TWI720676B

TWI720676B - Over temperature compensation control circuit

Info

Publication number: TWI720676B
Application number: TW108140027A
Authority: TW
Inventors: 林政毅; 闕弘文; 陳俊志
Original assignee: 台達電子工業股份有限公司
Priority date: 2019-11-05
Filing date: 2019-11-05
Publication date: 2021-03-01
Also published as: TW202119736A

Abstract

An over temperature compensation control circuit is coupled to a conversion unit, and the over temperature compensation control circuit includes a detection circuit, a temperature control resistor and a comparison unit. The detection circuit provides a current signal responsive to an input voltage according to a voltage signal responsive to the input voltage. The temperature control resistor generates a temperature control voltage according to the current signal, and the comparison unit compares the temperature control voltage with a reference voltage to generate a control signal. The control signal represents whether a temperature of the conversion unit reaches an over temperature protection point.

Description

過溫度補償控制電路 Over temperature compensation control circuit

本發明係有關一種過溫度補償控制電路，尤指一種動態的調整過溫度保護點的過溫度補償控制電路。 The invention relates to an over-temperature compensation control circuit, in particular to an over-temperature compensation control circuit that dynamically adjusts an over-temperature protection point.

為了確保人身安全、財產及環境等不受傷害和損失，針對電子產品在出廠時，通常會訂定產品的安全規範。其中，為避免電子產品的溫度過高而造成人身安全、財產及環境的損失，因此針對電子產品在運作時的溫度，通常具有比較嚴苛的安全規範。 In order to ensure that personal safety, property and the environment are not harmed and lost, product safety regulations are usually set for electronic products when they leave the factory. Among them, in order to avoid the loss of personal safety, property and environment caused by the excessively high temperature of electronic products, there are usually stricter safety regulations for the temperature of electronic products during operation.

由於未來安全規範的需求，系統/裝置無論輸入電壓的高低，系統/裝置的過溫度保護點必需要小於87℃。但是輸入電壓的高低通常會影響輸入電流的大小，而輸入電流的大小又影響到系統/裝置溫度的變化。因此，舊有的過溫度保護設計，在輸入電壓高低的影響下，會造成過溫度保護點的偏移而失去保護作用。 Due to the requirements of future safety regulations, regardless of the input voltage of the system/device, the over-temperature protection point of the system/device must be less than 87°C. However, the input voltage usually affects the input current, and the input current affects the temperature of the system/device. Therefore, the old over-temperature protection design will cause the over-temperature protection point to shift and lose its protection under the influence of the input voltage.

因此，如何設計出一種過溫度補償控制電路，提供過溫度保護點依不同的輸入電壓來調整，使得輸入無論是低壓或是高壓，皆能使系統/裝置到達過溫度保護點時，系統/裝置能夠正常地觸發而啟動過溫度保護，乃為本案發明人所欲行研究的重要課題。 Therefore, how to design an over-temperature compensation control circuit that provides over-temperature protection points that can be adjusted according to different input voltages, so that whether the input is low-voltage or high-voltage, it can enable the system/device When the over-temperature protection point is reached, the system/device can normally trigger to start the over-temperature protection, which is an important subject that the inventor intends to study.

為了解決上述問題，本發明係提供一種過溫度補償控制電路，以克服習知技術的問題。因此，本發明之過溫度補償控制電路耦接轉換單元，過溫度補償控制電路包括：偵測電路，耦接轉換單元，用以根據響應於提供給轉換單元的輸入電壓的電壓訊號而提供響應於輸入電壓的電流訊號。溫控電阻，耦接偵測電路，用以根據電流訊號產生溫控電壓。及比較單元，耦接溫控電阻，用以比較溫控電壓與參考電壓而產生控制訊號。其中，控制訊號代表轉換單元的溫度是否達到過溫度保護點。 In order to solve the above-mentioned problems, the present invention provides an over-temperature compensation control circuit to overcome the problems of the conventional technology. Therefore, the over-temperature compensation control circuit of the present invention is coupled to the conversion unit, and the over-temperature compensation control circuit includes: a detection circuit coupled to the conversion unit for providing a response based on a voltage signal in response to the input voltage provided to the conversion unit The current signal of the input voltage. The temperature control resistor is coupled to the detection circuit to generate a temperature control voltage according to the current signal. And the comparison unit, coupled to the temperature control resistor, for comparing the temperature control voltage with the reference voltage to generate a control signal. Among them, the control signal represents whether the temperature of the conversion unit reaches the over-temperature protection point.

為了解決上述問題，本發明係提供一種過溫度補償控制電路，以克服習知技術的問題。因此，本發明過溫度補償控制電路耦接轉換單元，過溫度補償控制電路包括：偵測電路，耦接轉換單元，用以根據響應輸入電壓的電壓訊號而提供響應輸入電壓的參考電壓。溫控電阻，耦接比較單元，用以根據電流訊號產生溫控電壓。及比較單元，耦接偵測電路，用以比較溫控電壓與參考電壓而產生控制訊號。其中，控制訊號代表轉換單元的溫度是否達到過溫度保護點。 In order to solve the above-mentioned problems, the present invention provides an over-temperature compensation control circuit to overcome the problems of the conventional technology. Therefore, the over-temperature compensation control circuit of the present invention is coupled to the conversion unit. The over-temperature compensation control circuit includes a detection circuit coupled to the conversion unit for providing a reference voltage responsive to the input voltage according to a voltage signal responsive to the input voltage. The temperature control resistor is coupled to the comparison unit for generating a temperature control voltage according to the current signal. And the comparison unit, coupled to the detection circuit, for comparing the temperature control voltage with the reference voltage to generate a control signal. Among them, the control signal represents whether the temperature of the conversion unit reaches the over-temperature protection point.

為了能更進一步瞭解本發明為達成預定目的所採取之技術、手段及功效，請參閱以下有關本發明之詳細說明與附圖，相信本發明之目的、特徵與特點，當可由此得一深入且具體之瞭解，然而所附圖式僅提供參考與說明用，並非用來對本發明加以限制者。 In order to have a better understanding of the technology, means and effects adopted by the present invention to achieve the intended purpose, please refer to the following detailed description and drawings of the present invention. I believe that the purpose, features and characteristics of the present invention can be obtained from this in depth and For specific understanding, however, the accompanying drawings are only provided for reference and illustration, and are not intended to limit the present invention.

100:轉換單元 100: conversion unit

10:整流單元 10: Rectifier unit

12:變壓器 12: Transformer

14:切換單元 14: Switching unit

16:輸出電路 16: output circuit

18:控制器 18: Controller

200:負載 200: load

300、300’:過溫度補償控制電路 300, 300’: Over temperature compensation control circuit

30、30’:偵測電路 30, 30’: Detection circuit

302、302’:電壓偵測電路 302, 302’: Voltage detection circuit

302A:輔助感應繞組 302A: auxiliary induction winding

302B:分壓電路 302B: Voltage divider circuit

R1:第一電阻 R1: first resistance

R2:第二電阻 R2: second resistor

304:放大電路 304: Amplifying circuit

D:二極體 D: Diode

(R3、R4):第一分壓電路 (R3, R4): The first voltage divider circuit

Vs:電壓源 Vs: voltage source

(R5、R6):回授迴路 (R5, R6): feedback loop

OP:放大器 OP: Amplifier

OUT:輸出端 OUT: output terminal

(+):正端 (+): Positive end

(-):負端 (-): Negative end

306:電流鏡電路 306: Current Mirror Circuit

306A:電流產生電路 306A: Current generating circuit

306B:電流鏡單元 306B: Current mirror unit

308:比較電路 308: comparison circuit

308A:第一比較單元 308A: The first comparison unit

308B:第二比較單元 308B: The second comparison unit

310:電壓選擇電路 310: Voltage selection circuit

Q1:第一開關 Q1: The first switch

Q2:第二開關 Q2: The second switch

32:溫控電阻 32: Temperature control resistance

34:比較單元 34: Comparison unit

Vin:輸入電壓 Vin: input voltage

Vo:輸出電壓 Vo: output voltage

Vd:直流電壓 Vd: DC voltage

Va:輔助電壓 Va: auxiliary voltage

Vc:溫控電壓 Vc: temperature control voltage

Vr:參考電壓 Vr: Reference voltage

Vr1:第一參考電壓 Vr1: the first reference voltage

Vr2:第二參考電壓 Vr2: second reference voltage

Vt:閥值電壓 Vt: Threshold voltage

Sv:電壓訊號 Sv: Voltage signal

Sa:電壓調整訊號 Sa: Voltage adjustment signal

Si:電流訊號 Si: current signal

Sr:電流調整訊號 Sr: Current adjustment signal

Sc:控制訊號 Sc: control signal

Sd:驅動訊號 Sd: drive signal

Sd1:第一驅動訊號 Sd1: The first drive signal

Sd2:第二驅動訊號 Sd2: second drive signal

A、B:過溫度保護點曲線 A, B: Over temperature protection point curve

X:轉折點 X: turning point

圖1為本發明具有過溫度補償控制電路之轉換單元電路方塊示意圖；圖2A為本發明過溫度補償控制電路第一實施例之電路方塊示意圖；圖2B為本發明過溫度補償控制電路第一實施例的偵測電路之細部電路示意圖；圖2C為本發明第一實施例的輸入電壓、電流訊號及溫度波形圖；圖3A為本發明過溫度補償控制電路第二實施例之電路方塊示意圖；圖3B為本發明過溫度補償控制電路第一實施例的偵測電路之細部電路示意圖；及圖3C為本發明第二實施例的輸入電壓、電流訊號及溫度波形圖。 Fig. 1 is a circuit block diagram of a conversion unit with an over-temperature compensation control circuit of the present invention; Fig. 2A is a circuit block diagram of the first embodiment of the over-temperature compensation control circuit of the present invention; Fig. 2B is a first implementation of the over-temperature compensation control circuit of the present invention Figure 2C is the input voltage, current signal and temperature waveform diagram of the first embodiment of the present invention; Figure 3A is the circuit block diagram of the second embodiment of the temperature compensation control circuit of the present invention; 3B is a detailed circuit diagram of the detection circuit of the first embodiment of the temperature compensation control circuit of the present invention; and FIG. 3C is the input voltage, current signal, and temperature waveform diagram of the second embodiment of the present invention.

茲有關本發明之技術內容及詳細說明，配合圖式說明如下：請參閱圖1為本發明具有過溫度補償控制電路之轉換單元電路方塊示意圖。轉換單元100接收輸入電壓Vin且將輸入電壓Vin轉換為輸出電壓Vo，且轉換單元100包括整流單元10、變壓器12、切換單元14、輸出電路16及控制器18。變壓器12的初級側耦接整流單元10與切換單元14，且變壓器12的次級側耦接輸出電路16。控制器18控制切換單元14與輸出電路16，使轉換單元 100可將輸入電壓Vin轉換為輸出電壓Vo。具體而言，整流單元10將輸入電壓Vin整流為直流電壓Vd，且直流電壓Vd通過切換單元14的切換與變壓器12耦合至輸出電路16，再經輸出電路16整流後提供輸出電壓Vo至負載200。過溫度補償控制電路300耦接轉換單元100，且根據輸入電壓Vin的大小設定過溫度保護點。其中，過溫度補償控制電路300可以設於變壓器12的初級側，用以偵測初級側的環境溫度，例如耦接變壓器12的初級側、整流單元10或是輸入電壓Vin(以虛線表示)。當轉換單元100運作時的溫度到達過溫度保護點時，過溫度補償控制電路300提供過溫度保護，以避免轉換單元100溫度過高而損壞。其中，轉換單元100可以為電子設備或系統/裝置內部的電源供應裝置，且轉換單元100可以為具有隔離變壓器的切換式轉換器。 The technical content and detailed description of the present invention are described as follows in conjunction with the drawings: Please refer to FIG. 1 for a block diagram of a conversion unit circuit with an over-temperature compensation control circuit of the present invention. The conversion unit 100 receives the input voltage Vin and converts the input voltage Vin into an output voltage Vo, and the conversion unit 100 includes a rectifier unit 10, a transformer 12, a switching unit 14, an output circuit 16 and a controller 18. The primary side of the transformer 12 is coupled to the rectifying unit 10 and the switching unit 14, and the secondary side of the transformer 12 is coupled to the output circuit 16. The controller 18 controls the switching unit 14 and the output circuit 16 so that the switching unit 100 can convert the input voltage Vin to the output voltage Vo. Specifically, the rectifying unit 10 rectifies the input voltage Vin to a DC voltage Vd, and the DC voltage Vd is coupled to the output circuit 16 through the switching of the switching unit 14 and the transformer 12, and then rectified by the output circuit 16 to provide the output voltage Vo to the load 200 . The over-temperature compensation control circuit 300 is coupled to the conversion unit 100 and sets an over-temperature protection point according to the magnitude of the input voltage Vin. The over-temperature compensation control circuit 300 can be provided on the primary side of the transformer 12 to detect the ambient temperature of the primary side, such as coupled to the primary side of the transformer 12, the rectifier unit 10, or the input voltage Vin (indicated by dashed lines). When the operating temperature of the conversion unit 100 reaches the over-temperature protection point, the over-temperature compensation control circuit 300 provides over-temperature protection to prevent the conversion unit 100 from being damaged due to excessive temperature. Wherein, the conversion unit 100 may be a power supply device inside an electronic device or a system/device, and the conversion unit 100 may be a switching converter with an isolation transformer.

具體而言，由於現今世界各國的公用市電的電壓值不盡相同，因此轉換單元100為了可一機適用世界各國，大多轉換單元100接設計為可接受寬電壓值的輸入電壓Vin(例如但不限於交流90V~264V)。但是由於在輸出功率相同的情況下，當輸入電壓Vin較低時(交流90V)，其輸入電流會較大會使得變壓器12的初級側溫度較高，且當輸入電壓Vin較高時(交流264V)，其輸入電流會較小會使得變壓器12的初級側溫度較低。但是，無論輸入電壓Vin高或低，變壓器12的次級側電流相同，溫度也是相近的，換言之，當次級側電流大到過溫情況發生時，變壓器12的初級側卻有可能因高的輸入電壓使得的輸入電流小而導致初級側的溫度仍未過過溫保護點。一般來說，溫控電阻是設在初級側，因此在次級側已發生過溫情況時，若是過溫度保護點設為定值時(例如，流經溫控電阻的電流為定值，其過溫判斷僅藉由溫控電阻的電阻值變化)，輸入電流較大可容易使轉換單元100的溫度容易碰觸到過溫度保護點，但是在相同情況下且輸入電流較小時，轉換單元100的初級側溫度較低使得溫控電阻仍在安全範圍而不容易碰觸到過溫度保護點。上述狀況會造成在輸入電流較小的情況，雖然轉換單元100整體溫度已經超過過溫度保護點，但是設於變壓器12初級側的過溫度補償控制電路300仍然未到達過溫度保護點而未觸發過溫度保護。因此本發明之主要目的及功效在於提供轉換單元100動態的過溫度保護點，使得無論輸入電壓Vin的大小為何，過溫度補償控制電路300皆能正確地觸發而提供過溫度保護。 Specifically, since the voltage values of public utility power in various countries in the world today are not the same, so in order to be able to adapt the conversion unit 100 to all countries in the world, most of the conversion units 100 are designed to accept an input voltage Vin of a wide voltage value (for example, but not Limited to AC 90V~264V). However, due to the same output power, when the input voltage Vin is low (AC 90V), the input current will be large, which will make the temperature of the primary side of the transformer 12 high, and when the input voltage Vin is high (AC 264V) , The input current will be smaller, which will make the primary side temperature of the transformer 12 lower. However, no matter the input voltage Vin is high or low, the secondary side current of the transformer 12 is the same, and the temperature is similar. In other words, when the secondary side current is so large that an over-temperature situation occurs, the primary side of the transformer 12 may be high. The input current caused by the input voltage is small and the temperature of the primary side has not yet exceeded the over-temperature protection point. Generally speaking, the temperature control resistor is set on the primary side, so when an over-temperature situation has occurred on the secondary side, if the over-temperature protection point is set to a fixed value (for example, the current flowing through the temperature control resistor is a fixed value, which The over-temperature judgment only depends on the change of the resistance value of the temperature-controlled resistor). A large input current can easily make the temperature of the conversion unit 100 easily touch the over-temperature protection point. However, under the same conditions and the input current is small, the conversion unit The low temperature of the primary side of 100 makes the temperature control resistor still in the safe range and it is not easy to touch the over-temperature protection point. The above situation will cause the input current to be small, although The overall temperature of the conversion unit 100 has exceeded the over-temperature protection point, but the over-temperature compensation control circuit 300 provided on the primary side of the transformer 12 still has not reached the over-temperature protection point and the over-temperature protection has not been triggered. Therefore, the main purpose and effect of the present invention is to provide a dynamic over-temperature protection point of the conversion unit 100, so that regardless of the magnitude of the input voltage Vin, the over-temperature compensation control circuit 300 can be triggered correctly to provide over-temperature protection.

值得一提，於本發明之一實施例中，若是過溫度補償控制電路300設於變壓器12的次級側以偵測次級側的環境溫度時，由於次級側的訊號傳輸回控制器18時，還必須經過隔離的耦合單元傳輸，因此會增加耦合單元的成本而導致增加整體電路的成本。因此本發明之過溫度補償控制電路300設置於變壓器12的初級側，可達成節省電路成本之功效。 It is worth mentioning that in one embodiment of the present invention, if the over-temperature compensation control circuit 300 is provided on the secondary side of the transformer 12 to detect the ambient temperature on the secondary side, the signal from the secondary side is transmitted back to the controller 18 At the same time, it must be transmitted through an isolated coupling unit, which will increase the cost of the coupling unit and result in an increase in the cost of the overall circuit. Therefore, the over-temperature compensation control circuit 300 of the present invention is arranged on the primary side of the transformer 12, which can achieve the effect of saving circuit cost.

請參閱圖2A為本發明過溫度補償控制電路第一實施例之電路方塊示意圖，復配合參閱圖1。過溫度補償控制電路300包括偵測電路30、溫控電阻32及比較單元34，且溫控電阻32耦接偵測電路30與比較單元34。偵測電路30耦接變壓器12的初級側，且根據響應輸入電壓Vin的電壓訊號Sv而提供響應輸入電壓Vin的電流訊號Si至溫控電阻32。溫控電阻32可以為負溫度係數的熱敏電阻，即當環境溫度越高時溫控電阻32的電阻值越小，當環境溫度越低時溫控電阻32的電阻值越大。當電流訊號Si流過溫控電阻32時，在溫控電阻32上產生溫控電壓Vc，且溫控電壓Vc響應電流訊號Si與溫控電阻32的大小。比較單元34比較溫控電壓Vc與參考電壓Vr，且根據比較結果而提供控制訊號Sc，控制訊號Sc的數值代表轉換單元100(變壓器12初級側)的溫度是否達到過溫度保護點。在一實施例中，控制訊號Sc為邏輯準位訊號。當參考電壓Vr大於或等於溫控電壓Vc時，控制訊號Sc為高邏輯準位訊號，此時代表發生過溫情況，而當參考電壓Vr小於溫控電壓Vc時，控制訊號Sc為低邏輯準位訊號，此時代表沒發生過溫情況。 Please refer to FIG. 2A which is a circuit block diagram of the first embodiment of the over-temperature compensation control circuit of the present invention. The over-temperature compensation control circuit 300 includes a detection circuit 30, a temperature control resistor 32 and a comparison unit 34, and the temperature control resistor 32 is coupled to the detection circuit 30 and the comparison unit 34. The detection circuit 30 is coupled to the primary side of the transformer 12 and provides a current signal Si responsive to the input voltage Vin to the temperature control resistor 32 according to the voltage signal Sv responsive to the input voltage Vin. The temperature control resistor 32 may be a thermistor with a negative temperature coefficient, that is, when the ambient temperature is higher, the resistance value of the temperature control resistor 32 is smaller, and when the ambient temperature is lower, the resistance value of the temperature control resistor 32 is larger. When the current signal Si flows through the temperature control resistor 32, a temperature control voltage Vc is generated on the temperature control resistor 32, and the temperature control voltage Vc responds to the size of the current signal Si and the temperature control resistor 32. The comparison unit 34 compares the temperature control voltage Vc with the reference voltage Vr, and provides a control signal Sc according to the comparison result. The value of the control signal Sc represents whether the temperature of the conversion unit 100 (primary side of the transformer 12) reaches the over-temperature protection point. In one embodiment, the control signal Sc is a logic level signal. When the reference voltage Vr is greater than or equal to the temperature control voltage Vc, the control signal Sc is a high logic level signal, which represents an over-temperature condition, and when the reference voltage Vr is less than the temperature control voltage Vc, the control signal Sc is a low logic level signal Bit signal, at this time, it means that no over-temperature has occurred.

簡單來說，本實施例的偵測電路30可根據輸入電壓Vin動態地調整流經溫控電阻32的電流訊號Si的大小，進而動態調整過溫保護點。具體來說，當參考電壓Vr大於溫控電壓Vc(環境溫度越高，溫控電阻32電阻值越小，在相同的電流訊號Si下溫控電壓Vc越小)時，意味著此時過溫情況已發生，因此過溫補償控制電路300輸出高邏輯準位的控制訊號Sc告知控制器18以進行保護機制。另外，在相同環境溫度的情況下(例如環境溫度為過溫點之溫度)，偵測單元30會根據輸入電壓Vin的大小對應調整其輸出的電流訊號Si值，例如當輸入電壓Vin越大，對應降低電流訊號Si的值，以減少溫控電壓Vc使其小於參考電壓Vr並觸發過溫保護，藉此避免當過溫情況已經發生時，設於初級側的溫控電阻32因輸入電壓Vin太大而輸入電流太小使得初級側溫度並未達到過溫點，造成其電阻值仍在安全範圍內，使得溫控電壓Vc仍大於參考電壓Vr的情況。在一實施例中，控制器18耦接比較單元34，且根據控制訊號Sc判斷轉換單元100的溫度是否達到該過溫度保護點，使轉換單元100可正確地啟動過溫度保護。 To put it simply, the detection circuit 30 of this embodiment can dynamically adjust the size of the current signal Si flowing through the temperature control resistor 32 according to the input voltage Vin, thereby dynamically adjusting the over-temperature protection point. Specifically, when the reference voltage Vr is greater than the temperature control voltage Vc (the higher the ambient temperature, the smaller the resistance value of the temperature control resistor 32, and the lower the temperature control voltage Vc under the same current signal Si), it means that the temperature is over-temperature at this time. The situation has occurred, so the over-temperature compensation control circuit 300 outputs a high logic level control signal Sc to inform the controller 18 to implement a protection mechanism. In addition, under the same ambient temperature (for example, the ambient temperature is the temperature of the over-temperature point), the detection unit 30 will correspondingly adjust the value of the output current signal Si according to the magnitude of the input voltage Vin. For example, when the input voltage Vin is greater, Correspondingly reduce the value of the current signal Si to reduce the temperature control voltage Vc to be less than the reference voltage Vr and trigger the over-temperature protection, thereby avoiding the temperature control resistor 32 set on the primary side due to the input voltage Vin when the over-temperature situation has occurred. If the input current is too large and the input current is too small, the temperature of the primary side does not reach the over-temperature point, and the resistance value is still within a safe range, so that the temperature control voltage Vc is still greater than the reference voltage Vr. In one embodiment, the controller 18 is coupled to the comparison unit 34, and determines whether the temperature of the conversion unit 100 reaches the over-temperature protection point according to the control signal Sc, so that the conversion unit 100 can correctly activate the over-temperature protection.

控制器18至少具有兩種過溫度保護的方式，其中之一為，控制器18設定溫度磁滯區間，且溫度磁滯區間包括過溫度保護點與低溫度復歸點。當控制器18根據控制訊號Sc得知轉換單元100的溫度達到過溫度保護點(例如100℃)時，控制器18關閉轉換單元100。意即，控制器18直接或間接地控制切換單元14與輸出電路16停止運作，使轉換單元100不再將輸入電壓Vin轉換為輸出電壓Vo。然後，待轉換單元100的溫度下降至低溫度復歸點(例如70℃)時，控制器18再復歸轉換單元100，使轉換單元100再開始將輸入電壓Vin轉換為輸出電壓Vo。藉此，避免溫度恰巧位於過溫度保護點附近，而使轉換單元100反覆且頻繁地控啟動/關閉而使轉換單元100喪失運作穩定性之功效。 The controller 18 has at least two over-temperature protection methods, one of which is that the controller 18 sets a temperature hysteresis interval, and the temperature hysteresis interval includes an over-temperature protection point and a low-temperature reset point. When the controller 18 knows that the temperature of the conversion unit 100 reaches the over-temperature protection point (for example, 100° C.) according to the control signal Sc, the controller 18 turns off the conversion unit 100. That is, the controller 18 directly or indirectly controls the switching unit 14 and the output circuit 16 to stop operating, so that the conversion unit 100 no longer converts the input voltage Vin to the output voltage Vo. Then, when the temperature of the conversion unit 100 drops to a low temperature reset point (for example, 70° C.), the controller 18 resets the conversion unit 100 so that the conversion unit 100 starts to convert the input voltage Vin to the output voltage Vo. In this way, it is avoided that the temperature happens to be near the over-temperature protection point, and the conversion unit 100 is repeatedly and frequently controlled to be turned on/off, and the conversion unit 100 loses the function of operating stability.

另外一種過溫度保護的方式為，控制器18鎖定轉換單元100。當控制器18根據控制訊號Sc得知轉換單元100的溫度達到過溫度保護點時，控制器18關閉並鎖定轉換單元100。此時，需要將輸入電壓Vin移除再重新供電，才可解除過溫度保護的鎖定，使轉換單元100重新回復而重新將輸入電壓Vin轉換為輸出電壓Vo。值得一提，於本發明之一實施例中，控制器18的過溫度保護方式可因應轉換單元100工作環境而設計，因此其過溫度保護方式並不限定僅有上述兩種保護方式。 Another way of over-temperature protection is that the controller 18 locks the conversion unit 100. When the controller 18 knows that the temperature of the conversion unit 100 reaches the over-temperature protection point according to the control signal Sc, it controls The switch 18 closes and locks the conversion unit 100. At this time, the input voltage Vin needs to be removed and then the power supply is restarted to release the over-temperature protection lock, so that the conversion unit 100 recovers and converts the input voltage Vin to the output voltage Vo again. It is worth mentioning that, in one embodiment of the present invention, the over-temperature protection method of the controller 18 can be designed according to the working environment of the conversion unit 100, so the over-temperature protection method is not limited to the above two protection methods.

請參閱圖2B為本發明過溫度補償控制電路第一實施例的偵測電路之細部電路示意圖，復配合參閱圖1~2A。偵測電路30包括電壓偵測電路302、放大電路304及電流鏡電路306，且放大電路304耦接電壓偵測電路302與電流鏡電路306。電壓偵測電路302包括輔助感應繞組302A與分壓電路302B，且輔助感應繞組302A耦接變壓器12的初級側與分壓電路302B。輔助感應繞組302A通過電磁耦合變壓器12初級側的方式感應輔助電壓Va，使得輔助電壓Va的電壓值大小響應輸入電壓Vin電壓值的大小。當輸入電壓Vin的電壓值越大時輔助電壓Va越大，且當輸入電壓Vin的電壓值越小時輔助電壓Va越小。其中，輔助感應繞組302A恰與變壓器12的初級側繞組極性相反，使得輔助感應繞組302A所感應到的輔助電壓Va為負電壓值。分壓電路302B包括串聯的第一電阻R1與第二電阻R2，且輔助電壓Va通過第一電阻R1與第二電阻R2的分壓，在第一電阻R1與第二電阻R2之間產生電壓訊號Sv。放大電路304包括二極體D、第一分壓電路(R3、R4)、電壓源Vs、回授迴路(R5、R6)及放大器OP。二極體D耦接第一電阻R1、第二電阻R2及第一分壓電路(R3、R4)，且第一分壓電路(R3、R4)耦接電壓源Vs與放大器OP的正端(+)。回授迴路(R5、R6)耦接放大器OP的負端(-)與輸出端OUT，且放大器OP的輸出端OUT耦接電流鏡電路306。二極體D防止電壓訊號Sv與電壓源Vs的電壓差而產生往電壓源Vs方向的電流路徑，第一分壓電路(R3、R4)與回授迴路(R5、R6)提供放大增益，使得放大電路304能夠將電壓訊號Sv反向放大為正電壓值的電壓調整訊號Sa，電壓調整訊號Sa的電壓值反比於輸入電壓Vin的電壓值。進一步而言，輸入電壓經整流單元將電壓轉成直流電源，而直流電源可耦合到輔助繞組的負壓，藉由輔助繞組的負壓高低來判斷輸入電壓是高壓或低壓，所以在偵測訊號時，僅擷取負壓訊號判斷即可。電流鏡電路306包括電流產生電路306A與電流鏡單元306B，電流產生電路306A耦接放大器OP的輸出端OUT與電流鏡單元306B，且電流鏡單元306B耦接溫控電阻32與比較單元34。電壓調整訊號Sa通過電流產生電路306A產生電流調整訊號Sr，且電流鏡單元306B鏡像的產生對應電流調整訊號Sr的電流訊號Si(意即，電流訊號Si為K倍的電流調整訊號Sr，且K為常數)。其中，電流訊號Si的電流值反比於輸入電壓Vin的電壓值。 Please refer to FIG. 2B for a detailed circuit diagram of the detection circuit of the first embodiment of the over-temperature compensation control circuit of the present invention, and refer to FIGS. 1 to 2A for complex cooperation. The detection circuit 30 includes a voltage detection circuit 302, an amplifying circuit 304, and a current mirror circuit 306, and the amplifying circuit 304 is coupled to the voltage detection circuit 302 and the current mirror circuit 306. The voltage detection circuit 302 includes an auxiliary induction winding 302A and a voltage dividing circuit 302B, and the auxiliary induction winding 302A is coupled to the primary side of the transformer 12 and the voltage dividing circuit 302B. The auxiliary induction winding 302A induces the auxiliary voltage Va through the primary side of the electromagnetic coupling transformer 12 so that the voltage value of the auxiliary voltage Va responds to the voltage value of the input voltage Vin. When the voltage value of the input voltage Vin is larger, the auxiliary voltage Va is larger, and when the voltage value of the input voltage Vin is smaller, the auxiliary voltage Va is smaller. Wherein, the auxiliary induction winding 302A has the opposite polarity to the primary winding of the transformer 12, so that the auxiliary voltage Va induced by the auxiliary induction winding 302A is a negative voltage value. The voltage divider circuit 302B includes a first resistor R1 and a second resistor R2 connected in series, and the auxiliary voltage Va is divided by the first resistor R1 and the second resistor R2 to generate a voltage between the first resistor R1 and the second resistor R2 Signal Sv. The amplifying circuit 304 includes a diode D, a first voltage divider circuit (R3, R4), a voltage source Vs, a feedback loop (R5, R6), and an amplifier OP. The diode D is coupled to the first resistor R1, the second resistor R2 and the first voltage divider circuit (R3, R4), and the first voltage divider circuit (R3, R4) is coupled to the voltage source Vs and the positive of the amplifier OP End (+). The feedback loop (R5, R6) is coupled to the negative terminal (-) of the amplifier OP and the output terminal OUT, and the output terminal OUT of the amplifier OP is coupled to the current mirror circuit 306. The diode D prevents the voltage difference between the voltage signal Sv and the voltage source Vs from generating a current path in the direction of the voltage source Vs. The first voltage divider circuit (R3, R4) and the feedback loop (R5, R6) provide amplification gain, The amplifying circuit 304 can reversely amplify the voltage signal Sv into a voltage adjustment signal Sa of a positive voltage value, and the voltage of the voltage adjustment signal Sa The value is inversely proportional to the voltage value of the input voltage Vin. Furthermore, the input voltage is converted into a DC power supply by the rectifier unit, and the DC power supply can be coupled to the negative voltage of the auxiliary winding. The negative voltage of the auxiliary winding is used to determine whether the input voltage is high or low voltage, so the signal is detected When it is time, only the negative pressure signal can be captured for judgment. The current mirror circuit 306 includes a current generating circuit 306A and a current mirror unit 306B. The current generating circuit 306A is coupled to the output terminal OUT of the amplifier OP and the current mirror unit 306B, and the current mirror unit 306B is coupled to the temperature control resistor 32 and the comparison unit 34. The voltage adjustment signal Sa generates a current adjustment signal Sr through the current generation circuit 306A, and the current mirror unit 306B mirrors the current signal Si corresponding to the current adjustment signal Sr (meaning that the current signal Si is K times the current adjustment signal Sr, and K Is a constant). Among them, the current value of the current signal Si is inversely proportional to the voltage value of the input voltage Vin.

請參閱圖2C為本發明第一實施例的輸入電壓、電流訊號及溫度波形圖，復配合參閱圖1~2B。以圖2A~2B為例，輸入電壓為90V~264V時，假設電壓調整訊號Sa為1.5V~1V，使得電流訊號Si為150uA~100uA流向溫控電阻32。假設比較單元34的參考電壓Vr設定為1V的情況且輸入電壓Vin為90V時，溫控電阻32的過溫度保護阻值會落在1V/150uA=6.66KΩ(假設對應過溫度保護點110℃)，且輸入電壓Vin為264V時，溫控電阻32的過溫度保護阻值會落在1V/100uA=10KΩ(假設對應過溫度保護點95℃)。因此可繪出過溫度保護點曲線A。由此曲線A可看出，當輸入電壓Vin越低時過溫度保護點越高，且輸入電壓Vin越高時過溫度保護點越低。藉此可提供動態的過溫度保護點，使得輸入電壓Vin較高時，過溫度補償控制電路300仍然能夠提供正確的過溫度保護點。 Please refer to FIG. 2C for the input voltage, current signal and temperature waveform diagrams of the first embodiment of the present invention, and for complex cooperation, refer to FIGS. 1 to 2B. Taking FIGS. 2A-2B as an example, when the input voltage is 90V~264V, it is assumed that the voltage adjustment signal Sa is 1.5V~1V, so that the current signal Si is 150uA~100uA flowing to the temperature control resistor 32. Assuming that the reference voltage Vr of the comparison unit 34 is set to 1V and the input voltage Vin is 90V, the over-temperature protection resistance of the temperature control resistor 32 will fall at 1V/150uA=6.66KΩ (assuming the corresponding over-temperature protection point is 110°C) And when the input voltage Vin is 264V, the over-temperature protection resistance of the temperature control resistor 32 will fall at 1V/100uA=10KΩ (assuming it corresponds to the over-temperature protection point of 95°C). Therefore, the over-temperature protection point curve A can be drawn. It can be seen from curve A that the over-temperature protection point is higher when the input voltage Vin is lower, and the over-temperature protection point is lower when the input voltage Vin is higher. In this way, a dynamic over-temperature protection point can be provided, so that when the input voltage Vin is high, the over-temperature compensation control circuit 300 can still provide a correct over-temperature protection point.

舉例來說，若輸入電壓Vin為90V時，輸入電流相對較大()，在輸出電流固定在滿載下，初級側與次級測零件處在高溫。例如，在初級測與次級側零件溫度(例如100℃)時，。據此，在輸入電壓Vin為90V時，偵測電路30調整其輸出的電流訊號為150uA，使得過溫點的溫度設定為110℃。換言之，若輸入電壓Vin為90V時，當溫控電阻32因溫度增加使得其電阻值小至低於6.66KΩ時，才判斷有過溫情況發生。 For example, if the input voltage Vin is 90V, the input current is relatively large (), when the output current is fixed at full load, the primary side and the secondary test parts are at high temperature. For example, in the primary measurement and secondary side parts temperature (for example, 100 ℃). Accordingly, when the input voltage Vin is 90V, the detection circuit 30 adjusts its output current signal to 150uA, so that the temperature of the over-temperature point is set to 110°C. In other words, if When the input voltage Vin is 90V, when the resistance value of the temperature control resistor 32 is lower than 6.66KΩ due to the temperature increase, it is judged that an over-temperature situation has occurred.

另一方面，若輸入電壓Vin為264V時，輸入電流相對較小()，在輸出電流固定在滿載下，導致初級側零件溫度較低(相對次級側零件溫度)。例如，在次級側零件溫度(例如100℃)時，初級側零件溫度可能仍在80℃，若是電流訊號為150uA，過溫點的溫度設定為110℃，此時次級側溫度會上升到130deg，造成次級側零件溫度過高。據此，在輸入電壓Vin為264V時，偵測電路30調整其輸出的電流訊號為100uA，使得過溫點的溫度設定為95℃。換言之，若輸入電壓Vin為264V時，當溫控電阻32因溫度增加使得其電阻值小至低於10KΩ時，便判斷有過溫情況發生。 On the other hand, if the input voltage Vin is 264V, the input current is relatively small (), and the output current is fixed at full load, resulting in lower temperature of the primary side parts (relative to the temperature of the secondary side parts). For example, at the temperature of the secondary side parts (such as 100°C), the temperature of the primary side parts may still be 80°C. If the current signal is 150uA, the temperature of the over-temperature point is set to 110°C, and the secondary side temperature will rise to 130deg, causing the temperature of the secondary side parts to be too high. Accordingly, when the input voltage Vin is 264V, the detection circuit 30 adjusts its output current signal to 100uA, so that the temperature of the over-temperature point is set to 95°C. In other words, if the input voltage Vin is 264V, when the resistance value of the temperature control resistor 32 is as small as less than 10KΩ due to the increase in temperature, it is determined that an over-temperature situation has occurred.

請參閱圖3A為本發明過溫度補償控制電路第二實施例之電路方塊示意圖，復配合參閱圖1~2C。過溫度補償控制電路300’包括偵測電路30’、溫控電阻32及比較單元34，且溫控電阻32耦接比較單元34。偵測電路30’的一端耦接整流單元10或輸入電壓Vin，且另一端耦接比較單元34。偵測電路30’根據響應輸入電壓Vin的電壓訊號Sv而提供響應輸入電壓Vin的參考電壓Vr，且參考電壓Vr的電壓值正比於輸入電壓Vin的電壓值。溫控電阻32可以為負溫度係數的熱敏電阻。當電流訊號Si(此電流為定值，例如100uA)流過溫控電阻32時，在溫控電阻32上產生溫控電壓Vc。比較單元34比較溫控電壓Vc與參考電壓Vr，且根據比較結果而提供控制訊號Sc，控制訊號Sc的數值代表轉換單元100(變壓器12初級側)的溫度是否達到過溫度保護點。在一實施例中，控制訊號Sc為邏輯準位訊號。當參考電壓Vr大於或等於溫控電壓Vc時，控制訊號Sc為高邏輯準位訊號，此時代表發生過溫情況，而當參考電壓Vr小於溫控電壓Vc時，控制訊號Sc為低邏輯準位訊號，此時代表沒發生過溫情況。請參閱圖3B為本發明過溫度補償控制電路第一實施例的偵測電路之細部電路示意圖，復配合參閱圖1~3A。偵測電路30’包括電壓偵測電路302’、比較電路308及電壓選擇電路310，且比較電路308耦接電壓偵測電路302’與電壓選擇電路310。電壓偵測電路302’可以為將交流的輸入電壓Vin轉換為電壓訊號Sv的轉換單元，將直流電壓Vd分壓為電壓訊號Sv的分壓電路，或是將直流電壓Vd傳輸至比較電路308的傳輸路徑(意即，直流電壓Vd即為電壓訊號Sv)。具體而言，由於偵測電路30’耦接輸入電壓Vin時，交流的輸入電壓Vin無法直接提供給比較電路308，因此必須額外多一級轉換單元將交流的輸入電壓Vin轉換為直流的電壓訊號Sv。此外，由於整流單元10會將90V~264V的交流電壓整流為127V~373V的直流電壓Vd，若是比較電路308的耐壓不足時，直流電壓Vd仍需經過分壓電路分壓為較小電壓值的電壓訊號Sv，方可供應給比較電路308。但是若比較電路308的耐壓足夠時，直流電壓Vd可直接傳輸給比較電路308。此時電壓偵測電路302’即可為導線而提供傳輸路徑，且直流電壓Vd即為電壓訊號Sv。其中，當輸入電壓Vin的電壓值越大時直流電壓Vd越大，且當輸入電壓Vin的電壓值越小時直流電壓Vd越小。 Please refer to FIG. 3A for the circuit block diagram of the second embodiment of the over-temperature compensation control circuit of the present invention, and refer to FIGS. 1 to 2C for complex cooperation. The over-temperature compensation control circuit 300' includes a detection circuit 30', a temperature control resistor 32, and a comparison unit 34, and the temperature control resistor 32 is coupled to the comparison unit 34. One end of the detection circuit 30' is coupled to the rectifier unit 10 or the input voltage Vin, and the other end is coupled to the comparison unit 34. The detection circuit 30' provides a reference voltage Vr in response to the input voltage Vin according to the voltage signal Sv in response to the input voltage Vin, and the voltage value of the reference voltage Vr is proportional to the voltage value of the input voltage Vin. The temperature control resistor 32 may be a thermistor with a negative temperature coefficient. When the current signal Si (the current is a constant value, such as 100 uA) flows through the temperature control resistor 32, a temperature control voltage Vc is generated on the temperature control resistor 32. The comparison unit 34 compares the temperature control voltage Vc with the reference voltage Vr, and provides a control signal Sc according to the comparison result. The value of the control signal Sc represents whether the temperature of the conversion unit 100 (primary side of the transformer 12) reaches the over-temperature protection point. In one embodiment, the control signal Sc is a logic level signal. When the reference voltage Vr is greater than or equal to the temperature control voltage Vc, the control signal Sc is a high logic level signal, which represents an over-temperature condition, and when the reference voltage Vr is less than the temperature control voltage Vc, the control signal Sc is a low logic level signal Bit signal, at this time, it means that no over-temperature has occurred. Please refer to FIG. 3B for a detailed circuit schematic diagram of the detection circuit of the first embodiment of the over-temperature compensation control circuit of the present invention, and for cooperation, refer to FIGS. 1 to 3A. Detect The test circuit 30' includes a voltage detection circuit 302', a comparison circuit 308, and a voltage selection circuit 310, and the comparison circuit 308 is coupled to the voltage detection circuit 302' and the voltage selection circuit 310. The voltage detection circuit 302' may be a conversion unit that converts the AC input voltage Vin into a voltage signal Sv, divides the DC voltage Vd into a voltage signal Sv, or transmits the DC voltage Vd to the comparison circuit 308 The transmission path (that is, the DC voltage Vd is the voltage signal Sv). Specifically, since the AC input voltage Vin cannot be directly provided to the comparison circuit 308 when the detection circuit 30' is coupled to the input voltage Vin, an additional stage of conversion unit is required to convert the AC input voltage Vin into a DC voltage signal Sv . In addition, since the rectifier unit 10 rectifies the AC voltage of 90V~264V to the DC voltage Vd of 127V~373V, if the withstand voltage of the comparison circuit 308 is insufficient, the DC voltage Vd still needs to be divided into a smaller voltage by the voltage divider circuit The voltage signal Sv of the value can be supplied to the comparison circuit 308. However, if the withstand voltage of the comparison circuit 308 is sufficient, the DC voltage Vd can be directly transmitted to the comparison circuit 308. At this time, the voltage detection circuit 302' can provide a transmission path for the wire, and the DC voltage Vd is the voltage signal Sv. Wherein, when the voltage value of the input voltage Vin is larger, the DC voltage Vd is larger, and when the voltage value of the input voltage Vin is smaller, the DC voltage Vd is smaller.

比較電路308包括第一比較單元308A與第二比較單元308B，且第一比較單元308A的負端(-)與第二比較單元308B的正端(+)接收電壓訊號Sv。第一比較單元308A的正端(+)與第二比較單元308B的負端(-)接收閥值電壓Vt，且第一比較單元308A與第二比較單元308B分別比較電壓訊號Sv與閥值電壓Vt，以提供驅動訊號Sd。其中，驅動訊號Sd包括第一驅動訊號Sd1與第二驅動訊號Sd2。具體而言，當電壓訊號Sv的電壓值小於閥值電壓Vt的電壓值時，第一比較單元308A提供第一驅動訊號Sd1，且當電壓訊號Sv的電壓值大於或等於閥值電壓Vt的電壓值時，第二比較單元308B提供第二驅動訊號Sd2。其中，閥值電壓Vt即為過電壓保護點的轉折點。例如但不限於，當閥值電壓Vt對應輸入電壓Vin範圍的中點時(意即，177V)，在輸入電壓Vin為90V~177V時，第一比較單元 308A提供第一驅動訊號Sd1，且在輸入電壓Vin為177V~264V時，第二比較單元308B提供第二驅動訊號Sd2。 The comparison circuit 308 includes a first comparison unit 308A and a second comparison unit 308B, and the negative terminal (-) of the first comparison unit 308A and the positive terminal (+) of the second comparison unit 308B receive the voltage signal Sv. The positive terminal (+) of the first comparison unit 308A and the negative terminal (-) of the second comparison unit 308B receive the threshold voltage Vt, and the first comparison unit 308A and the second comparison unit 308B compare the voltage signal Sv with the threshold voltage, respectively Vt to provide the driving signal Sd. The driving signal Sd includes a first driving signal Sd1 and a second driving signal Sd2. Specifically, when the voltage value of the voltage signal Sv is less than the voltage value of the threshold voltage Vt, the first comparison unit 308A provides the first driving signal Sd1, and when the voltage value of the voltage signal Sv is greater than or equal to the voltage value of the threshold voltage Vt When the value is set, the second comparison unit 308B provides the second driving signal Sd2. Among them, the threshold voltage Vt is the turning point of the overvoltage protection point. For example, but not limited to, when the threshold voltage Vt corresponds to the midpoint of the input voltage Vin range (that is, 177V), when the input voltage Vin is 90V~177V, the first comparison unit 308A provides the first driving signal Sd1, and when the input voltage Vin is 177V~264V, the second comparing unit 308B provides the second driving signal Sd2.

電壓選擇電路310包括串聯的第一開關Q1與第二開關Q2，且第一開關Q1與第二開關Q2之間的接點耦接比較單元34。參考電壓Vr包括第一參考電壓Vr1與第二參考電壓Vr2，且第一開關Q1的另一端接收第一參考電壓Vr1，第二開關Q2的另一端接收第二參考電壓Vr2。第一開關Q1的控制端耦接第一比較單元308A，且第二開關Q2的控制端耦接第二比較單元308B。第一開關Q1根據第一驅動訊號Sd1而導通，使電壓選擇電路310提供第一參考電壓Vr1至比較單元34，且第二開關Q2根據第二驅動訊號Sd2而導通，使電壓選擇電路310提供第二參考電壓Vr2至比較單元34。其中，第二參考電壓Vr2的電壓值大於第一參考電壓Vr1，使得電壓選擇電路310在較小的輸入電壓Vin會對應地輸出第一參考電壓Vr1，且在較大的輸入電壓Vin會對應地輸出第二參考電壓Vr2。 The voltage selection circuit 310 includes a first switch Q1 and a second switch Q2 connected in series, and the contact point between the first switch Q1 and the second switch Q2 is coupled to the comparison unit 34. The reference voltage Vr includes a first reference voltage Vr1 and a second reference voltage Vr2, and the other end of the first switch Q1 receives the first reference voltage Vr1, and the other end of the second switch Q2 receives the second reference voltage Vr2. The control terminal of the first switch Q1 is coupled to the first comparison unit 308A, and the control terminal of the second switch Q2 is coupled to the second comparison unit 308B. The first switch Q1 is turned on according to the first driving signal Sd1, so that the voltage selection circuit 310 provides the first reference voltage Vr1 to the comparing unit 34, and the second switch Q2 is turned on according to the second driving signal Sd2, so that the voltage selection circuit 310 provides the first reference voltage Vr1. Two reference voltages Vr2 to the comparison unit 34. Wherein, the voltage value of the second reference voltage Vr2 is greater than the first reference voltage Vr1, so that the voltage selection circuit 310 will output the first reference voltage Vr1 correspondingly when the input voltage Vin is small, and will correspondingly output the first reference voltage Vr1 when the input voltage Vin is relatively large. The second reference voltage Vr2 is output.

請參閱圖3C為本發明第二實施例的輸入電壓、電流訊號及溫度波形圖，復配合參閱圖1~3B。以圖3A~3B為例，假設輸入電壓Vin為90V~264V、閥值電壓Vt的電壓值對應輸入電壓Vin為177V、電流訊號Si為100uA，且第一參考電壓Vr1為1V(假設對應過溫度保護點110℃)、第二參考電壓Vr2為1.5V(假設對應過溫度保護點95℃)。在輸入電壓Vin為90V~177V時，第一比較單元308A提供第一驅動訊號Sd1，使得第一開關Q1導通而提供1V的參考電壓Vr。此時，溫控電阻32的過溫度保護阻值會落在1V/100uA=10KΩ。在輸入電壓Vin為177V~264V時，第二比較單元308B提供第二驅動訊號Sd2，使得第二開關Q2導通而提供1.5V的參考電壓Vr。此時，溫控電阻32的過溫度保護阻值會落在1.5V/100uA=15KΩ。因此可繪出具有轉折點X的過溫度保護點曲線B。由此曲線B可看出，當輸入電壓Vin低於轉折點X時過溫度保護點較高，且輸入電壓 Vin高於轉折點X時過溫度保護點較低。藉此可提供動態的過溫度保護點，使得輸入電壓Vin較高時，過溫度補償控制電路300仍然能夠提供正確的過溫度保護點。值得一提，於本發明之一實施例中，過溫度保護點可設計多個轉折點X。意即，比較電路308具有多個比較單元，且包括多個閥值電壓，以及搭配多個比較單元的開關與參考電壓。其電路結構於運作方式相似於圖3A~3B，在此不再加以贅述。 Please refer to FIG. 3C for the input voltage, current signal and temperature waveform diagrams of the second embodiment of the present invention, and for complex cooperation, refer to FIGS. 1 to 3B. Taking Figures 3A~3B as an example, suppose the input voltage Vin is 90V~264V, the threshold voltage Vt corresponds to the input voltage Vin of 177V, the current signal Si is 100uA, and the first reference voltage Vr1 is 1V (assuming the corresponding over-temperature The protection point is 110°C), and the second reference voltage Vr2 is 1.5V (assuming it corresponds to the over-temperature protection point of 95°C). When the input voltage Vin is 90V~177V, the first comparison unit 308A provides the first driving signal Sd1, so that the first switch Q1 is turned on to provide a reference voltage Vr of 1V. At this time, the over-temperature protection resistance value of the temperature control resistor 32 will fall at 1V/100uA=10KΩ. When the input voltage Vin is between 177V and 264V, the second comparison unit 308B provides the second driving signal Sd2, so that the second switch Q2 is turned on to provide a reference voltage Vr of 1.5V. At this time, the over-temperature protection resistance value of the temperature control resistor 32 will fall at 1.5V/100uA=15KΩ. Therefore, the over-temperature protection point curve B with the turning point X can be drawn. It can be seen from curve B that when the input voltage Vin is lower than the turning point X, the over-temperature protection point is higher, and the input voltage When Vin is higher than the turning point X, the over-temperature protection point is lower. In this way, a dynamic over-temperature protection point can be provided, so that when the input voltage Vin is high, the over-temperature compensation control circuit 300 can still provide a correct over-temperature protection point. It is worth mentioning that in one embodiment of the present invention, the over-temperature protection point can be designed with multiple turning points X. That is, the comparison circuit 308 has a plurality of comparison units, and includes a plurality of threshold voltages, and switches and reference voltages associated with the plurality of comparison units. Its circuit structure and operation mode are similar to those in FIGS. 3A to 3B, and will not be repeated here.

惟，以上所述，僅為本發明較佳具體實施例之詳細說明與圖式，惟本發明之特徵並不侷限於此，並非用以限制本發明，本發明之所有範圍應以下述之申請專利範圍為準，凡合於本發明申請專利範圍之精神與其類似變化之實施例，皆應包括於本發明之範疇中，任何熟悉該項技藝者在本發明之領域內，可輕易思及之變化或修飾皆可涵蓋在以下本案之專利範圍。此外，在申請專利範圍和說明書中提到的特徵可以分別單獨地或按照任何組合方式來實施。 However, the above are only detailed descriptions and drawings of the preferred embodiments of the present invention. However, the features of the present invention are not limited to these, and are not intended to limit the present invention. The full scope of the present invention should be referred to the following application The scope of the patent shall prevail. All embodiments that conform to the spirit of the scope of the patent application of the present invention and similar variations should be included in the scope of the present invention. Anyone familiar with the art in the field of the present invention can easily think of it. Changes or modifications can be covered in the following patent scope of this case. In addition, the features mentioned in the scope of the patent application and the specification can be implemented individually or in any combination.

100:轉換單元 100: conversion unit

10:整流單元 10: Rectifier unit

12:變壓器 12: Transformer

14:切換單元 14: Switching unit

16:輸出電路 16: output circuit

18:控制器 18: Controller

200:負載 200: load

300:溫度補償控制電路 300: Temperature compensation control circuit

Vin:輸入電壓 Vin: input voltage

Vo:輸出電壓 Vo: output voltage

Vd:直流電壓 Vd: DC voltage

Claims

一種過溫度補償控制電路，耦接一轉換單元，該過溫度補償控制電路包括：一偵測電路，耦接該轉換單元，用以根據響應於提供給該轉換單元的一輸入電壓的一電壓訊號而提供響應於該輸入電壓的一電流訊號；一溫控電阻，耦接該偵測電路，用以根據該電流訊號產生一溫控電壓；及一比較單元，耦接該溫控電阻，用以比較該溫控電壓與一參考電壓而產生一控制訊號；其中，該控制訊號代表該轉換單元的一溫度是否達到一過溫度保護點。 An over-temperature compensation control circuit is coupled to a conversion unit. The over-temperature compensation control circuit includes: a detection circuit coupled to the conversion unit for responding to a voltage signal in response to an input voltage provided to the conversion unit A current signal in response to the input voltage is provided; a temperature control resistor is coupled to the detection circuit for generating a temperature control voltage according to the current signal; and a comparison unit is coupled to the temperature control resistor for Comparing the temperature control voltage with a reference voltage to generate a control signal; wherein, the control signal represents whether a temperature of the conversion unit reaches an over-temperature protection point.

如申請專利範圍第1項所述之過溫度補償控制電路，其中當該輸入電壓越大，該偵測電路調整該電流訊號使該電流訊號越小。 Such as the over-temperature compensation control circuit described in item 1 of the scope of patent application, wherein when the input voltage is larger, the detection circuit adjusts the current signal to make the current signal smaller.

如申請專利範圍第2項所述之過溫度補償控制電路，其中當該溫控電壓小於該參考電壓時，代表該轉換單元的該溫度超過該過溫度保護點。 For example, in the over-temperature compensation control circuit described in item 2 of the scope of patent application, when the temperature control voltage is less than the reference voltage, it means that the temperature of the conversion unit exceeds the over-temperature protection point.

如申請專利範圍第1項所述之過溫度補償控制電路，其中該偵測電路包括：一電壓偵測電路，耦接該轉換單元，用以接收響應該輸入電壓的一輔助電壓，且根據該輔助電壓而提供一電壓訊號；一放大電路，耦接該電壓偵測電路，用以將該電壓訊號放大為一電壓調整訊號；及一電流鏡電路，耦接該放大電路、該溫控電阻及該比較單元，用以根據響應該電壓調整訊號的一電流調整訊號鏡像地產生該電流訊號。 For the over-temperature compensation control circuit described in claim 1, wherein the detection circuit includes: a voltage detection circuit, coupled to the conversion unit, for receiving an auxiliary voltage in response to the input voltage, and according to the Auxiliary voltage to provide a voltage signal; an amplifier circuit coupled to the voltage detection circuit for amplifying the voltage signal into a voltage adjustment signal; and a current mirror circuit coupled to the amplifier circuit, the temperature control resistor, and The comparison unit is used for generating the current signal in a mirror image according to a current adjustment signal in response to the voltage adjustment signal.

如申請專利範圍第4項所述之過溫度補償控制電路，其中該電壓偵測電路包括：一輔助感應繞組，耦接該轉換單元的一變壓器；及一分壓電路，耦接該輔助感應繞組；其中，該輔助感應繞組通過電磁耦合該變壓器的方式感應該輔助電壓，且該分壓電路將該輔助電壓分壓為該電壓訊號。 The over-temperature compensation control circuit described in item 4 of the scope of patent application, wherein the voltage detection circuit includes: An auxiliary induction winding coupled to a transformer of the conversion unit; and a voltage dividing circuit coupled to the auxiliary induction winding; wherein the auxiliary induction winding induces the auxiliary voltage by electromagnetically coupling the transformer, and the divided voltage The circuit divides the auxiliary voltage into the voltage signal.

如申請專利範圍第4項所述之過溫度補償控制電路，其中擷取該輔助電壓為負值，該電流訊號反比於該輸入電壓，且該溫控電阻的電阻值反比於該溫度。 For the over-temperature compensation control circuit described in item 4 of the scope of patent application, the auxiliary voltage is extracted as a negative value, the current signal is inversely proportional to the input voltage, and the resistance value of the temperature control resistor is inversely proportional to the temperature.

如申請專利範圍第1項所述之過溫度補償控制電路，其中該控制訊號係提供至一控制器，該控制器設定一溫度磁滯區間，該溫度磁滯區間包括該過溫度保護點與一低溫度復歸點；當該控制器根據該控制訊號得知該轉換單元的該溫度達到該過溫度保護點時，該控制器關閉該轉換單元，且待該轉換單元的該溫度下降至該低溫度復歸點時，該控制器復歸該轉換單元。 For example, the over-temperature compensation control circuit described in item 1 of the scope of patent application, wherein the control signal is provided to a controller, and the controller sets a temperature hysteresis interval, and the temperature hysteresis interval includes the over-temperature protection point and a Low temperature reset point; when the controller knows that the temperature of the conversion unit reaches the over temperature protection point according to the control signal, the controller turns off the conversion unit, and waits for the temperature of the conversion unit to drop to the low temperature When returning to the point, the controller returns to the conversion unit.

如申請專利範圍第1項所述之過溫度補償控制電路，其中該控制訊號係提供至一控制器，當該控制器根據該控制訊號得知該轉換單元的該溫度達到該過溫度保護點時，該控制器控制鎖定該轉換單元。 For example, the over-temperature compensation control circuit described in item 1 of the scope of patent application, wherein the control signal is provided to a controller, when the controller knows that the temperature of the conversion unit reaches the over-temperature protection point according to the control signal , The controller controls and locks the conversion unit.

一種過溫度補償控制電路，耦接一轉換單元，該過溫度補償控制電路包括：一偵測電路，耦接該轉換單元，用以根據響應一輸入電壓的一電壓訊號而提供響應該輸入電壓的一參考電壓；一溫控電阻，用以根據一電流訊號產生一溫控電壓；及一比較單元，耦接該偵測電路和該溫控電阻，用以比較該溫控電壓與該參考電壓而產生一控制訊號；其中，該控制訊號代表該轉換單元的一溫度是否達到一過溫度保護點。 An over-temperature compensation control circuit is coupled to a conversion unit. The over-temperature compensation control circuit includes: a detection circuit, coupled to the conversion unit, for providing a response to an input voltage according to a voltage signal in response to an input voltage A reference voltage; a temperature control resistor for generating a temperature control voltage according to a current signal; and a comparison unit, coupled to the detection circuit and the temperature control resistor, for comparing the temperature control voltage with the reference voltage A control signal is generated; wherein, the control signal represents whether a temperature of the conversion unit reaches an over-temperature protection point.

如申請專利範圍第9項所述之過溫度補償控制電路，其中當響應於該輸入電壓的一電壓訊號小於一閥值電壓時，該偵測電路調整該參考電壓具有一第一參考電壓值，且該電壓訊號大於或等於該閥值電壓時，該偵測電路調整該參考電壓具有一第二參考電壓值，其中該第二參考電壓值大於該第一參考電壓值。 For example, the over-temperature compensation control circuit described in item 9 of the scope of patent application, wherein when a voltage signal in response to the input voltage is less than a threshold voltage, the detection circuit adjusts the reference voltage to have a first reference voltage value, And when the voltage signal is greater than or equal to the threshold voltage, the detection circuit adjusts the reference voltage to have a second reference voltage value, wherein the second reference voltage value is greater than the first reference voltage value.

如申請專利範圍第9項所述之過溫度補償控制電路，其中當該溫控電壓小於該參考電壓時，代表該轉換單元的該溫度超過該過溫度保護點。 For example, in the over-temperature compensation control circuit described in item 9 of the scope of patent application, when the temperature control voltage is less than the reference voltage, it means that the temperature of the conversion unit exceeds the over-temperature protection point.

如申請專利範圍第9項所述之過溫度補償控制電路，其中該偵測電路包括：一電壓偵測電路，耦接該轉換單元，用以接收該輸入電壓或響應該輸入電壓的一直流電壓，且根據該輸入電壓或該直流電壓而提供該電壓訊號；一比較電路，耦接該電壓偵測電路，用以比較該電壓訊號與一閥值電壓而提供一驅動訊號至電壓選擇電路；及一電壓選擇電路，耦接該比較電路與該比較單元，用以根據該驅動訊號選擇合適的該參考電壓。 The over-temperature compensation control circuit described in claim 9 of the scope of patent application, wherein the detection circuit includes: a voltage detection circuit coupled to the conversion unit for receiving the input voltage or a DC voltage in response to the input voltage , And provide the voltage signal according to the input voltage or the DC voltage; a comparison circuit coupled to the voltage detection circuit for comparing the voltage signal with a threshold voltage to provide a driving signal to the voltage selection circuit; and A voltage selection circuit is coupled to the comparison circuit and the comparison unit for selecting the appropriate reference voltage according to the driving signal.

如申請專利範圍第12項所述之過溫度補償控制電路，其中該比較電路包括：一第一比較單元，接收該電壓訊號與該閥值電壓；一第二比較單元，接收該電壓訊號與該閥值電壓；其中，該驅動訊號包括一第一驅動訊號與一第二驅動訊號；該第一比較單元比較該電壓訊號與該閥值電壓而提供該第一驅動訊號至該電壓選擇電路，且該第二比較單元比較該電壓訊號與該閥值電壓而提供該第二驅動訊號至該電壓選擇電路。 For example, the over-temperature compensation control circuit described in claim 12, wherein the comparison circuit includes: a first comparison unit that receives the voltage signal and the threshold voltage; a second comparison unit that receives the voltage signal and the threshold voltage Threshold voltage; wherein the driving signal includes a first driving signal and a second driving signal; the first comparing unit compares the voltage signal with the threshold voltage to provide the first driving signal to the voltage selection circuit, and The second comparison unit compares the voltage signal with the threshold voltage to provide the second driving signal to the voltage selection circuit.

如申請專利範圍第12項所述之過溫度補償控制電路，其中該電壓選擇電路包括：一第一開關，耦接該比較電路與該比較單元，且接收一第一參考電壓；一第二開關，耦接該比較電路與該比較單元，且接收一第二參考電壓；其中，該電壓選擇電路根據該驅動訊號而導通該第一開關或該第二開關；當該第一開關導通時，該電壓選擇電路將該第一參考電壓作為該參考電壓，且當該第二開關導通時，該電壓選擇電路將該第二參考電壓作為該參考電壓。 The over-temperature compensation control circuit described in claim 12, wherein the voltage selection circuit includes: a first switch, which is coupled to the comparison circuit and the comparison unit, and receives a first reference voltage; and a second switch , Coupled to the comparison circuit and the comparison unit, and receives a second reference voltage; wherein the voltage selection circuit turns on the first switch or the second switch according to the driving signal; when the first switch is turned on, the The voltage selection circuit uses the first reference voltage as the reference voltage, and when the second switch is turned on, the voltage selection circuit uses the second reference voltage as the reference voltage.

如申請專利範圍第9項所述之過溫度補償控制電路，其中該參考電壓正比於該輸入電壓，且該溫控電阻的電阻值反比於該溫度。 The over-temperature compensation control circuit described in item 9 of the scope of patent application, wherein the reference voltage is proportional to the input voltage, and the resistance value of the temperature control resistor is inversely proportional to the temperature.