D2 are connected to the negative input terminal of the second amplifier U2 via a fourth resistor R4. The negative input terminal of the second amplifier U2 is also connected to the output terminal through a fifth resistor R5, and the forward input terminal of the second amplifier U2 is grounded. The 098144034 form number Α0101 page 7 / 21 pages 0992075369- 0 201123935 Third: The anode of the polar body D3 is connected to the discharge circuit 144. Wherein, the body D1 and the second diode are in the positive and negative state of the input (4) audio signal, that is, the amplitude detection and amplification circuit 142 can only receive and receive the negative (4) number of the negative voltage. So that the signal can be processed later. The second diode package outputs a positive voltage and prevents backflow. In the present embodiment, the positive and negative power terminals of the second amplifier U2 are respectively applied with + old and -12V electric magic. The resistance of the fourth resistor R4 is then, and the resistance of the fifth resistor R5 is 12 ΚΩ. [0019]
該放電電路U4用於對該振幅_及放大電路142輸出的 正電壓峰值進，了分壓處理。具體地，該義電路包括 一第-電容C1及四條支路1第—電容C1的—端與該第 三二極體D3的陰極相連接，另—端接地。為簡便起見， 以下只具體描述了四條支路中其中一條、即第一支路 144a的具體電路結構。該第—支路U4a包括一輸入端 1441與一輸出端1442以及順序串聯在該輸入端1441與地 電勢之間的一第六電阻R6及—第七電阻R7。具體地，該 輸入端1441連接至振幅偵測及放大電路Μ〗中的該第三二 極體D3的陰極，該第六電阻r6與第七電阻R7的串接處構 成輸出端1442，連接至觸發電路146。該放電電路144的 其他各支路的結構與該第一支路144a基本相同，該四條 支路的不同之處在於，各支路中的第六電阻抓的阻值互 不相同。該第一電容C1用於積累電壓，以供該放電電路 144中的電阻分壓以及觸發該觸發電路146 ^本實施方式 中，該第一電容C1的電容量為22uF。該放電電路144的 四條支路中的第六電阻R6的阻值依次增大，分別為5. 9K 098144034 表單編號Α0101 第8頁/共21頁 0982075369-0 201123935 Ω、8·45ΚΩ、11.8ΚΩ 及 15.8ΚΩ。該放電電路 144 的 四條支路中的第七電阻R7的阻值均為10ΚΩ。 [0020]该觸發電路146用於根據經過該放電電路144的音頻訊號 的強度不同而觸發，產生驅動該音量處理電路16的相應 的控制訊號。該觸發電路包括結構相同的四條支路。 該觸發電路146的四條支路分別與該放電電路144的四條 支路對應連接。為簡便起見，以下只具體描述了四條支 路中的一條，即第一支路146a的具體電路結構。該第— ❹ 支路l46a包括一輸入端14料與·^輪电端1462、以及連接 在該輸入端1461與趣輪出端1462的一比較器A、一第八 電阻R8及一第一電容C2。該第—支路146a的輸入端1461 與該放電電路144的第一支路i44a的輸出端1442相連接 ，該比較器A的正向輸入端與該觸發電路146的第一支路 146a的輸入端1461相連接，負向輸入端與該正電壓端卩 相連接，該比較器A的負電墀端接地，該第八電阻以的_ 端與該比較器A的正電源端相連接，該第二電容C2的一端 〇 _，該第人電阻_另-端、該第二電容C2的另-端 及該比較器A的輸出端制連接至f第-支路14^的輸出 端。各支路中的比較器A均具有—觸發電壓值，從輸入端 1461輸入的音頻訊號的強度達到該觸發電壓值後該比較 器A則被觸發。‘其巾’該第二電容e2均起穩壓的作用。本 實施方式中，比較器a的正負電漏端分別施加+m和〇的 電壓。該第二電容C2的電容量為〇 lu卜該第八電阻R8 ㈣㈣4·7ΚΩ。本實施方以，該正電壓端U所接的電 壓為+ 3. 3V。 098144034 表單編號Α0101 0982075369-0 201123935 [0021] 該左聲道增益控制電路162根據該觸發電路146輸出的控 制訊號對該直流準位偏置電路12輸出的左聲道輸出的音 頻訊波進行增益處理。具體地’該左聲道增益控制電路 162包括一放大電路1621及一開關電路1622。 [0022] 該放大電路1621包括一輸入端1621a、一輸出端1621b以 及連接在該輸入端162 la與該輸出端162 lb之間的一第三 放大器U3、一第九電阻R9及一第十電阻R10。該放大電路 1621的輸入端1621a與該第一反向求和放大電路122的輸 出端1 222相連接。該放大電路1621的輸出端1621b與該 音頻輸出裝置3 0相連接。該第三放大器U 3的正向輸入端 接地，負向輸入端藉由該第九電阻R9與該放大電路1621 的輸入端1621a相連接，且藉由該第十電阻Ri〇與該第三 放大器U3的輸出端相連接。 [0023] 該開關電路1622包括四條支路，該開關電路1622的四條 支路分別與該觸發電路146的四條支路對應連接。為簡便 起見，以下亦只具體播述了四條支路中其中一條、即第 一支路1622a的具體電路結構。該第一支路1 622a包括一 輸入端1623、一輸出端1624以及連接在該輸入端1623與 該輸出端1624之間的一可控開關κ及一第十一電阻rii。 該第一支路1 622a的輸入端1 623與該觸發電路146a的對 應支路的輸出端1462相連接，輸出端1624與該第三放大 器U3的負向輸入端相連接《該可控開關〖的輸入端藉由該 第十一電阻R11與該放大電路1621的輸出端16211)相連接 ，輸出端與該第三放大器U3的負向輸入端相連接，控制 端連接至第一支路1 622a的輸出端1623相連接。該開關 098144034 表單編號A0101 第10頁/共21頁 0982075369-0 201123935 電路1 622的其他支路的結構與該開關電路1622的第一支 路1 622a基本相同，該開關電路1622各支路的不同之處 在於，各支路中的第十一電阻Rl 1的阻值可以相同也可以 不同。本實施方式中，第三放大器U3的正負電源端分別 施加+ 12V和-12V的電壓。第九電阻R9、第十電阻R10的 阻值均為10ΚΩ，該開關電路1622的四條支路中的第十一 電阻R11的阻值依次減小，分別為90ΚΩ、72ΚΩ、56ΚΩ 及42ΚΩ。 ^ [0024] 該右聲道增益控制電路164根據該觸發電路146輸出的控 制訊號對該直流準位偏置電路12輸出的右聲道輸出的音 頻訊號進行增益處理。具體地，該右聲道增益控制電路 164的結構與該左聲道增益控制電路162基本相同。不同 之處在於，該右聲道增益控制電路164中的放大電路1621 的輸入端與該第二反向求和放大電路124的輸出端相連接 〇 [0025] 在實際應用中，經過該左、右聲道增益控制電路162、 Ο 164後的訊號需要經過一可以濾除直流訊號的電容，將訊 號還原使之可以藉由該音頻輸出裝置30(如：喇叭）輸出 〇 [0026] 可以理解，該音頻輸入裝置20輸出的音頻訊號可以不分 為左聲道輸出及右聲道輸出，而係只輸出一路，對應音 頻輸入裝置20輸出的一路音頻訊號，該音量調節系統100 的直流準位偏置電路12只需包括一反向求和放大電路、 振幅偵測及放大電路142只需包括一連接至音頻輸入裝置 20的二極體、音量處理電路只需包括一聲道增益控制電 098144034 表單編號A0101 第Π頁/共21頁 0982075369-0 201123935 路。 [0027] 該音頻輸入裝置20的左聲道輸出及右聲道輸出分別輸出 一音頻訊號，該音頻訊號分別經過該直流準位偏置電路 12及該振幅偵測及放大電路142，經過該振幅偵測及放大 電路142及該放電電路144進行處理後若該觸發電路146 無法得到觸發，則說明該音頻訊號經過放大後不會產生 破音現象，該音頻訊號直接經過該左、右聲道增益控制 電路162、164内的放大電路1621輸出至該音頻輸出裝置 30輸出。否則，若該音頻訊號的強度超出一預定值時， 該振幅偵測及放大電路142偵測出音頻訊號的峰值電壓， 輸出至該第一電容C1，該放電電路144中的各支路對該第 一電容C1中積累的電壓進行分壓，該第一電容C1累積電 壓至一定數值後會觸發相應的觸發電路146的一條或多條 支路導通，使該一條或多條支路中的比較器A輸出高電平 ，從比較器A中輸出的高電平使相應的該左聲道增益電路 162及該右聲道增益電路164中的可控開關K導通，從而改 變加在該第三放大器U3中的負向輸入端及輸出端之間的 y 電阻值來降低該第三放大器U3的放大倍數，保證該左聲 道輸出、右聲道輸出進行增益處理後藉由該音頻輸出裝 置30輸出的音量不會出現破音的現象。本實施方式中， 經過該放電電路144的第一支路後該觸發電路146的第一 支路被觸發，則對應的比較器A輸出為高電平時，控制該 左、右聲道增益電路162、164的開關電路1 622的第一支 路1 622a中的可控開關K導通，音頻訊號輸出增益為90% 。依次類推，分別還可以達到80%、70%及60%三級增益 098144034 表單編號A0101 第12頁/共21頁 0982075369-0 201123935 [0028] [0029] G [0030] [0031] Ο [0032] [0033] [0034] 可以理解，音頻輸入裝置20的輸出可以為一聲道或多個 聲道’只要相應的改變該振幅偵測及放大電路142中的第 —極體D1或第二二極體D2的數量及音量處理電路μ中 的增益控制電路的數量即可實現。 可以理解’若想改變增益的級數以及每級的増益量則 可以藉由增加該放電電路144、該觸發電路146、該左聲 道增益電路162及該右聲道增益電路164中開關電路1622 的支路的數量以及每支路中充.的相應參數來實現。 . :. ... . 上述音量調節系統’在產生破音的情況下，藉由控制電 路來輸出一合適的增益量，對:該音頻輸入裝置的左聲道 輸出 '右聲道輸出的音頻訊號進行增益處理，使該音量 處理電路輸出的音量在該音頻輸出裝置的音量範圍内， 避免了破音現象的產生。 綜上所述，本發明確已符合—發明專利之要件，遂依法提 出專利申請。惟，以上該者僅為本發明之較佳實施方式 ’自不能以此限制本案之申請專利範圍。舉凡熟悉本案 技藝之人士援依本發明之精神所作之等效修飾或變化， 皆應涵蓋於以下申請專利範圍内。 【圖式簡單說明】 圖1為本發明較佳實施方式的音量調節系統的電路框圖。 圖2Α、圖2Β為圖1中的音量調節***的一種電路圖 【主要元件符號說明】 音量調節系統 100 098144034 表單編號Α0101 第13頁/共21頁 0982075369-0 100 201123935 [0035] 直流準位偏置電路 12 [0036] 第·—反向求和放大電路 122 [0037] 放大電路的輸入端 1221 [0038] 放大電路的輸出端 1222 [0039] 第二反向求和放大電路 124 [0040] 控制電路 14 [0041] 振幅偵測及放大電路 142 [0042] 放電電路 144 [0043] 放電電路的第一支路 144a [0044] 第一支路的輸入端 1441 [0045] 第一支路的輸出端 1442 [0046] 觸發電路 146 [0047] 觸發電路的第一支路 146a [0048] 觸發電路的第一支路的輸入端 1461 [0049] 觸發電路的第一支路的輸出端 1462 [0050] 音量處理電路 16 [0051] 左聲道增益控制電路 162 [0052] 放大電路 1621 [0053] 放大電路的輸入端 1621a 098144034 表單編號A0101 第14頁/共21頁 0982075369-0 201123935 [0054] 放大電路的輸出端 1621b [0055] 開關電路 1622 [0056] 開關電路的第一支路 1622a [0057] 開關電路的第一支路的輸入端 1623 [0058] 開關電路的第一支路的輸出端 1624 [0059] 右聲道增益控制電路 164 [0060] 音頻輸入裝置 20 [0061] 音頻輸出裝置 30 098144034 表單編號A0101The discharge circuit U4 is used to perform a voltage division process on the amplitude _ and the positive voltage peak output from the amplifier circuit 142. Specifically, the circuit includes a first capacitor C1 and four branches. The first terminal of the capacitor C1 is connected to the cathode of the third diode D3, and the other terminal is grounded. For the sake of brevity, only the specific circuit structure of one of the four branches, that is, the first branch 144a, will be specifically described below. The first branch U4a includes an input terminal 1441 and an output terminal 1442, and a sixth resistor R6 and a seventh resistor R7 sequentially connected in series between the input terminal 1441 and the ground potential. Specifically, the input terminal 1441 is connected to the cathode of the third diode D3 in the amplitude detecting and amplifying circuit, and the serial connection of the sixth resistor r6 and the seventh resistor R7 constitutes an output end 1442, which is connected to Trigger circuit 146. The other branches of the discharge circuit 144 have substantially the same structure as the first branch 144a, and the four branches are different in that the resistance values of the sixth resistors in the respective branches are different from each other. The first capacitor C1 is used to accumulate voltage for voltage division in the discharge circuit 144 and to trigger the trigger circuit 146. In the embodiment, the capacitance of the first capacitor C1 is 22 uF. The resistance of the sixth resistor R6 of the four branches of the discharge circuit 144 is sequentially increased, respectively. 5.KK 098144034 Form No. 1010101 Page 8 of 21 0982075369-0 201123935 Ω, 8·45ΚΩ, 11.8ΚΩ and 15.8 Κ Ω. The seventh resistor R7 of the four branches of the discharge circuit 144 has a resistance of 10 Ω. The trigger circuit 146 is configured to trigger according to the intensity of the audio signal passing through the discharge circuit 144 to generate a corresponding control signal for driving the volume processing circuit 16. The trigger circuit includes four branches of the same structure. The four branches of the flip-flop circuit 146 are respectively connected to the four branches of the discharge circuit 144. For the sake of brevity, only one of the four branches, that is, the specific circuit structure of the first branch 146a, will be specifically described below. The first ❹ branch l46a includes an input end 14 and a ^1 electric terminal 1462, and a comparator A, an eighth resistor R8 and a first capacitor connected to the input end 1461 and the interesting wheel end 1462. C2. The input end 1461 of the first branch 146a is coupled to the output 1442 of the first branch i44a of the discharge circuit 144. The forward input of the comparator A and the input of the first branch 146a of the trigger circuit 146 The terminal 1461 is connected, the negative input terminal is connected to the positive voltage terminal ,, the negative terminal of the comparator A is grounded, and the _ terminal of the eighth resistor is connected with the positive power terminal of the comparator A, the first One end of the two capacitor C2 〇 _, the first resistor _ other end, the other end of the second capacitor C2 and the output end of the comparator A are connected to the output end of the f-branch 14^. Comparator A in each branch has a trigger voltage value, and the comparator A is triggered after the intensity of the audio signal input from the input terminal 1461 reaches the trigger voltage value. The second capacitor e2 of 'the towel' acts as a voltage regulator. In the present embodiment, the positive and negative electric leakage terminals of the comparator a are applied with voltages of +m and 〇, respectively. The capacitance of the second capacitor C2 is 第八lu, the eighth resistor R8 (four) (four) 4·7 Κ Ω. In this embodiment, the voltage connected to the positive voltage terminal U is +3.3 V. 098144034 Form No. Α0101 0982075369-0 201123935 [0021] The left channel gain control circuit 162 performs gain processing on the left channel output audio signal output from the DC level bias circuit 12 according to the control signal outputted by the trigger circuit 146. . Specifically, the left channel gain control circuit 162 includes an amplifying circuit 1621 and a switching circuit 1622. [0022] The amplifying circuit 1621 includes an input terminal 1621a, an output terminal 1621b, and a third amplifier U3, a ninth resistor R9 and a tenth resistor connected between the input terminal 162la and the output terminal 162bb. R10. The input terminal 1621a of the amplifying circuit 1621 is connected to the output terminal 1 222 of the first reverse summing and amplifying circuit 122. The output terminal 1621b of the amplifying circuit 1621 is connected to the audio output device 30. The forward input terminal of the third amplifier U 3 is grounded, and the negative input terminal is connected to the input terminal 1621a of the amplifying circuit 1621 by the ninth resistor R9, and the tenth resistor Ri 〇 and the third amplifier The output of U3 is connected. [0023] The switch circuit 1622 includes four branches, and the four branches of the switch circuit 1622 are respectively connected to the four branches of the trigger circuit 146. For the sake of brevity, only the specific circuit structure of one of the four branches, the first branch 1622a, will be specifically described below. The first branch 1 622a includes an input terminal 1623, an output terminal 1624, and a controllable switch κ and an eleventh resistor rii connected between the input terminal 1623 and the output terminal 1624. The input end 1 623 of the first branch 1 622a is connected to the output end 1462 of the corresponding branch of the trigger circuit 146a, and the output end 1624 is connected to the negative input end of the third amplifier U3. The input end is connected to the output end 16211) of the amplifying circuit 1621 by the eleventh resistor R11, the output end is connected to the negative input end of the third amplifier U3, and the control end is connected to the first branch 1 622a The output terminals 1623 are connected. The switch 098144034 Form No. A0101 Page 10 / Total 21 page 0992075369-0 201123935 The structure of the other branches of Circuit 1 622 is substantially the same as the first branch 1 622a of the switch circuit 1622, the different branches of the switch circuit 1622 The resistance of the eleventh resistor R11 in each branch may be the same or different. In the present embodiment, the positive and negative power terminals of the third amplifier U3 are applied with voltages of +12V and -12V, respectively. The resistance values of the ninth resistor R9 and the tenth resistor R10 are both 10 Ω, and the resistance of the eleventh resistor R11 of the four branches of the switch circuit 1622 is sequentially decreased, which are 90 Κ Ω, 72 Κ Ω, 56 Κ Ω, and 42 Κ Ω, respectively. [0024] The right channel gain control circuit 164 performs gain processing on the audio signal output from the right channel output by the DC level bias circuit 12 according to the control signal outputted by the trigger circuit 146. Specifically, the structure of the right channel gain control circuit 164 is substantially the same as the left channel gain control circuit 162. The difference is that the input end of the amplifying circuit 1621 in the right channel gain control circuit 164 is connected to the output end of the second inverse summing amplifying circuit 124. [0025] In practical applications, after the left, The signals after the right channel gain control circuit 162 and Ο 164 need to pass through a capacitor that can filter out the DC signal, and the signal is restored so that it can be outputted by the audio output device 30 (eg, a speaker) [0026]. The audio signal output by the audio input device 20 can be divided into a left channel output and a right channel output, and only one channel is output, corresponding to an audio signal output by the audio input device 20, and the DC level of the volume adjustment system 100 is biased. The circuit 12 only needs to include a reverse summing and amplifying circuit. The amplitude detecting and amplifying circuit 142 only needs to include a diode connected to the audio input device 20. The volume processing circuit only needs to include a channel gain control circuit 098144034. No. A0101 Page/Total 21 page 0982075369-0 201123935 Road. [0027] The left channel output and the right channel output of the audio input device 20 respectively output an audio signal, and the audio signal passes through the DC level bias circuit 12 and the amplitude detecting and amplifying circuit 142, respectively, through the amplitude. After the detection and amplification circuit 142 and the discharge circuit 144 are processed, if the trigger circuit 146 cannot be triggered, it indicates that the audio signal is amplified and does not generate a sound break phenomenon, and the audio signal directly passes through the left and right channel gains. The amplifying circuit 1621 in the control circuits 162, 164 outputs the output to the audio output device 30. Otherwise, if the intensity of the audio signal exceeds a predetermined value, the amplitude detecting and amplifying circuit 142 detects the peak voltage of the audio signal, and outputs the peak voltage to the first capacitor C1, and the branches in the discharging circuit 144 The voltage accumulated in the first capacitor C1 is divided, and the accumulated voltage of the first capacitor C1 reaches a certain value, which triggers one or more branches of the corresponding trigger circuit 146 to be turned on, so that the one or more branches are compared. The controller A outputs a high level, and the high level outputted from the comparator A causes the corresponding controllable switch K in the left channel gain circuit 162 and the right channel gain circuit 164 to be turned on, thereby changing the third The y resistance value between the negative input terminal and the output terminal of the amplifier U3 reduces the amplification factor of the third amplifier U3, and ensures that the left channel output and the right channel output are subjected to gain processing by the audio output device 30. The output volume does not appear to be broken. In this embodiment, after the first branch of the discharge circuit 144 is triggered, the first branch of the trigger circuit 146 is triggered, and when the corresponding comparator A output is high, the left and right channel gain circuits 162 are controlled. The controllable switch K in the first branch 1 622a of the switching circuit 1 622 of 164 is turned on, and the audio signal output gain is 90%. By analogy, 80%, 70%, and 60% third-order gains can also be achieved respectively. 098144034 Form No. A0101 Page 12/Total 21 Page 0982075369-0 201123935 [0028] [0029] [0032] [0032] [0034] It can be understood that the output of the audio input device 20 can be one channel or multiple channels' as long as the first pole D1 or the second pole in the amplitude detecting and amplifying circuit 142 is correspondingly changed. The number of the bodies D2 and the number of gain control circuits in the volume processing circuit μ can be realized. It can be understood that if the number of stages of the gain and the benefit amount of each stage are changed, the discharge circuit 144, the trigger circuit 146, the left channel gain circuit 162, and the switch circuit 1622 of the right channel gain circuit 164 can be increased. The number of branches and the corresponding parameters of each branch are implemented. . . . . The above volume adjustment system 'outputs a suitable amount of gain by the control circuit in the case of generating a broken sound. Pair: the left channel of the audio input device outputs the audio of the right channel output The signal is subjected to gain processing so that the volume output by the volume processing circuit is within the volume range of the audio output device, thereby avoiding the occurrence of breakage. In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above is only a preferred embodiment of the present invention, and the scope of the patent application of the present invention is not limited thereto. Equivalent modifications or variations made by those skilled in the art to the spirit of the invention are intended to be included within the scope of the following claims. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a circuit block diagram of a volume adjustment system in accordance with a preferred embodiment of the present invention. Figure 2Α, Figure 2Β is a circuit diagram of the volume adjustment system of Figure 1. [Main component symbol description] Volume adjustment system 100 098144034 Form number Α 0101 Page 13 / 21 page 0982075369-0 100 201123935 [0035] DC level offset Circuit 12 [0036] Inverting and amplifying circuit 122 [0037] Amplifying circuit input terminal 1221 [0038] Amplifying circuit output terminal 1222 [0039] Second reverse summing and amplifying circuit 124 [0040] Control circuit [0041] Amplitude detection and amplification circuit 142 [0042] Discharge circuit 144 [0043] First branch 144a of the discharge circuit [0044] Input end 1441 of the first branch [0045] Output end 1442 of the first branch Trigger circuit 146 [0047] First branch 146a of the trigger circuit [0048] Input 1461 of the first branch of the trigger circuit [0049] Output 1462 of the first branch of the trigger circuit [0050] Volume processing Circuit 16 [0051] Left Channel Gain Control Circuit 162 [0052] Amplifier Circuit 1621 [0053] Amplifier Circuit Input 1621a 098144034 Form Number A0101 Page 14 of 21 Page 2092075369-0 201123935 [0054] Amplifier Circuit Loss Terminal 1621b [0055] Switching Circuit 1622 [0056] First Branch 1622a of Switching Circuit [0057] Input 1623 of First Branch of Switching Circuit [0058] Output 1624 of First Branch of Switching Circuit [0059] Right channel gain control circuit 164 [0060] Audio input device 20 [0061] Audio output device 30 098144034 Form number A0101
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