546909 A7 _____B7_ 五、發明説明（1 ) 【發明所屬之技術領域】 (請先閱讀背面之注意事項再填寫本頁) 本發明，係有關用以偵知被使用於汎用變頻器之制動 電晶體等之切換元件的故障，並用以防止變頻器及制動電 阻之異常加熱。 【先前之技術】 一般在汎用變頻器，係具備制動電阻爲了用以吸收在 發電制動及再生制動時由電動機被返流之能源，對該制動 電阻使流動電流之切換元件以任何理由發生短路故障時， 則在制動電阻引起異常發熱，最壞的情形會使制動電阻燒 損同時對周邊零件也會有波及二次性損傷之虞。 做爲將此防止裝置譬如與制動電阻以串聯安裝溫度保 險絲等，在切換元件之短路故障時係使溫度保險絲被切斷 對制動電阻用以遮斷電流之方法，但此係藉由使溫度保險 絲及制動電阻之溫度上昇速度的配合，使溫度保險絲之動 作來不及在保護裝置發揮功能之前會有使制動電阻導致燒 損之問題。 經濟部智慧財產局員工消費合作社印製 因此，用以監視制動電阻之兩端的電壓在制動電阻有 用以偵知流動電流之時間的方法。 圖5係被適用故障偵知裝置之主電路的方塊圖。圖5 中，5 1係3相電源，於此被連接有變換器5 2。變換器 5 2係由被電橋連接（未圖示）之二極體5 2 a及平滑電 容器5 2 b被構成，在該電容器5 2之輸出側係使被交直 流變換之直流電壓被輸出於正極側母線1 1及負極側母線 1 2之間。5 3係變頻部將該直流電壓進行變換成3相交 本紙張尺度適用中國國家標準（CNS ) A4規格（210X297公釐） -4 - 546909 A7 B7 五、發明説明（2 ) 流，具備有被電橋連接（未圖示）之控制用切換元件，在 該變頻部5 3之輸出側被連接有感應電動機。 如此之主電路中，2係制動電路被***於正極側母線 (請先閲讀背面之注意事項再填寫本頁) 1 1及負極側母線1 2之間，此係由制動電阻2 1及制動 電晶體2 2之串聯電路所構成。而且4係先前之故障偵知 電路用以偵知制動電晶體2 2之故障並被連接於制動電阻 2 1之兩端。對於故障偵知電路4係後述。5係邏輯電路 ，由制動電晶體2 2之閘信號S 0及故障偵知電路4之輸 出信號S 2求出邏輯構成並有預定關係時用以輸出故障信 號A 0。 圖6係先前之故障偵知電路的具體性電路構成之一例 圖。 圖6中，11係正極側母線，12係負極側母線，2 係制動電路被***於正極側母線1 1及負極側母線1 2之 間並由制動電阻2 1及制動電晶體2 2之串聯電路所構成 。4係先前之故障偵知電路用以偵知制動電晶體2 2之故 障，該故障偵知電路4係被連接於制動電阻2 1之兩端。 經濟部智慧財產局員工消費合作社印製 故障偵知電路4之構成，係使被並聯連接於制動電阻 2 1之電阻4 1 ，及在該電阻4 1由電阻42及43所構 成之串聯連接電路被連接成並聯。進而，在電阻4 3，係 使由穩壓二極體4 4及發光二極體4 5 a所構成陽極彼此 對接之串聯連接電路被連接成並聯。另外，在低電壓電源 (2 4 V )及地線間，使由電阻4 6及光電晶體4 5 b所 構成串聯連接電路將其光電晶體4 5 b之發射極E做爲地 線側並被連接。在其集極側被設有故障偵知輸出端子4 7 本紙張尺度適用中國國家標準（CNS ) A4規格（210X297公釐） -5 - 546909 A7 _B7 五、發明説明（3 ) (請先閱讀背面之注意事項再填寫本頁) 。而且，光電晶體4 5 b係與發光二極體4 5 a —起用以 構成光耦合器4 5，並使光電晶體4 5 b用以受光發光二 極體4 5 a之光則被構成能進行導通。 穩壓二極體4 4，係將其穩壓電壓做爲基準加上在此 以上之電壓時產生中斷使發光二極體4 5 a發光，所以通 常，藉由穩壓電壓以下之干擾等係不會產生誤發光，爲了 使發光動作穩定化。 電阻4 1 ，係未被連接制動電阻2 1時由於制動電晶 體2 2之洩漏電流使發光二極體4 5 a不發光並使電流偏 流之電阻。 其次，對於圖6之先前的故障偵知電路4之動作加以 說明。 制動電阻2 1之兩端電壓，即將電阻4 1之兩端電壓 在由電阻4 2及4 3所構成串聯連接電路進行分壓，並使 電阻4 3之電壓形成某設定電壓以上則使穩壓二極體4 4 產生撃穿並在發光二極體4 5 a流動電流，使發光二極體 經濟部智慧財產局員工消費合作社印製 4 5 a進行發光。將該發光使光電晶體4 5 b進行受光則 使光電晶體4 5 b進行導通。因此，由低電壓電源通過電 阻4 6及光電晶體4 5 b並在地線間使電流流動。藉此， 光電晶體4 5 b之非導通時係使輸出端子4 7之輸出信號 5 2在高電平或光電晶體4 5 b之導通後則成爲低電平。 圖7係制動電晶體2 2之閘信號及故障偵知電路4之 輸出的真理値表，圖7 ( a )係圖6之先前的故障偵知電 路之真理値表。 現在，使制動電晶體2 2之閘信號S 0爲0 (.無閘信 本紙張尺度適用中國國家標準（CNS ) A4規格（210X297公釐） 7〇1 一 546909 A7 ___ B7 五、發明説明（4 ) (請先閱讀背面之注意事項再填寫本頁) 號。即，制動電晶體2_ 2係非導通）時，則制動電阻2 1 之兩端電壓係零所以穩壓二極體4 4係不擊穿，因此發光 二極體4 5 a係不發光，藉此光電晶體4 5 b也不受光， 所以輸出端子4 7之輸出信號S 2係在高電平（1 )之狀 態。此係正常狀態。假如使制動電晶體2 2發生短路故障 ，則使制動電晶體2 2之閘信號S 0即使爲〇但在制動電 阻2 1之兩端電壓係使約線間電壓進行產生，所以使穩壓 二極體4 4進行擊穿使發光二極體4 5 a發光，因此使光 電晶體4 5 b進行導通並將輸出端子4 7之輸出信號S 2 形成減低到地線電平（0 )爲止。 因此，真理値表係S 〇 = 0使S 2 = 1爲正常狀態， S 0 = 〇使S 2 = 0爲異常狀態。 其次，使制動電晶體2 2之閘信號S 〇爲1 (有閘信 號。即制動電晶體2 2係導通狀態）時，則在制動電阻 2 1之兩端電壓係產生約線間電壓，所以使穩壓二極體 4 4進行擊穿並使發光二極體4 5 a發光，因此使光電晶 體4 5 b進行導通並將輸出端子4 7之輸出信號S 2形成 減低到地線電平（0 )爲止。此係正常狀態。 經濟部智慧財產局員工消費合作社印製 假如使制動電晶體2 2發生開放故障，則即使制動電 晶體2 2之閘信號S 0爲1 ，但制動電阻2 1之兩端電歷 係零所以穩壓二極體4 4係不撃穿，因此發光二極體 4 5 a係不發光，因而光電晶體4 5 b也不受光，所以輸 出端子4 7之輸出信號S 2係在高電平（1 )之狀態。此 係異常狀態。 因此，真理値表係S 〇 = 〇使S 2二0爲正常狀態， 本紙張尺度適用中國國家標準（CNS ) A4規格（210X 297公釐） Zj . 546909 Α7 Β7 五、發明説明（5 ) S 0 = 1使S 2 = 1爲異常狀態。 (讀先閱讀背面之注意事項再填寫本頁} 使如此之真理値表記憶於圖5之邏輯電路5放置，使 信號S 0及S 2之組合形成異常時使故障偵知信號A 〇由 邏輯電路5輸出，以該信號A 〇將***於主電路中之開關 A 1、A 2 或 A 3 V. 0 F F 狀態。 【發明所欲解決之問題】 如此，若依據先前電路則可用以偵知制動電晶體2 2 之故阶。 可是，先前電路，係爲了用以偵知制動電晶體2 2之 故障，用以監視制動電阻2 1之兩端電壓，所以對制動電 晶體使閘進行導通時被外加於制動電阻2 1之兩端的電壓 ，係使變頻器之D C母線電壓加壓，此係因爲非常高的電 壓，所以由電阻4 2及4 3所構成串聯連接電路係有必要 大的電力容量之電阻。此係形成變頻器之低成本化，小型 化的瓶頸。 經濟部智慧財產局員工消費合作社印製 在先前裝置，係使進行監視之電壓因爲非常的高，所 以電流限制用之電阻也有必要做爲非常大的電力，實裝面 積也變大。 本發明係用以解決此等問題，所以提供一種故障偵知 電路不必要大的電力容量之電阻，變頻器可低成本化，小 空間化，又，電流限制用之電阻也以小容量即足夠，實裝 面積也變小可完成。 【解決問題之手段】 本紙張尺度適用中國國家標準（CNS ) Α4規格（210X297公釐） -8 · 546909 at B7 五、發明説明（6 ) C誦先閱讀背面之注意事項4¾寫本頁} 本發明係爲了用以解決此等問題，若依據申請專利範 圍第1項所記載之制動切換元件之故障偵知電路的發明， 則使制動電阻及制動切換元件之串聯連接電路被連接於變 頻器之輸入側直流母線間被使用於形成制動電路之該切換 元件的故障偵知之故障偵知電路中，其特徵在於··在前述 制動電路中之制動切換元件及制動電阻之連接點用以連接 高耐壓二極體之陰極側且將其陽極側進行連接於低電壓電 源正側，而在前述高耐壓二極體用以利用有無流動電流並 進行變頻器之制動切換元件的偵知。 申請專利範圍第2項所記載之發明，係申請專利範圍 第1項所記載之故障偵知電路中，其特徵爲：藉由有無前 述制動切換元件之控制信號及有無前述偵知電路之偵知氣 號的邏輯組合，用以判斷前述制動切換元件之故障者。 經濟部智慧財產局員工消費合作社印製 申請專利範圍第3項所記載之發明，係申請專利範圍 第2項所記載之故障偵知電路中，其特徵爲：使前述偵知 電路具備光耦合器用以偵知發光二極體及該發光二極體之 發光並由與導通之光電晶體被構成，並使該發光二極體在 前述高耐壓二極體之陽極側及前述正側電源之間被連接成 順方向，並在前述高耐壓二極體將有無流動電流通過光耦 合器進行輸出者。 申請專利範圍第4項所記載之發明，係申請專利範圍 第3項所記載之故障偵知電路中，其特徵爲：使前述光電 晶體在正電源側及地線間通過電阻被連接，並使前述偵知 電路之偵知輸出端子對該光電晶體，A )通過電阻被設於 正電源側，或B )通過電阻被設於地線側’ A )被設於正 本紙張尺度適用中國國家標準（CNS ) A4規格（210X 297公釐） -9- 546909 A7 __B7 _ 五、發明説明（8 ) 低成本，小空間化。 (請先閲讀背面之注意事項再填寫本頁) 又，申請專利範圍第6項所記載之變頻器的發明’係 如申請專利範圍第1〜5項其中任何一項所記載之具備故 障偵知電路之變頻器中，使偵知電路之偵知結果被判斷制 動切換元件之故障時，具備用以立刻遮斷流入於制動電阻 之電流的裝置者。 藉此，用以偵知變頻器內之制動切換元件之故障時， 立刻進行遮斷可防止制動電阻之過熱將安全的變頻器以低 成本，小空間化可製作。 【發明之實施形態】 經濟部智慧財產局員工消費合作社印製 圖1係有關本發明第1實施形態被適用故障偵知裝置 之主電路的方塊圖。圖1中，5 1係3相電源，於此被連 接有變換器5 2。變換器5 2係由被電橋連接（未圖示） 之二極體5 2 a及平滑動容器5 2 b被構成，而在該變換 器5 2之輸出側係使交直流變換之直流電壓被輸出於正極 側母線1 1及負極側母線1 2之間。5 3係變頻器部將該 直流電壓進行變換成3相交流，具備有被電橋連接（未圖 示）之控制用切換元件，並在該變頻器部5 3之輸出側被 連接有感應電動機5 4。 如此之主電路中，2係制動電路被***於正極側母線 1 1及負極側母線1 2之間，此係由制動電阻2 1及制動 電晶體2 2之串聯電路所構成。而且3係有關本發明之故 障偵知電路用以偵知制動電晶體2 2之故障，在制動電阻 2 1及制動電晶體2 2.之連接點P被連接。對於該故障偵 本紙張尺度適用中國國家標準（CNS ) A4規格（21〇><297公釐) 7γ\Ζ " 546909 A7 _ B7 _ 五、發明説明（9 ) (請先閱讀背面之注意事項再填寫本頁) 知電路3係後述。5係邏輯電路，使制動電晶體2 2之閘 信號S 〇及故障偵知電路3之輸出信號S 1之邏輯組合有 預定關係時用以輸出故障信號A 0，並使用該故障信號 A 0使電路保護進行。 圖2係有關本發明第1實施形態之故障偵知裝置。 圖2中，1 1係正極側母線，1 2係負極側母線’ 2 係制動電阻被***於正極側母線1 1及負極側母線1 2之 間由制動電阻2 1及制動電晶體2 2之串聯電路所構成。 3係本發明之故障偵知電路用以偵知制動電晶體2 2之故 障，該故障偵知電路3係在制動電阻2 1及制動電晶體 2 2之連接點P被連接。 故障偵知電路3之構成，係在2 4 V之低電壓電源L 使被連接成順方向之發光二極體3 3 a及電阻3 2及被連 接成順方向之高耐壓二極體3 1所構成之串聯連接電路在 制動電阻2 1及制動電晶體2 2之連接點被連接。 經濟部智慧財產局員工消費合作社印製 另外，在低電壓電源L ( 2 4 V )及地線間，使由電 阻3 4及光電晶體3 3 b所構成之串聯連接電路使其光電 晶體3 3 b之發射極側E做爲地線側被連接。在其集極側 C使故障偵知輸出端子3 5被設置。而且，光電晶體 3 3 b係與發光二極體3 3 a —起用以構成光耦合器3 3 ，並使光電晶體3 3 b用以受光發光二極體3 3 a之光則 被構成能進行導通。 其次，對於圖2之故障偵知電路之動作加以說明。 使制動電晶體2 2非導通時，在制動電晶體2 2之集 極C係通過電阻2 1使D C母線電壓直接被外加，所以在 本紙張尺度適用中國國家標準（CNS ) A4規格（210X297公H -12 - " "" 546909 A7 _____B7_ 五、發明説明（ (請先閲讀背面之注意事項再填寫本頁) 高耐壓二極體3 1係形成反方向電壓，使D C母線電壓藉 由高耐壓二極體3 1被調節。因此，發光二極體3 3 a係 不發光，所以使光電晶體3 3 b不導通，輸出端子4 7之 輸出信號S 2 1係高電平（1 )之狀態。 又，使制動電晶體2 2導通時，係使制動電晶體2 2 之集極C約形成2 V程度，並使高耐壓二極體3 1進行導 通，經由電阻3 2爲了使發光二極體3 3 a進行發光，將 該發光使光電晶體3 3 b進行受光則光電晶體3 3 b係進 行導通。因此，由低電壓電源通過電阻3 4及光電晶體 3 3 b在地線間使電流流動。藉此，使輸出端子3 5之輸 出信號S 1在高電平或光電晶體3 3 b之導通後係形成低 電平（0 )。 圖7係制動電晶體2 2之閘信號S 0及故障偵知電路 4之輸出信號S 1之真理値表，圖7 ( b )係有關圖2之 本發明故障偵知電路的真理値表。 經濟部智慧財產局員工消費合作社印製 現在，使制動電晶體2 2之閘信號S 〇爲〇 (無閘信 號。即制動電晶體2 2係非導通。）時，係在高耐壓二極 體3 1使反方向電壓加壓所以高耐壓二極體3 1係形成非 導通，因此發光二極體3 3 a係不發光，因而光電晶體 3 3 b也不受光，所以輸出端子3 5之輸出信號S 1係高 電平（1 )之狀態。此係正常狀態。假如使制動電晶體 2 2引起短路故障，則即使制動電晶體2 2之閘信號s 〇 爲0但在尚耐壓二極體3 1係使順方向電壓加壓所以高耐 壓二極體3 1係形成導通，因此發光二極體3 3 a係進行 發光，因而光電晶體3 3 b係進行受光並加以導通，而輸 13 本紙張尺度適用中國國家標準（CNS ) A4規格（210X297公釐） 546909 A7 B7 五、發明説明（11) 出端子3 5之輸出信號S 1係形成低電平。 因此，真理値表係S〇 = 〇而s 1 = 1爲正常，S0 =0而S 1 = 0爲異常。 其次，使制動電晶體2 2之閘信號s 〇爲1 (有閘信 號。即，制動電晶體2 2係導通。）時，則即使制動電晶 體2 2之閘信號S 0爲〇但在高耐壓二極體3 1係使順方 向電壓加壓所以高耐壓二極體3 1係形成導通，因此發光 二極體3 3 a係進行發光，因此光電晶體3 3 b係進行受 光並加以導通’而輸出端子3 5之輸出信號s 1係形成低 電平（0 )。此係正常狀態。 假如使制動電晶體2 2引起開放（〇 p e η )故障， 則即使制動電晶體2 2之閘信號S 〇爲1 ，但在高耐壓二 極體3 1使反方向電壓加壓所以高耐壓二極體3 1係形成 非導通，因此發光二極體3 3 a係不發光，因而光電晶體 3 3 b也不受光’所以輸出端子3 5之輸出信號S 1係在 高電平（1 )狀態。此係異常狀態。 因此，真理値表係S〇=l而S2 = 〇爲正常，S0 =1而S2 = l爲異常。 如此使真理値表記憶於圖1之邏輯電路5放置，使信 號S 〇及S 1之組合形成異常時使故障偵知信號a 〇由邏 輯電路5輸出，以該信號A 〇，進行***於主電路中將開 關A 1、A 2、或A 3立刻呈〇F F狀態。其他，使警報 燈閃亮，或使警報蜂鳴器鳴動爲佳。 如此，本發明係藉由在制動切換元件及制動電阻之連 接點用以連接高耐壓二極體之陰極側且將陽極側連接於低 (請先閱讀背面之注意事項再填寫本頁) -訂 #1. 經濟部智慧財產局員工消費合作社印製 本紙張尺度適用中國國家標準（CNS ) A4規格（210X297公釐） -14- 546909 A7 _____B7_ 五、發明説明（12) (請先閲讀背面之注意事項再填寫本頁) 電壓電源做爲偵知電路，不必使用如先前由大的電力容量 之電阻4 2及4 3所構成串聯連接電路可完成，形成可使 變頻器之低成本化，小空間化，又，電流限制用之電阻也 小容量即足夠，實裝面積也很小形成可完成。又，以光耦 合器一旦進行電氣的絕緣由偵知端子用以取出信號，所以 安全。 取代以上之電晶體2 2，使用切換元件（半導體開關 元件，GTO等）也可係勿庸多贅。 圖3係有關本發明第2實施形態之故障偵知裝置。 圖3中，3 >係故障偵知電路係有關用以偵知制動電 晶體2 2之故障的本發明第2實施形態。其他係相同所以 省略說明。又，故障偵知電路3 >之構成中，光耦合器 3 3之發光二極體3 3 a側也與圖2同樣。另外，光電晶 體3 3 b側，係在低電壓電源L ( 2 4 V )及地線間，使 由電阻3 4 /及光電晶體3 3 b所構成串聯連接電路將其 電阻3 4 >被連接於地線側。又，在該光電晶體3 3 b及 電阻3 4 >之連接點被設有故障偵知輸出端子3 5 >。而 且，使光電晶體3 3 b (集極側）被連接於低電壓電源（ 經濟部智慧財產局員工消費合作社印製 2 4 V )。 於此使光電晶體3 3 b進行受光則光電晶體3 3 b係 進行導通，因此由低電壓電源通過光電晶體3 3 b及電阻 3 4在地線使電流流動，所以輸出端子3 5 >之輸出信號 S 1係由迄此爲止之低電平（0 )變成高電平（1 )。 因此，真理値表，係使制動電晶體2 2之閘信號S 〇 爲0 (無閘信號。即，制動電晶體2 2係非導通。）時則 本紙張尺度適用中國國家標準（CNS ) A4規格（210X297公釐） :15 - " 546909 A7 _____ B7_ 五、發明説明（13) (請先閲讀背面之注意事項再填寫本頁) 發光二極體3 3 a係不發光，因此光電晶體3 3 b也未受 光，所以輸出端子3 5 /之輸出信號S 1係低電平（〇 ) ，此係正常狀態。假如使制動電晶體2 2引起短路故障， 則高耐壓二極體3 1係形成導通，因此發光二極體3 3 a 係進行發光，因而光電晶體3 3 b係進行受光並加以導通 ，而輸出端子3 5 >之輸出信號S 1係形成高電平（1 ) 〇 因此，真理値表係S〇 = 〇而Sl = 〇爲正常，S0 =0而s1=1爲異常。 其次，使制動電晶體2 2之閘信號S 〇爲1 (有閘信 號。即，制動電晶體2 2係導通。）時則高耐壓二極體 3 1係形成導通，因此發光二極體3 3 a係進行發光，因 而光電晶體3 3 b係進行受光並加以導通，而輸出端子 3 5 >之輸出信號S 1係形成高電平（1 )。此係正常狀 態。 假如使制動電晶體2 2引起開放（ο p e η )故障， 則即使制動電晶體2 2之閘信號S 0爲1 ，但在高耐壓二 經濟部智慧財產局員工消費合作社印製 極體3 1使反方向電壓加壓所以高耐壓二極體3 1係形成 非導通，因此光二極體3 3 b係不受光，所以輸出端子 3 5 >之輸出信號S 1係在低電平（〇 )狀態。此係異常 狀態。 因此，真理値表係S0 = 1而S2 = l爲正常，S0 =1而S2=l爲異常。 如此使真理値表記憶於圖1之邏輯電路5放置，使信 號S 0及S 1之組合形成異常時使故障偵知信號a 〇由邏 本紙張尺度適用中國國家標準（CNS ) A4規格（21〇Χ297公釐） 7^6: 546909 Α7 Β7 五、發明説明（14) 輯電路5輸出，以該信號a 〇進行***於主電路中將開關 A 1、A 2、或A 3立刻呈〇F F狀態。其他，使警報燈 閃亮’或使警報蜂鳴器鳴動爲佳。 (請先閲讀背面之注意事項再填寫本頁) Η 4係有關本發明第3實施形態之故障偵知裝置。 圖4中’ 1 1係正極側母線，1 2係負極側母線，2 係制動電阻被***於正極側母線1 1及負極側母線1 2之 間由制動電阻2 1及制動電晶體2 2之串聯電路所構成。 3 "係本發明之故障偵知電路用以偵知制動電晶體2 2之 故障’該故障偵知電路3 〃係在制動電阻2 1及制動電晶 體2 2之連接點ρ被連接。 故障偵知電路3 〃之構成，係使被連接於2 4 V之低 電壓電源L之電阻及被連接成順方向之高耐壓二極體3 1 所構成之串聯連接電路在制動電阻2 1及制動電晶體2 2 之連接點被連接，並在該串聯連接電路將流動電流使變流 器（C Τ ) 4 8進行偵知，C Τ之一端係形成地線側，他 端係形成偵知端子3 5。 其次，對於圖4之故障偵知電路之動作加以說明。 經濟部智慧財產局員工消費合作社印製 使制動電晶體2 2非導通時，在制動電晶體2 2之集 極C係通過電阻2 1使D C母線電壓直接被外加，但在高 耐壓二極體3 1係形成反方向電壓所以使母線電壓藉由高 耐壓二極體3 1被閉塞，在C Τ 4 8係不流動電流。因此 ，輸出端子3 5之輸出信號S 1係低電平（〇 )之狀態。 又.，使制動電晶體2 2導通時，則使制動電晶體2 2 之集極C約形成2 V程度，使高耐壓二極體3 1進行導通 ，在C Τ 4 8係因爲使電流流動，所以在其2次側係使箭 本紙張尺度適用中國國家標準（CNS ) Α4規格（210Χ297公釐） 546909 A7 __ B7 五、發明説明（15) 頭方向之感應電壓進行產生，輸出端子3 5之輸出信號 S 1係形成高電平（1 )。 (請先閲讀背面之注意事項再填寫本頁) 如此，使制動電晶體2 2之閘信號S 〇爲〇 (無閘信 號。即，制動電晶體2 2候非導通。）時係在C T 4 8不 使電流流動，在低電平（0 )之狀態，此係正常狀態。假 如使制動電晶體2 2引起短路故障，則在高耐壓二極體 3 1係使順方向電壓加壓所以高耐壓二極體3 1係形成導 通，在C T 4 8係使電流流動，輸出端子3 5之輸出信號 S 1係形成高電平（1 )。 因此，真理値表係S〇 = 〇而Sl = 〇爲正常，S0 =0而S1=1爲異常。 其次，使制動電晶體2 2之閘信號S 〇爲1 (有閘信 號。即，制動電晶體2 2係導通。）時，則高耐壓二極體 3 1係使順方向電壓加壓所以高耐壓二極體3 1係形成導 通，在C T 4 8係使電流流動，而輸出端子3 5之輸出信 號S 1係形成高電平（1 )。此係正常狀態。 經濟部智慧財產局員工消費合作社印製 假如使制動電晶體2 2引起開放（ο p e η )故障， 則即使制動電晶體2 2之閘信號S 〇爲1 ，但在高耐壓二 極體3 1使反方向電壓加壓所以高耐壓二極體3 1係形成 非導通，因此在C Τ 4 8係使電流流動，而輸出端子3 5 之輸出信號S 1係在低電平（〇 )狀態。此係異常狀態。 因此，真理値表係S〇 = l而Sl = l爲正常，so 二1而S 1 = 0爲異常。 如此使真理値表記憶於圖1之邏輯電路5放置，使信 號S 0及s 1之組合形成異常時使故障偵知信號A 〇由邏 本紙張尺度適用中國國家標準（CNS ) A4規格（2!0X297公釐） :18 _ 546909 A7 B7 五、發明説明（16) (請先閱讀背面之注意事項再填寫本頁) 輯電路5輸出，以該信號A 〇進行***於主電路中將開關 A 1、A 2、或A 3立刻呈〇F F狀態，或使警報燈閃亮 ，或使警報蜂鳴器鳴動爲佳。 【發明之效果】 以上，若依據本發之第1〜第3實施形態，則在制動 切換元件及制動電阻之連接點用以連接高耐壓二極體之陰 極且將陽極側連接低電壓電源之正側做爲偵知電路，所以 不使用如先前由大的電力容量之電阻4 2及4 3所構成串 聯連接電路可完成，使變頻器可形成低成本化，小空間化 ，又電流限制用之電阻也小容量即足夠，實裝面積也很小 可完成。 又，使用如此之偵知電路藉由用以構成變頻器，在變 頻器內之制動切換元件發生故障時，將流入於制動電阻之 電流立刻進行遮斷可防止制動電阻之過熱，而且此係以低 成本，小空間化使變頻器可實現。 【圖式之簡單說明】 經濟部智慧財產局員工消費合作社印製 圖1係被適用有關本發明第1實施形態之故障偵知裝 置的主電路之方塊圖。 圖2係有關本發明第1實施形態之故障偵知裝置。 圖3係有關本發明第2實施形態之故障偵知裝置。 圖4係有關本發明第3實施形態之故障偵知裝置。 圖5係被適用先前之故障偵知裝置的主電路之方塊圖 本紙張尺度適用中國國家標準（CNS ) A4規格（210X297公釐） -19 - 546909 A7 B7 五、發明説明（17) 圖6係先前之故障偵知裝置。 (請先閲讀背面之注意事項再填寫本頁) 圖7係切換元件之控制信號及故障偵知電路之輸出信 號的真理値表。 【元件編號之說明】 11…直流電壓正極側母線， 1 2直流電壓負極側母線， 2…制動電路， 3、3 /、3 〃…故障偵知電路， 5…邏輯電路， 21…制動電阻， 2 2…制動電晶體， 3 2、3 4…電阻， 3 3…光親合器， 3 3 a…發光二極體， 3 3 b…光電晶體， 3 4、3 4 '··電阻， 3 5、3 5 /、3 5 〃…偵知輸出端子， 5 1…3相電源，5 2…變換器， 經濟部智慧財產局員工消費合作社印製 5 2 a…被電橋連接之二極體， 5 2 b… 平滑 電 容 器， 5 3 …變 頻器 5 4 …馬 達， S 0 …控 制切 換 元 件之閘（控制）信號 S 1 …偵 知輸 出 信 號， A 0 …故 障信 號 〇 本紙張尺度適用中國國家標準（CNS ) A4規格（210X297公釐） -20 -546909 A7 _____B7_ V. Description of the invention (1) [Technical field to which the invention belongs] (Please read the precautions on the back before filling out this page) The present invention relates to the use of brake transistors, etc. used to detect general inverters. The failure of the switching element is used to prevent abnormal heating of the inverter and braking resistor. [Previous technology] Generally, inverters for general use are equipped with braking resistors in order to absorb the energy that is returned by the motor during braking during regenerative braking and regenerative braking. Short-circuit faults in the switching elements that cause the current to flow through the braking resistor In this case, the braking resistor will cause abnormal heating, and in the worst case, the braking resistor will be burnt out, and the peripheral parts may also have secondary damage. As a preventive device, such as installing a thermal fuse in series with the braking resistor, the thermal fuse is cut off when the short circuit of the switching element fails. The braking resistor is used to block the current. And the temperature rise speed of the braking resistor makes the temperature fuse operation too late before the protective device can function. Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs Therefore, there is a method for monitoring the voltage across the braking resistor at the braking resistor to detect the time of the flowing current. FIG. 5 is a block diagram of a main circuit to which a fault detection device is applied. In FIG. 5, 51 is a 3-phase power supply, and an inverter 52 is connected here. The inverter 5 2 is composed of a diode 5 2 a and a smoothing capacitor 5 2 b connected to a bridge (not shown), and an AC-DC converted DC voltage is output on the output side of the capacitor 5 2. Between the positive-side bus bar 1 1 and the negative-side bus bar 12. 5 The 3 series inverter converts the DC voltage into 3 intersects. The paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) -4-546909 A7 B7 V. Description of the invention (2) The current is A control switching element for bridge connection (not shown) has an induction motor connected to the output side of the inverter section 53. In this main circuit, the 2 series brake circuit is inserted into the positive side bus (please read the precautions on the back before filling this page) 1 1 and the negative side bus 1 2, which is composed of the braking resistor 21 and the braking current. The crystal 22 is composed of a series circuit. Moreover, the 4 series previous fault detection circuit is used to detect the failure of the brake transistor 2 2 and is connected to both ends of the brake resistor 2 1. The failure detection circuit 4 is described later. The 5 series logic circuit is formed by the brake signal S 0 of the brake transistor 22 and the output signal S 2 of the fault detection circuit 4 and is used to output the fault signal A 0 when there is a predetermined relationship. Fig. 6 is a diagram showing an example of a specific circuit configuration of a conventional fault detection circuit. In Fig. 6, 11 series of positive side buses, 12 series of negative side buses, and 2 series of braking circuits are inserted between the positive side bus 11 and the negative side bus 12 and connected in series by a braking resistor 21 and a braking transistor 22. Circuit. 4 is a previous fault detection circuit for detecting the failure of the brake transistor 2 2. The fault detection circuit 4 is connected to both ends of the braking resistor 21. The structure of the fault detection circuit 4 printed by the employee's consumer cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs is a resistor 4 1 connected in parallel to the braking resistor 21 and a series connection circuit composed of resistors 42 and 43 at the resistor 41 Are connected in parallel. Further, in the resistor 43, a series connection circuit in which the anodes composed of the voltage-stabilizing diodes 4 4 and the light-emitting diodes 4 5 a are butted against each other is connected in parallel. In addition, between the low-voltage power supply (2 4 V) and the ground wire, a series connection circuit composed of a resistor 46 and a photoelectric crystal 4 5 b is used, and the emitter E of the photoelectric crystal 4 5 b is used as the ground wire side and connection. On the collector side, a fault detection output terminal 4 7 is provided. This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) -5-546909 A7 _B7 V. Description of the invention (3) (Please read the back first (Please fill out this page again). In addition, the photoelectric crystal 4 5 b and the light-emitting diode 4 5 a together constitute the optical coupler 4 5, and the photo-crystal 4 5 b is used to receive light and the light-emitting diode 4 5 a is configured to conduct electricity. . The stabilized diode 4 4 is based on its stabilized voltage as a reference and an interruption is generated when the voltage is higher than this to make the light-emitting diode 4 5 a emit light. Therefore, usually, the interference is caused by the interference below the stabilized voltage. In order to stabilize the light emission operation, erroneous light emission does not occur. The resistance 4 1 is a resistance that prevents the light-emitting diode 4 5 a from emitting light and biases the current due to the leakage current of the brake transistor 22 when the braking resistor 21 is not connected. Next, the operation of the previous fault detection circuit 4 of Fig. 6 will be described. The voltage across the braking resistor 21 is to divide the voltage across the resistor 41 into a series connection circuit composed of resistors 4 2 and 4 3 and divide the voltage across the resistor 4 3 to a certain set voltage or higher to stabilize the voltage. Diode 4 4 generates a penetrating current and flows in the light-emitting diode 4 5 a, so that the light-emitting diode prints 4 5 a to emit light. When the light-emission causes the photo-crystal 4 5 b to receive light, the photo-crystal 4 5 b is turned on. Therefore, a current is passed between the ground by the low-voltage power source through the resistor 46 and the phototransistor 4 5 b. Therefore, when the photo-crystal 4 5 b is non-conducting, the output signal 5 2 of the output terminal 47 is at a high level or after the photo-crystal 4 5 b is turned on, it becomes a low level. FIG. 7 is a truth table of the brake signal 22 and the output of the fault detection circuit 4, and FIG. 7 (a) is a truth table of the previous fault detection circuit of FIG. 6. Now, make the brake signal S 0 of the brake transistor 2 2 0. (The size of the paper without the brake applies the Chinese National Standard (CNS) A4 specification (210X297 mm). 701-546909 A7 ___ B7. V. Description of the invention ( 4) (Please read the precautions on the back before filling this page). That is, when the brake transistor 2_ 2 is non-conducting), the voltage across the braking resistor 2 1 is zero, so the voltage regulator diode 4 4 series No breakdown, so the light-emitting diode 4 5 a does not emit light, and thus the photo-crystal 4 5 b is not affected by the light, so the output signal S 2 of the output terminal 47 is at a high level (1). This is normal. If the brake transistor 22 is short-circuited, the brake signal S 2 of the brake transistor 22 will be zero, but the voltage across the brake resistor 21 will cause the voltage across the line to be generated. The pole body 44 is broken down to make the light emitting diode body 4 5 a emit light, so the photo-crystal 4 5 b is turned on and the output signal S 2 of the output terminal 47 is reduced to the ground level (0). Therefore, the truth is that S 0 = 0 makes S 2 = 1 a normal state, and S 0 = 0 makes S 2 = 0 an abnormal state. Next, when the brake signal S 0 of the brake transistor 22 is set to 1 (with a brake signal. That is, the brake transistor 2 2 is in an on state), the voltage across the brake resistor 21 generates an approximately line-to-line voltage, so The voltage-stabilizing diode 4 4 is made to break down and the light-emitting diode 4 5 a is turned on. Therefore, the phototransistor 4 5 b is turned on and the output signal S 2 of the output terminal 47 is reduced to the ground level ( 0). This is normal. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. If the brake transistor 22 is opened, even if the brake signal S 0 of the brake transistor 2 2 is 1, the two terminals of the brake resistor 21 are zero and stable. The pressure diode 4 4 does not penetrate, so the light-emitting diode 4 5 a does not emit light, so the photo-crystal 4 5 b is not affected by light, so the output signal S 2 of the output terminal 4 7 is at a high level (1 ) 'S status. This is an abnormal state. Therefore, the truth is that S 〇 = 〇 makes S 2 20 be normal, and this paper size applies the Chinese National Standard (CNS) A4 specification (210X 297 mm) Zj. 546909 Α7 Β7 V. Description of the invention (5) S 0 = 1 makes S 2 = 1 an abnormal state. (Read the precautions on the back before you fill in this page.) Make such a truth table memorize in logic circuit 5 of Figure 5 and place the fault detection signal A when the combination of signals S 0 and S 2 is abnormal. Logic The output of circuit 5 is the state of switch A 1, A 2 or A 3 V. 0 FF which will be inserted in the main circuit with this signal A. [Problem to be solved by the invention] So, if it is based on the previous circuit, it can be used to detect The previous stage of the brake transistor 2 2. However, the previous circuit was used to detect the failure of the brake transistor 2 2 and to monitor the voltage across the brake resistor 21, so when the brake transistor is turned on The voltage applied to both ends of the braking resistor 21 is to increase the DC bus voltage of the inverter. This is a very high voltage, so a series connection circuit composed of resistors 4 2 and 4 3 needs a large amount of power. The resistance of the capacity. This is the bottleneck of the low cost and miniaturization of the inverter. The Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economics printed on the previous device, because the voltage for monitoring is very high, so the current is limited. The resistor must also be used as a very large power, and the mounting area is also large. The present invention is intended to solve these problems, so a resistor with a large electric capacity that is not necessary for the fault detection circuit is provided, and the frequency converter can be reduced in cost. Small space, and the current-limiting resistance is also sufficient with a small capacity, and the mounting area can be reduced. [Solutions to Problem] This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) -8 · 546909 at B7 V. Description of the invention (6) C. Read the notes on the back 4¾ Write this page} The present invention is to solve these problems, if the brake switching according to item 1 of the scope of patent application is applied The invention of the failure detection circuit of the element enables the series connection circuit of the braking resistor and the brake switching element to be connected between the DC bus of the input side of the inverter and is used to form the fault detection circuit of the switching element of the braking circuit. Is characterized in that the connection points of the brake switching element and the braking resistor in the aforementioned braking circuit are used to connect the cathode side of the high voltage diode The anode side is connected to the positive side of the low-voltage power supply, and the aforementioned high-withstand voltage diode is used to detect the presence or absence of a flowing current and detect the brake switching element of the inverter. The invention described in the second scope of the patent application It is the fault detection circuit described in item 1 of the scope of the patent application, which is characterized by the logic combination of the presence or absence of the control signal of the brake switching element and the detection gas number of the foregoing detection circuit to determine the aforementioned The failure of the brake switching element. The Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs printed the invention described in the third patent application scope, which is the fault detection circuit described in the second patent application scope, which is characterized by: The detection circuit is provided with a photocoupler for detecting a light-emitting diode and the light-emitting of the light-emitting diode, and is constituted by a conducting photoelectric crystal, and the light-emitting diode is on the anode side of the high-voltage withstand diode And the positive side power supply is connected in a forward direction, and the high voltage withstand diode will output a current through a photocoupler. The invention described in item 4 of the scope of patent application is the fault detection circuit described in item 3 of the scope of patent application, which is characterized in that the aforementioned optoelectronic crystal is connected by a resistor between the positive power source side and the ground, and The detection output terminal of the aforementioned detection circuit for the photoelectric crystal, A) is set on the positive power supply side through a resistor, or B) is set on the ground line side through a resistor 'A) is set on the original paper and the Chinese national standard is applied ( CNS) A4 specification (210X 297 mm) -9- 546909 A7 __B7 _ 5. Description of the invention (8) Low cost and small space. (Please read the precautions on the back before filling out this page) In addition, the invention of the inverter described in item 6 of the scope of patent application 'has fault detection as described in any one of the scope of patent applications 1 to 5' In the inverter of the circuit, when the detection result of the detection circuit is judged to be a failure of the brake switching element, a device for immediately interrupting the current flowing into the braking resistor is provided. This is used to detect the failure of the brake switching element in the inverter and immediately block it to prevent overheating of the braking resistor. The safe inverter can be manufactured with low cost and small space. [Embodiment of Invention] Printed by the Consumer Cooperative of Intellectual Property Bureau, Ministry of Economic Affairs Figure 1 is a block diagram of the main circuit of a fault detection device to which the first embodiment of the present invention is applied. In Fig. 1, 5 1 is a 3-phase power supply, and an inverter 52 is connected thereto. The inverter 5 2 is composed of a diode 5 2 a and a flat sliding container 5 2 b connected by a bridge (not shown), and an AC-DC converted DC voltage is output on the output side of the inverter 5 2. It is output between the positive-side bus 11 and the negative-side bus 12. 5 3 series inverter section converts this DC voltage into 3-phase AC, has a control switching element connected by a bridge (not shown), and an induction motor is connected to the output side of the inverter section 5 3 5 4. In such a main circuit, a 2 series braking circuit is inserted between the positive side bus 11 and the negative side bus 12, which is composed of a series circuit of a braking resistor 21 and a braking transistor 22. Moreover, 3 is a fault detection circuit related to the present invention for detecting the failure of the brake transistor 22, and is connected at the connection point P of the brake resistor 21 and the brake transistor 22.2. For this fault detection paper size, the Chinese National Standard (CNS) A4 specification (21〇 > < 297 mm) 7γ \ Z " 546909 A7 _ B7 _ V. Description of the invention (9) (Please read the Please fill in this page again for details. The 5 series logic circuit is used to output the fault signal A 0 when the logic combination of the brake signal S 2 of the brake transistor 2 and the output signal S 1 of the fault detection circuit 3 has a predetermined relationship, and use the fault signal A 0 to make Circuit protection is performed. FIG. 2 is a fault detection device according to the first embodiment of the present invention. In Fig. 2, 1 1 is a positive-side bus, 12 is a negative-side bus' 2 is a braking resistor is inserted between the positive-side bus 11 and the negative-side bus 12 by a braking resistor 2 1 and a braking transistor 2 2 Consists of a series circuit. 3 is a fault detection circuit of the present invention for detecting the failure of the brake transistor 22, and the fault detection circuit 3 is connected at the connection point P of the brake resistor 21 and the brake transistor 22. The structure of the fault detection circuit 3 is a low-voltage power supply L of 2 4 V, which makes the light-emitting diodes 3 3 a and resistors 3 2 connected in the forward direction and the high-voltage-resistant diodes 3 connected in the forward direction. The series connection circuit composed of 1 is connected at the connection point of the braking resistor 21 and the braking transistor 22. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. In addition, a low-voltage power supply L (2 4 V) and ground are connected by a series connection circuit composed of a resistor 34 and a photoelectric crystal 3 3 b to make the photoelectric crystal 3 3 The emitter side E of b is connected as the ground side. On its collector side C, a fault detection output terminal 35 is set. In addition, the photoelectric crystal 3 3 b and the light-emitting diode 3 3 a together constitute the photocoupler 3 3, and the photo-crystal 3 3 b is used to receive light and the light-emitting diode 3 3 a is configured to conduct electricity. . Next, the operation of the fault detection circuit of FIG. 2 will be described. When the brake transistor 22 is made non-conducting, the DC voltage of the DC bus is directly applied to the collector C of the brake transistor 22 through the resistor 21, so the Chinese national standard (CNS) A4 specification (210X297) is applied in this paper. H -12-" " " 546909 A7 _____B7_ V. Description of the invention ((Please read the precautions on the back before filling out this page) High-withstand voltage diode 3 1 Series forms the reverse direction voltage, which makes the DC bus voltage borrow The high-voltage withstand diode 31 is adjusted. Therefore, the light-emitting diode 3 3 a does not emit light, so the photo-crystal 3 3 b is not turned on, and the output signal S 2 1 of the output terminal 4 7 is high-level ( 1). When the brake transistor 2 2 is turned on, the collector C of the brake transistor 2 2 is formed to about 2 V, and the high withstand voltage diode 3 1 is turned on, and the resistor 3 2 is turned on. In order to cause the light-emitting diode 3 3 a to emit light, the light-emitting diode 3 3 b receives light, and the photo-crystal 3 3 b system is turned on. Therefore, a low-voltage power source passes the resistor 34 and the photo-crystal 3 3 b. A current flows between the ground wires. As a result, the output signal S 1 of the output terminal 35 is at A high level or a low level (0) is formed after the optoelectronic crystal 3 3 b is turned on. Figure 7 shows the truth of the brake signal S 0 of the brake transistor 2 2 and the output signal S 1 of the fault detection circuit 4, Fig. 7 (b) is a truth table related to the fault detection circuit of the present invention shown in Fig. 2. It is printed by the Consumer Cooperative of Intellectual Property Bureau of the Ministry of Economic Affairs. Now, the brake signal S 2 of the brake transistor 22 is 〇 That is, the brake transistor 2 2 is non-conducting.) When it is connected to the high withstand voltage diode 3 1 to pressurize the voltage in the reverse direction, the high withstand voltage diode 3 1 is non-conducting, so the light emitting diode 3 3 a does not emit light, so the photoelectric crystal 3 3 b does not receive light, so the output signal S 1 of output terminal 3 5 is in a high-level (1) state. This is a normal state. If the brake transistor 2 2 causes a short circuit If the brake signal s 0 of the brake transistor 22 is 0, the forward voltage is applied to the high voltage diode 3 1 so that the high voltage diode 3 1 is turned on, so the light emitting diode 2 is turned on. The body 3 3 a emits light, so the photo-crystal 3 3 b receives and conducts light, and 13 papers are lost. The scale applies to the Chinese National Standard (CNS) A4 specification (210X297 mm) 546909 A7 B7 V. Description of the invention (11) The output signal S 1 of the terminal 3 5 forms a low level. Therefore, the truth is expressed as S 0 = 〇 And s 1 = 1 is normal, S0 = 0 and S 1 = 0 is abnormal. Second, the brake signal s 0 of the brake transistor 22 is set to 1 (with brake signal. That is, the brake transistor 22 is turned on. ), Even if the brake signal S 0 of the brake transistor 2 2 is 0, the forward voltage is applied to the high voltage diode 3 1 series, so the high voltage diode 3 1 series is turned on, so the light emitting diode 2 is turned on. The polar body 3 3 a emits light, so the photo-crystal 3 3 b receives light and turns it on, and the output signal s 1 of the output terminal 35 forms a low level (0). This is normal. If the brake transistor 22 is caused to open (ope η), even if the brake signal S 0 of the brake transistor 22 is 1, but the high-voltage diode 31 is pressurized in the reverse direction, the voltage is high. The piezodiode 3 1 is non-conducting, so the light-emitting diode 3 3 a does not emit light, so the optoelectronic crystal 3 3 b does not receive light. Therefore, the output signal S 1 of the output terminal 3 5 is at a high level (1 )status. This is an abnormal state. Therefore, the truth is that S = 1 and S2 = 0 are normal, S0 = 1 and S2 = 1 are abnormal. In this way, the truth table is memorized and placed in the logic circuit 5 in FIG. 1, and when the combination of the signals S 0 and S 1 forms an abnormality, the fault detection signal a 〇 is output by the logic circuit 5, and the signal A 〇 is inserted into the main In the circuit, the switches A 1, A 2, or A 3 are in the 0FF state immediately. Otherwise, it is better to make the alarm light flash or make the alarm buzzer sound. In this way, the present invention uses the connection point of the brake switching element and the brake resistor to connect the cathode side of the high voltage diode and the anode side to low (please read the precautions on the back before filling this page)- Order # 1. Printed by the Consumers' Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs This paper is printed in accordance with Chinese National Standard (CNS) A4 (210X297 mm) -14- 546909 A7 _____B7_ V. Description of the Invention (12) (Please read the first Please fill in this page again.) The voltage power supply is used as the detection circuit, and it is not necessary to use a series connection circuit composed of large power capacity resistors 4 2 and 4 3, which can reduce the cost and reduce the frequency of the inverter. Space-saving, and the current-limiting resistor is also small enough, and the mounting area is also small. In addition, since the photocoupler is electrically insulated once the detection terminal is used to take out signals, it is safe. Instead of the above transistors 22, the use of switching elements (semiconductor switching elements, GTO, etc.) can be unnecessary. Fig. 3 shows a fault detection device according to a second embodiment of the present invention. In Fig. 3, 3 > fault detection circuit relates to a second embodiment of the present invention for detecting a failure of the brake transistor 22. The other parts are the same, so the description is omitted. In the configuration of the fault detection circuit 3 >, the light emitting diode 3 3 a side of the photocoupler 33 is also the same as that shown in FIG. 2. In addition, the photoelectric crystal 3 3 b side is connected between the low-voltage power supply L (24 V) and the ground. A series connection circuit composed of the resistor 3 4 / and the photoelectric crystal 3 3 b has its resistance 3 4 > Connected to the ground side. Further, a failure detection output terminal 3 5 > is provided at a connection point of the photo-crystal 3 3 b and the resistor 3 4 >. Furthermore, the optoelectronic crystal 3 3 b (collector side) was connected to a low-voltage power source (printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs, 2 4 V). When the photo-crystal 3 3 b receives light, the photo-crystal 3 3 b is turned on. Therefore, a low-voltage power source causes a current to flow through the photo-crystal 3 3 b and the resistor 3 4 on the ground, so the output terminal 3 5 > The output signal S 1 is changed from the low level (0) to the high level (1) so far. Therefore, the truth is that when the brake signal S 2 of the brake transistor 22 is 0 (no brake signal. That is, the brake transistor 2 2 is non-conducting.), The Chinese standard (CNS) A4 applies to this paper standard. Specifications (210X297 mm): 15-" 546909 A7 _____ B7_ V. Description of the invention (13) (Please read the precautions on the back before filling out this page) Light-emitting diodes 3 3 A does not emit light, so the photoelectric crystal 3 3 b also does not receive light, so the output signal S 1 of output terminal 3 5 / is a low level (0), which is a normal state. If the brake transistor 22 causes a short-circuit fault, the high-voltage withstand diode 3 1 system is turned on, so the light-emitting diode 3 3 a system emits light, so the photo-crystal 3 3 b system receives light and conducts it, and The output signal S 1 of the output terminal 3 5 is high (1). Therefore, the truth table is S = 0 and Sl = 0 is normal, S0 = 0 and s1 = 1 is abnormal. Next, when the brake signal S 0 of the brake transistor 22 is set to 1 (there is a brake signal. That is, the brake transistor 22 is turned on.), Then the high breakdown voltage diode 3 1 is turned on, so the light emitting diode is turned on. Since 3 3 a emits light, the photo-crystal 3 3 b receives and conducts light, and the output signal S 1 of the output terminal 3 5 > forms a high level (1). This is normal. If the brake transistor 22 is caused to open (ο pe η) fault, even if the brake signal S 0 of the brake transistor 22 is 1, the polar body 3 will be printed at the Consumers ’Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs of the Ministry of High Voltage II. 1 pressurizes the voltage in the reverse direction, so the high withstand voltage diode 3 1 is non-conducting, so the photodiode 3 3 b is not receiving light, so the output signal S 1 of the output terminal 3 5 > is at a low level ( 〇) status. This is an abnormal state. Therefore, the truth is that S0 = 1 and S2 = l are normal, S0 = 1 and S2 = l are abnormal. In this way, the truth table is memorized and placed in the logic circuit 5 in FIG. 1, so that when the combination of the signals S 0 and S 1 forms an abnormality, the fault detection signal a 〇 applies the Chinese National Standard (CNS) A4 specification (21) 〇 × 297 mm) 7 ^ 6: 546909 Α7 Β7 V. Description of the invention (14) The output of the circuit 5 is inserted into the main circuit with the signal a 〇 and the switch A 1, A 2, or A 3 is immediately FF status. Otherwise, it is better to make the alarm lamp blink 'or to make the alarm buzzer sound. (Please read the precautions on the back before filling out this page) Η 4 is a fault detection device related to the third embodiment of the present invention. In Figure 4, '1 1 series positive bus, 1 2 series negative bus, and 2 series braking resistors are inserted between the positive bus 1 1 and the negative bus 12 1 by a braking resistor 2 1 and a braking transistor 2 2 Consists of a series circuit. 3 " The fault detection circuit of the present invention is used to detect the failure of the brake transistor 2 2 '. The fault detection circuit 3 is connected at the connection point ρ of the brake resistor 21 and the brake transistor 22. The fault detection circuit 3 is composed of a resistor connected to a low-voltage power supply L of 2 4 V and a high-voltage withstand diode 3 1 connected in a forward direction. The braking resistor 2 1 is connected in series. And the connection point of the brake transistor 2 2 are connected, and the current flowing through the series connection circuit makes the current transformer (C T) 4 8 detect. One end of the C T forms the ground side, and the other end forms the detection side.知 Terminal 3 5. Next, the operation of the fault detection circuit of FIG. 4 will be described. When the consumer cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs makes the brake transistor 2 2 non-conducting, the DC voltage of the DC bus is directly applied to the collector C of the brake transistor 2 2 through the resistor 21, but at the high withstand voltage diode The body 3 1 series forms a reverse voltage so that the bus voltage is blocked by the high withstand voltage diode 3 1 and no current flows in the C T 4 8 series. Therefore, the output signal S 1 of the output terminal 35 is in a low-level (0) state. In addition, when the brake transistor 2 2 is turned on, the collector C of the brake transistor 2 2 is formed to about 2 V, and the high-voltage withstand diode 31 is turned on. Flow, so on its secondary side, the paper size of the arrow pad applies the Chinese National Standard (CNS) A4 specification (210 × 297 mm) 546909 A7 __ B7 V. Description of the invention (15) The induced voltage in the direction of the head is generated, and the output terminal 3 The output signal S 1 of 5 forms a high level (1). (Please read the precautions on the back before filling this page) So, make the brake signal S 2 of the brake transistor 2 2 0 (no brake signal. That is, the brake transistor 2 2 is non-conducting.) Is at CT 4 8 does not make current flow, in a low level (0) state, this is a normal state. If the brake transistor 22 causes a short circuit fault, the high-voltage diode 3 1 series will pressurize the forward voltage, so the high-voltage diode 3 1 series will be turned on, and the CT 4 8 series will cause current to flow. The output signal S 1 of the output terminal 35 is set to a high level (1). Therefore, the truth table is that S = 0 and Sl = 0 are normal, S0 = 0 and S1 = 1 are abnormal. Next, if the brake signal S o of the brake transistor 22 is set to 1 (the brake signal is present. That is, the brake transistor 22 is turned on.), Then the high withstand voltage diode 31 will increase the voltage in the forward direction. The high-withstand voltage diode 3 1 is turned on, and a current is caused to flow in the CT 4 8, and the output signal S 1 of the output terminal 35 is set to a high level (1). This is normal. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs, if the brake transistor 22 is caused to open (ο pe η), even if the brake signal S 0 of the brake transistor 2 2 is 1, but at the high withstand voltage diode 3 1 pressurizes the voltage in the reverse direction, so the high withstand voltage diode 3 1 is non-conducting, so current flows in C T 4 8 and the output signal S 1 of output terminal 3 5 is at a low level (0). status. This is an abnormal state. Therefore, the truth table is that S = 1 and Sl = 1 are normal, so 2 = 1 and S 1 = 0 are abnormal. In this way, the truth table is memorized and placed in the logic circuit 5 in FIG. 1, so that when the combination of the signals S 0 and s 1 forms an abnormality, the fault detection signal A 〇 is applied to the Chinese paper standard (CNS) A4 specification (2) ! 0X297mm): 18 _ 546909 A7 B7 5. Description of the invention (16) (Please read the precautions on the back before filling this page) Edit circuit 5 output, insert this signal A 〇 into the main circuit and switch A 1, A 2, or A 3 immediately assume 0FF state, or make the alarm lamp flash, or make the alarm buzzer sound. [Effects of the Invention] As described above, according to the first to third embodiments of the present invention, the connection point of the brake switching element and the brake resistor is used to connect the cathode of a high voltage withstand diode and connect the anode side to a low voltage power source. The positive side is used as the detection circuit, so it can be completed without using a series connection circuit composed of large power capacity resistors 4 2 and 4 3, so that the inverter can be reduced in cost, space, and current limit. The resistance used is also small enough, and the mounting area is also small to complete. In addition, by using such a detection circuit to constitute an inverter, when the brake switching element in the inverter fails, the current flowing into the braking resistor is immediately blocked to prevent the braking resistor from overheating. Low cost and small space make the inverter realizable. [Brief description of the diagram] Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs Figure 1 is a block diagram of the main circuit to which the fault detection device according to the first embodiment of the present invention is applied. FIG. 2 is a fault detection device according to the first embodiment of the present invention. Fig. 3 shows a fault detection device according to a second embodiment of the present invention. Fig. 4 shows a fault detection device according to a third embodiment of the present invention. Figure 5 is a block diagram of the main circuit of the previous fault detection device. The paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) -19-546909 A7 B7 V. Description of the invention (17) Figure 6 Series Previous fault detection device. (Please read the precautions on the back before filling this page.) Figure 7 is the truth table of the control signal of the switching element and the output signal of the fault detection circuit. [Explanation of component numbers] 11 ... DC voltage positive side bus, 1 2 DC voltage negative side bus, 2 ... brake circuit, 3, 3 /, 3 〃 ... fault detection circuit, 5 ... logic circuit, 21 ... brake resistor, 2 2 ... brake transistor, 3 2, 3 4 ... resistor, 3 3 ... photocoupler, 3 3 a ... light emitting diode, 3 3 b ... photoelectric crystal, 3 4, 3 4 '· resistance, 3 5, 3 5 /, 3 5 〃 ... detection output terminal, 5 1… 3-phase power supply, 5 2… inverter, printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 5 2 a… diode connected by the bridge , 5 2 b… smoothing capacitor, 5 3… inverter 5 4… motor, S 0… control (switching) signal S 1 of control switching element, detection output signal, A 0… fault signal Standard (CNS) A4 size (210X297 mm) -20-