Relay Outputs / 繼電器輸出
By now we should have a good understanding of how the inputs are used. Next up is the output circuits.
現在我們應該很好地理解了輸入是如何使用的，接下來是輸出電路。
One of the most common types of outputs available is the relay output. A relay can be used with both AC and DC loads. A load is simply a fancy word for whatever is connected to our outputs. We call it a load because we are "loading the output" with something. If we connected no load to the output (i.e. just connect it directly to a power supply) we would certainly damage the outputs. This would be similar to replacing the light bulb in the lamp you're using to read this with a piece of wire. If you did this, the lamp would draw a tremendous amount of current from the outlet and certainly pop your circuit breaker or blow your fuse or your brains. (Take our word. Please don't try it! Extremely dangerous!)
繼電器輸出是最常見的輸出類型之一。繼電器可用於交流和直流負載。負載只是與我們的輸出相連接的任何東西的一個花哨的叫法。我們稱它為負載，因為我們正在用一些東西“加載輸出”。如果我們把空載連接到輸出（即直接連接到電源），我們肯定會損壞輸出，這就像用一根電線代替你用來閱讀這篇文章的燈泡（即直接用電線連接輸出點和電源），如果你這樣做，電路中將產生大量的電流，肯定會擊穿你的斷路器、保險絲或使你的大腦短路（相信我們的話！請不要嘗試！極其危險！）。
Some common forms of a load are a solenoid, lamp, motor, etc. These "loads" come in all sizes. Electrical sizes, that is. Always check the specifications of your load before connecting it to the plc output. You always want to make sure that the maximum current it will consume is within the specifications of the plc output. If it is not within the specifications (i.e. draws too much current) it will probably damage the output. When in doubt, double check with the manufacturer to see if it can be connected without potential damage.
負載的一些常見形式是線圈、燈、電機等，這些“負載”大小不一，有各種不同的電性能。在將負載連接到PLC輸出之前，一定要檢查負載的規格。您總是希望確保它所消耗的最大電流在PLC輸出的規格範圍內。如果它不在規格範圍內(即產生太大的電流)，它可能會損壞輸出。當有疑問時，一定要與製造商再次檢查，看看它是否可以連接且沒有潛在的損害風險。
Some types of loads are very deceiving. These deceiving loads are called "inductive loads". These have a tendency to deliver a "back current" when they turn on. This back current is like a voltage spike coming through the system.
有些類型的負載具有很強的欺騙性，這些欺騙性的負載被稱為“感應負載”，當它們通電時，會產生一種“反向電流”，這個反向電流就像通過系統的電壓峰值（有可能對系統參數危害）。
A good example of an inductive load that most of us see about 6 months per year is an air conditioning unit. Perhaps in your home you have an air conditioner. (unless you live in the arctic you probably do!) Have you ever noticed that when the air conditioner "kicks on" the lights dim for a second or two. Then they return to their normal brightness. This is because when the air conditioner turns on it tries to draw a lot of current through your wiring system. After this initial "kick" it requires less current and the lights go back to normal. This could be dangerous to your PLCs output relays. It can be estimated that this kick is about 30 times the rated current of the load. Typically a diode, varistor, or other "snubber" circuit should be used to help combat any damage to the relay. Enough said. Let's see how we can use these outputs in the "real plc world".
一個很好的感應負載的例子是我們大多數人每年大約要用6個月的空調機組，也許你家裡有空調（除非你住在北極，否則你很可能有空調！）。你有沒有注意到，當空調“啟動”時，燈光會變暗一兩秒，然後它們又恢復到正常的亮度，這是因為當空調開啟的瞬間，電路里會產生大量的電流，但在空調正常啟動之後，它僅需要更少的電流來保證運轉，所以燈又回到了正常的亮度。這可能會對你的PLC輸出繼電器造成危險。據估計，這個衝擊大約是負載額定電流的30倍。通常，二極管、壓敏電阻或其他“緩衝”電路應有助於防止繼電器的任何損壞。無需多言，讓我們看看如何在“真實的plc世界”中使用這些來改善輸出質量。
Shown above is a typical method of connecting our outputs to the plc relays. Although our diagram shows the output connected to an AC supply, DC can be used as well. A relay is non-polarized and typically it can switch either AC or DC. Here the common is connected to one end of our power supply and the other end of the supply is connected to the load. The other half of our load gets connected to the actual plc output you have designated within your ladder program.
上圖顯示的是我們將負載連接到繼電器輸出型的PLC輸出端的典型方法。雖然我們的圖中顯示的輸出連接的是交流電源，直流也可以使用。繼電器是沒有極性的，通常它可以接交流也可以接直流。這裡的公共端連接到電源的一端，而電源的另一端連接到負載的一端，負載的另一端連接到您在梯形程序中指定的實際PLC的輸出點。
The relay is internal to the plc. Its circuit diagram typically looks like that shown above. When our ladder diagram tells the output to turn on, the plc will internally apply a voltage to the relay coil. This voltage will allow the proper contact to close. When the contact closes, an external current is allowed to flow through our external circuit. When the ladder diagram tells the plc to turn off the output, it will simply remove the voltage from the internal circuit thereby enabling the output contact to release. Our load will than have an open circuit and will therefore be off. Simple, isn't it?
所謂的繼電器輸出，其繼電器位於PLC內部。它的電路圖通常與上圖所示類似。當我們的梯形圖告訴輸出打開，PLC將在內部施加電壓到繼電器線圈，這個電壓將使對應的觸點閉合，當觸點閉合時，外部電流就可以流入我們的外部電路；當梯形圖告訴PLC斷開輸出時，它只需要從內部電路中移除電壓，從而使對應的輸出觸點釋放，我們的負載迴路就會斷開。是不是很簡單？
