M324920 八、新型說明： f新型所屬之技術領域】 本創作係關於一種太陽能電力控制裝置，尤指一種自 動判斷光源充足時即對電池充電’光源不足時則可依據電 池電力是否充足而以電池提供電力或由電源供應器提供電 力之太陽能電力控制裝置。 【先前技術】 由於石油能源逐漸㈣，引起世人開發替代能源的这 切感’在所有替代能源中，太陽能被視為經濟且符合環保 概念’因此目前太陽能的運用已逐漸引起重視。太陽能最 基本的運用方式，係由太陽能板收集太陽能後直接使用其 熱此，或轉換為電力供後端使用。 /然由於太陽並非一整天均會高掛於天上，故當太陽下 山後，仰賴太陽能作為電力來源之裝置即無法再行運作， 此情況對於-般太陽能裝置之使用遂造成限制；以照明裝 =例，由於白天時通常毋需開啟照明裝i，而黑夜來臨 沒須開啟㈣裝置’因此此情況恰與太陽之運行相 造成照明裝置無法應用太陽能作為電力來源。 陽炉=3可知，目前尚缺乏有效的電力管理機制，使太 的運料更有效率，以進-步提供更多的應用。 【新型内容】 的在提供一種太陽能電力控制 為此，本創作之主要目 M324920 裝置’其可自動判斷光源充足時即對電池充電，光源不足 時則可依據電池電力是否充足而以電池提供電力或由電源 供應器提供電力。 為達成前述目的所採取之主要技術手段係令前述太陽 能電力控制裝置包括： 一太陽能模組，係包括一太陽能板、一電壓轉換電路 以及至少一電池’其中該太陽能板係供接收光能並轉換成 直流電輸出’另該電壓轉換電路係連接該太陽能板，以將 太陽能板輸出之直流電變壓，而該電池係連接該電壓轉換 電路’以儲蓄經變壓後的直流電； 一光強度偵測單元，係連接該太陽能板，以判斷由太 陽能板接收之光能是否充足； 一開關單元，係連接該光強度偵測單元且由其控制切 換，又該開關單元尚包括兩切換開關，其中一切換開關係 連接於该太陽能板和電壓轉換電路之間，以依據太陽能板 接收之光能是否充足而切換太陽能板和電壓轉換電路是否 建立連線，另一切換開關係連接於該電池與一負載之間， 以依據太陽能板接收之光能是否充足而切換是否由電池提 供電力予負載； -電源選擇電路，係連接該電池、一外部電源以及負 載，以量測電池電力是否充足以及控制是否建立外部電源 與負載之間的連線； 一過放限制電路，係連接該電池以偵測電池之電力是 否充足，又該過放限制電路尚包括一限制開關，該限制開 M324920 關係連接於開關單元之切換開關與負載之間，以依據電池 電力是否充足而切換是否由電池提供 利用上述技術手段，即可在安全有效率的狀況下自動 地調整使用太陽能，於陽光充^時對電池充電但不對負載 供電，俟天色漸暗後轉由電池對負載供電，如電池電力不 足，則改由外部電源對負載供電；如電池電力充足，即自 動切斷外部電源，而由電池對負載供電。 【實施方式】 關於本創作之一較佳實施例，請參閲第一圖所示，包 括-太，能模組（1〇)、一光強度㈣單元（2〇)、 -開關單元（3 Q )、-電源選擇電路（4 ◦)以及一過 放限制電路（5 0 )。 明進-步參閱第二圖所示，上述太陽能模組㈠〇 ) 係包括： 9板（1 1 )，係供接收光能並轉換成直流電 輸出； -電壓轉換電路（2 2 )，係連接該太陽能板（1 1 )， 以將太陽能板輸出之直流電降壓，又該電壓轉換電路（1 2 )可為-直流/直流轉換電路或一脈波寬度調變（Μα W^idth Modulation，簡稱pffM)式電壓轉換器；另請參閲 第二圖所不，於本實施例中該電壓轉換電路（1 2 )係為 -直流/直流轉換電路’其採取.Qff充電法，可達快速 充電、避免過充之目的；又若該電壓轉換電路（1 2)係 M324920 採用PWM式電壓轉換器，則可藉由其具有的最大功率追縱 功能，而以最大功率進行電壓之轉換；及 至J 一電池（1 3 )，係連接該電壓轉換電路（丄2 )， 以儲蓄經降壓後的直流電。 上述光強度谓測單元（20)係連接該太陽能板（1 1);請配合第二圖所示’於本實施例中，該光強度偵測 早疋（2 0 )係藉由谓測該太陽能板（丄工）所輸出之直 流電電壓是否大於-電壓值（例如6 2V)，以判斷由太陽 能板（11)純之光能是否充^，且該光強度 (2 0 )係包括： 了第-稽納二極體ZD1，其正極係連接該太陽能板（ι 丄j ， 第t a日體Q1’其基極係連接該第一稽納二極體則 之負極；及 1二電晶體Q2，其基極係連接該第—電晶體qi的 二：極則連接該第-電晶體Q1的集極； 而传望至卜光線充足，該第—稽納二極體ZD1係導通，從 而使弟：電晶體Q1和第二電晶體Q2導通。 上述開關單元（3 η、在、由上 〇 ) Η Λ # )係連接該光強度偵測單元（2 U)且由其控制切換；請配 it ( ^ π 第一與二圖所示，該開關單 (3 0)係-繼電器，其包括： 一激磁線圈（3 1 )，係3查姑# 〇 )之笛—士 B 糸連接該光強度偵測單元（2 U )之第一電晶體Q2的集極； 一第一磁感應開關（ )’係連接該於該太陽能模 M324920 組（1 Ο )中的太陽能板（1 i )和電壓轉換電路（丄2 ) 之間，其中該第-磁感應開@ (3 2)之共同節點係連接 該電壓轉換電路（1 2 )，而第一磁感應開關（3 2 )之 常開節點則連接該太陽能板（1 i 及 一第二磁感應開關（33)，係連接該電池（13)， 其中該第二磁感應開關（3 3 )之共同節點係連接該電池 (1 3 )’而該第二磁感應開關（3 3 )之常閉節點則連 接一負載（6 0 )，於本實施例中，該負載（6 〇 )係包 含一驅動電路（6 1 )與一高強度氣體放電（以抽一 intensity discharge，簡稱 HID)燈（6 2 )； 若該第二電晶體Q2導通，將使該激磁線圈（3工） 激磁，令該兩磁感應開關（3 2 ) ( 3 3 )由常閉節點切 換至常開節點，使太陽能板（1 1 )和電壓轉換電路（1 2 )連線，因此該太陽能板（1丄）輸出之直流電將輸入 該電壓轉換電路（12)，並進而對該電池（13)充電· 當第二電晶體Q2不導通時，該激磁線圈（3丄）不 再激磁，因此該兩磁感應開關（3 2 ) ( 3 3 )係白& 、曰吊開 節點切換至常閉節點，以切斷該太陽能板（丄i )和電壓 轉換電路（1 2 )之間的連線，並令電池（1 3 )與負載 (6 0 )連線。 上述電源選擇電路（4 0 )係連接該電池（1 3 )、 一外部電源（7 ◦)及負載（6 0 )，以量測電池（丄3〕 之電力是否充足，並控制是否建立外部電源（7 〇 )與負 載（6 0 )之間的連線；於本實施例中，該電源選擇電路 M324920 (4 Ο )係包括： 電阻R1，其一端係連接該太陽能模組（1 〇 )的電 池（1 3 ) —端； 第二稽納二極體ZD2，其正極係連接該電阻R1之另 另端，因此該第二稽納二 電池（1 3 )之兩端； 端’負極連接該電池（1 3)之 極體ZD2係與該電阻R1跨接於該M324920 VIII, new description: f new technology field] This creation is about a solar power control device, especially an automatic judgment when the light source is sufficient to charge the battery. 'When the light source is insufficient, it can be provided by the battery according to whether the battery power is sufficient. Electricity or solar power control devices that are powered by a power supply. [Prior Art] As petroleum energy gradually (4), it has caused the world to develop alternative energy. 'In all alternative energy sources, solar energy is regarded as economic and environmentally friendly.' Therefore, the use of solar energy has gradually attracted attention. The most basic way of using solar energy is to use solar panels to collect solar energy and then use it directly, or convert it to electricity for use at the back end. / Because the sun does not hang high in the sky all day, when the sun goes down, the device that relies on solar energy as a source of electricity can no longer operate. This situation limits the use of solar devices. = For example, since it is usually unnecessary to turn on the lighting installation during the day, and the night is not necessary to turn on the (4) device', this situation is just opposite to the operation of the sun, which makes it impossible for the lighting device to use solar energy as a source of electricity. Yang furnace = 3, there is no effective power management mechanism, which makes the transportation of the material more efficient and provides more applications in a step-by-step manner. [New content] In providing a kind of solar power control, the main purpose of this creation is M324920 device, which can automatically judge the battery when the light source is sufficient. When the light source is insufficient, the battery can be powered according to whether the battery power is sufficient or Power is supplied by the power supply. The main technical means for achieving the foregoing objective is that the solar power control device comprises: a solar module comprising a solar panel, a voltage conversion circuit and at least one battery, wherein the solar panel is configured to receive light energy and convert The DC power output is further connected to the solar panel to convert the direct current of the solar panel output, and the battery is connected to the voltage conversion circuit to save the transformed DC power; a light intensity detecting unit Connecting the solar panel to determine whether the light energy received by the solar panel is sufficient; a switch unit is connected to the light intensity detecting unit and controlled to switch, and the switch unit further includes two switchers, one of which switches The open relationship is connected between the solar panel and the voltage conversion circuit to switch whether the solar panel and the voltage conversion circuit establish a connection according to whether the light energy received by the solar panel is sufficient, and another switching relationship is connected to the battery and a load. Between, to switch whether the light is received according to whether the solar energy received by the solar panel is sufficient Providing power to the load; - a power selection circuit that connects the battery, an external power source, and a load to measure whether the battery power is sufficient and controls whether a connection between the external power source and the load is established; an over-discharge limiting circuit is connected The battery detects whether the power of the battery is sufficient, and the over-discharge limiting circuit further includes a limit switch, and the limit opening M324920 is connected between the switch of the switch unit and the load to switch whether the battery power is sufficient or not. The battery provides the above-mentioned technical means, which can automatically adjust the use of solar energy under safe and efficient conditions, charge the battery when the sunlight is charged, but does not supply power to the load, and the sky is dimmed and then the battery is powered by the load, such as battery power. If it is insufficient, the external power supply will supply power to the load; if the battery is fully charged, the external power supply will be automatically cut off, and the battery will supply power to the load. [Embodiment] With regard to a preferred embodiment of the present invention, please refer to the first figure, including - too, energy module (1 〇), a light intensity (four) unit (2 〇), - switch unit (3) Q), - power selection circuit (4 ◦) and an over-discharge limiting circuit (50). As shown in the second figure, the above solar module (1) includes: 9 plates (1 1 ) for receiving light energy and converted into direct current output; - voltage conversion circuit (2 2 ), connection The solar panel (1 1 ) is used to step down the direct current output of the solar panel, and the voltage conversion circuit (12) can be a DC/DC conversion circuit or a pulse width modulation (Μα W^idth Modulation, referred to as pffM) type voltage converter; please refer to the second figure. In the embodiment, the voltage conversion circuit (1 2 ) is a DC/DC conversion circuit, which adopts a .QFF charging method to achieve fast charging. To avoid the purpose of overcharging; if the voltage conversion circuit (12) adopts a PWM voltage converter, the maximum power tracking function can be used to convert the voltage with maximum power; and to J A battery (13) is connected to the voltage conversion circuit (丄2) to store the stepped DC power. The light intensity pre-measurement unit (20) is connected to the solar panel (11); please cooperate with the second figure. In the embodiment, the light intensity detection early (20) is determined by Whether the DC voltage output by the solar panel (completed) is greater than the - voltage value (for example, 6 2V) to determine whether the light energy pure by the solar panel (11) is charged, and the light intensity (20) includes: The first-signal diode ZD1 has a positive electrode connected to the solar panel (i 丄j, the ta-day body Q1' whose base is connected to the negative electrode of the first genus diode; and a second transistor Q2 The base is connected to the second electrode of the first transistor qi to connect the collector of the first transistor Q1; and the hope that the light is sufficient, the first-signal diode ZD1 is turned on, thereby Brother: The transistor Q1 and the second transistor Q2 are turned on. The above switching unit (3 η, in, by the top) Η Λ # ) is connected to the light intensity detecting unit (2 U) and controlled by the switching; It ( ^ π first and second diagrams, the switch single (30) is a relay, which includes: an excitation coil (3 1 ), a system 3 Chagu # 〇) flute - Shi B 糸 is connected to the collector of the first transistor Q2 of the light intensity detecting unit (2 U ); a first magnetic sensor switch ( ) is connected to the solar panel (1 Ο ) of the solar module M324920 (1) i) and the voltage conversion circuit (丄2), wherein the common node of the first magnetic induction open @ (3 2) is connected to the voltage conversion circuit (1 2 ), and the first magnetic induction switch (3 2 ) is normally open The node is connected to the solar panel (1 i and a second magnetic induction switch (33), which is connected to the battery (13), wherein a common node of the second magnetic induction switch (33) is connected to the battery (13) The normally closed node of the second magnetic induction switch (33) is connected to a load (60). In this embodiment, the load (6〇) includes a driving circuit (6 1 ) and a high-intensity gas discharge ( To extract an intensity discharge (HID) lamp (6 2 ); if the second transistor Q2 is turned on, the excitation coil (3 work) will be excited, so that the two magnetic induction switches (3 2 ) ( 3 3 ) are The closed node is switched to the normally open node, so that the solar panel (1 1 ) and the voltage conversion circuit (1 2 ) are connected, so The direct current output from the solar panel (1丄) is input to the voltage conversion circuit (12), and further the battery (13) is charged. When the second transistor Q2 is not turned on, the excitation coil (3丄) is no longer excited. Therefore, the two magnetic induction switches (3 2 ) ( 3 3 ) are white & 曰, the hoisting node is switched to the normally closed node to cut off between the solar panel (丄i) and the voltage conversion circuit (1 2 ) Connect and connect the battery (1 3 ) to the load (60). The power selection circuit (40) is connected to the battery (13), an external power supply (7 ◦), and a load (60) to measure whether the power of the battery (丄3) is sufficient, and to control whether an external power source is established. The connection between the (7 〇) and the load (60); in this embodiment, the power selection circuit M324920 (4 Ο) includes: a resistor R1 having one end connected to the solar module (1 〇) The battery (1 3 ) is a terminal; the second semiconductor diode ZD2 has a positive electrode connected to the other end of the resistor R1, so the two ends of the second battery (1 3 ); The pole body ZD2 of the battery (13) is connected to the resistor R1
力率電晶體（4 1 )，其閘極係連接該電阻R1和 第二稽納二極體ZD2的連接節點； 隻壓器（4 2 )，其一次側係連接該功率電晶體（4 1 )的汲極；及 一電子開關，於本實施例中係為一矽控整流器 (Silic〇n-Contr〇lled Rectifier，簡稱 scr) si，其陽 極係連接該外部電源（7 〇 )，陰極係連接該負載（6 〇 )， 閑極則連接該變壓器（4 2 )之二次側；若電池（工3 ) 之電壓夠高（例如高於12V)，則該第二稽納二極體ZD2 ♦即導通，故該功率電晶體（4工）即截止，令該石夕控整流 -器' S1亦截止；反之若電池（1 3 )之電壓並未高於一電 壓值（例如12v)時，該第二稽納二極體ZD2即不導通， 故》亥功率電晶體（41)導通，因而透過該變壓器（42) 予忒矽控整流器S1之閘極一觸發電壓而令其導通，此時 該外部電源（7 0 )開始提供電力予負載（6 〇 ); 因此當該開關單元（3 ◦)的第二磁感應開關（3 3 ) ::換至常閉節點令電池（i 3 )與負載（6 〇 )連線時， 右電池（1 3 )電力不足，則該電源選擇電路（4 〇 )將 M324920 可偵知並切換由外部電源（7 〇 )提供電力予負載（6 〇 )。 上述過放限制電路（5 0 )係連接該電池（i 3 )以 偵測電池（1 3 ) <電力是否充足；請配合第二圖所示以 於本實施例令，該過放限制電路（5 〇 )係包括·· 第一稽納一極體ZD3，其正極係連接該開關單元（3 〇 )之第二磁感應開關（3 3 )的常閉節點； 一第三電晶體Q3,其基極係連接該第三稽納二極體zd3 之負極； 第四電晶體Q4，其基極係連接該第三電晶體⑽之 射極，集極則連接該第三電晶體Q3之集極；及 一限制開關，於本實施例中係為一繼電器，其包括一 激磁線圈（5 1 )、一第一接點開關（5 2 ) g及一第二 接點開關（5 3 )，其中該激磁線圈（5 2 )係連接該第 二與第四電晶冑Q3、q4之集極，另該第一接點開關（5 =係連接於該開關單元（3〇)之第二磁感應開關（3 的吊閉即點和負載（6 〇 )之間，而該第二接點開關 (5 3)係連接於該電池（工3)與—外部供電輸出端w =間，又該外部供電輸出端VQUt可直接提供——的直 机電源（6 4 )或透過—直流/交流轉換器（dc_ac ) ( 6 3 )提供一交流電源； A當電池（1 3 )放電時，如電池（1 3 )之放電電壓 則虡第一稽納—極體ZD3會導通，且該限制開關的 、文磁線圈（5 1 )激磁，令該兩接點開關（5 2 ) ( 5 3 ) 呈閉路，使電池（13)可正常供電予負載（6〇)與直 M324920 流/交流轉換器（DC-AC) ( 6 3 )，以及提供直流電源（6 4 )，反之則第二稽納二極體ZD3不導通，令該限制開關 的激磁線圈（5 1 )不再激磁，使該兩接點開關（$ 2 ) (5 3 )呈開路，故電池（1 3 )將停止放電。 又為配合驅動該HID燈（62)，該驅動電路（61) 係為一高壓點火器，其係用以將該電池（i 3 )輸出的電 -壓轉換成特定的高電壓（例如23,000伏特）以驅動該HID φ 燈管（6 2 );請配合參閱第四圖所示，於本實施例中， 該高壓點火器主要係利用兩組驅動器（6 i6丄2 ) 驅動四組場效電晶體q9〜Q12，以轉換產生高電壓。由於該 高壓點火器為已知裝置，容不進一步詳述其工作原理。 由上述可知，當光線充足時即由太陽能板對電池充 電，待光線不足時，再令電池提供電力予負載，如電池電 力不足，再由外部電源取代提供電力予負載，以有效率地 利用由太陽能轉換之電能。 鲁、’、不上所述，本創作實為一極具進步性與實用性之佳 、 作，且未見於刊物或公開使用，符合新型專利之申請要件， 爰依法提出申請。 【圖式簡單說明】 第一圖·係本創作一較佳實施例之功能方塊圖。 第二圖：係本創作一較佳實施例之電路圖。 第二圖·係本創作一較佳實施例中_電壓轉換電路為 一直流/直流轉換電路之電路圖。 11a force rate transistor (4 1 ) having a gate connected to a connection node of the resistor R1 and a second arrester diode ZD2; a voltage regulator (4 2 ) having a primary side connected to the power transistor (4 1 And an electronic switch, in this embodiment, is a controlled rectifier (Silic〇n-Contr〇lled Rectifier, referred to as scr) si, the anode is connected to the external power source (7 〇), the cathode system Connect the load (6 〇), the idle pole is connected to the secondary side of the transformer (4 2 ); if the voltage of the battery (Work 3) is high enough (for example, higher than 12V), the second sigma diode ZD2 ♦ that is, the conduction, so the power transistor (4 work) is cut off, so that the stone control rectifier - S1 is also cut off; if the voltage of the battery (13) is not higher than a voltage value (such as 12v) The second register diode ZD2 is non-conducting, so that the "power transistor (41) is turned on, so that the voltage of the gate of the rectifier S1 is controlled by the transformer (42) to turn it on. When the external power source (70) starts to supply power to the load (6 〇); therefore, when the second magnetic induction of the switching unit (3 ◦) is turned on (3 3 ) :: When switching to the normally closed node, when the battery (i 3 ) is connected to the load (6 〇), if the right battery (1 3 ) is insufficient, the power selection circuit (4 〇) will detect the M324920. And switch the power supplied by the external power supply (7 〇) to the load (6 〇). The overdischarge limiting circuit (50) is connected to the battery (i3) to detect the battery (13) < whether the power is sufficient; please cooperate with the second embodiment to enable the overdischarge limiting circuit (5 〇) is a first-in-one body ZD3 whose positive pole is connected to a normally closed node of a second magnetic induction switch (3 3 ) of the switch unit (3 ;); a third transistor Q3, The base is connected to the negative electrode of the third semiconductor diode zd3; the fourth transistor Q4 has a base connected to the emitter of the third transistor (10), and a collector connected to the collector of the third transistor Q3 And a limit switch, which is a relay in the embodiment, comprising an excitation coil (5 1 ), a first contact switch (5 2 ) g and a second contact switch (5 3 ), wherein The excitation coil (52) is connected to the collectors of the second and fourth electro-thermal crystals Q3, q4, and the first contact switch (5= is connected to the second magnetic induction switch of the switching unit (3〇) (3 hang between point and load (6 〇), and the second contact switch (5 3) is connected to the battery (work 3) and - external power supply output w = The external power supply output terminal VQUt can directly provide a direct power supply (6 4 ) or a DC-to-AC converter (dc_ac) (63) to provide an AC power supply; A when the battery (1 3) is discharged If the discharge voltage of the battery (1 3 ) is 虡 first, the body ZD3 will be turned on, and the magnetic coil (5 1 ) of the limit switch is excited to make the two-contact switch (5 2 ) (5) 3) Closed circuit, so that the battery (13) can supply power to the load (6〇) and the straight M324920 current/AC converter (DC-AC) (6 3 ), and provide DC power (6 4 ), otherwise the second The Zener diode ZD3 is not conducting, so that the excitation coil (5 1 ) of the limit switch is no longer excited, so that the two contact switches ($ 2 ) (5 3 ) are open, so the battery (13) will stop discharging. In order to cooperate with driving the HID lamp (62), the driving circuit (61) is a high voltage igniter for converting the electric-voltage output of the battery (i 3 ) into a specific high voltage (for example, 23,000). Volt) to drive the HID φ lamp (6 2 ); please refer to the fourth figure, in this embodiment, the high voltage igniter mainly uses two groups The driver (6 i6 丄 2 ) drives four sets of field effect transistors q9 to Q12 to convert to generate a high voltage. Since the high voltage igniter is a known device, the operation principle thereof will not be further described. When the solar panel is used to charge the battery, when the light is insufficient, the battery is supplied with power to the load. If the battery power is insufficient, the external power source replaces the power supply to the load to efficiently utilize the energy converted by the solar energy. 'Under the above, this creation is a very progressive and practical work, and it is not found in the publication or public use, and it meets the application requirements of the new patent. BRIEF DESCRIPTION OF THE DRAWINGS The first figure is a functional block diagram of a preferred embodiment of the present invention. Second Figure: A circuit diagram of a preferred embodiment of the present invention. The second figure is a circuit diagram of a DC/DC conversion circuit in a preferred embodiment. 11
M324920 第四圖··係本創作一較佳實施例中一高壓點火器之電 路圖。 【主要元件符號說明】 (1〇)太陽能模組 (1 1 )太陽能板 (12)電壓轉換電路 (1 3 )電池 (2 0 )光強度偵測單元 (3 0 )開關單元 (3 2 )第一磁感應開關 (4 0 )電源選擇電路 (4 1 )功率電晶體 (5 0 )過放限制電路 (5 2 )第一接點開關 (6 0 )負載 (6 1 )驅動電路 (611) ( 6 1 2 )驅1 (6 2)高強度氣體放電 (6 3 )直流/交流轉換器 (7 0 )外部電源 (3 1 )激磁線圈 (3 3 )第二磁感應開關 (4 2 )變壓器 (5 1 )激磁線圈 (5 3 )第二接點開關 器 (6 4 )直流電源 < S ) 12M324920 Fig. 4 is a circuit diagram of a high voltage igniter in a preferred embodiment of the present invention. [Main component symbol description] (1〇) Solar module (1 1) Solar panel (12) Voltage conversion circuit (1 3 ) Battery (2 0 ) Light intensity detection unit (3 0 ) Switch unit (3 2 ) A magnetic induction switch (40) power selection circuit (4 1) power transistor (50) over-discharge limiting circuit (5 2) first contact switch (60) load (6 1) drive circuit (611) (6 1 2 ) Drive 1 (6 2) High-intensity gas discharge (6 3 ) DC/AC converter (7 0 ) External power supply (3 1 ) Excitation coil (3 3 ) Second magnetic induction switch (4 2 ) Transformer (5 1 ) excitation coil (5 3 ) second contact switch (6 4 ) DC power supply < S ) 12