交流电源固态继电器或SSR是一种设备，用于通过隔离的最小直流电压触发器在主电位上切换重型交流负载，而无需结合机械的移动接触。
在这篇文章中，我们学习了如何使用TRIAC，BJTS，零交叉光耦合器构造简单的主电源固态继电器或SSR电路。
固态SSR优于机械继电器
Mechanical type of relays can be pretty inefficient in applications which require highly smooth, very swift and clean switching.
建议的SSR电路可以在家中构建，并用于需要真正复杂的负载处理的地方。
本文描述了带有内置零交叉检测器内置零交叉检测器的固态接力电路。
该电路非常易于理解和构建，但提供了有用的功能，例如清洁开关，没有RF干扰，并且能够处理最多500瓦的负载。我们已经学到了很多有关继电器及其功能的知识。
我们知道，这些设备用于通过外部隔离的触点切换重型电荷，这是响应从电子电路输出中收到的小电脉冲。
通常，触发输入位于继电器线圈电压的附近，可能为6、12或24 V dc，而继电器接触的负载和电流大多在AC电势的水平上。
基本上，继电器之所以有用，是因为它们能够切换与触点的重型连接，而无需使危险的潜力与易受攻击的电子电路接触。
但是，优点伴随着一些不容忽视的关键缺点。由于触点涉及机械操作，因此有时会非常无能为力，需要高度准确，快速，高效的开关。
Mechanical relays also have the bad reputation of generating RF interference and noise during switching which also results in its contacts degradation with time.
请为基于MOSFET的SSRrefer to this post
Using SCR or Triac for Making SSR
Triacs and SCRs are thought to be good replacements in places where the above relays prove inefficient, however these too may involve RF interference generation problems while operating.
Also SCRs and Triacs when integrated directly to electronic circuits require the circuit’s ground line to be connected with its cathode, which means the circuit section is now no longer isolated from the lethal AC voltages from the device – a serious drawback as far as safety to the user is concerned.
但是，如果完全解决上述缺点，则可以非常有效地实施TRIAC。因此，必须用TRIACS去除的两件事，如果要有效替换为继电器，则在转换时进行了RF干扰，并且将危险的电源进入电路。
固态继电器的设计完全使用上述规格，从而消除了RF推理，并且还使两个阶段完全与其他阶段保持了。
商业SSR可能非常昂贵，如果出现任何问题，则无法维修。但是，您将全部制作固态中继并将其用于所需的应用程序可能就是“医生订购的”。由于可以使用离散的电子组件构建它，因此可以完全可以修复，可修改并为您提供有关系统内部操作的清晰想法。
在这里，我们将研究简单的220V固态继电器的制造。
How it Works
如上一节所述，在拟议的SSR或固态继电器电路设计中，通过强迫TRIAC仅在AC正弦相的零标记上切换来检查RF干扰，并使用光耦合器确保输入是远离带有TRIAC电路的AC主电势。
Let’s try to understand how the circuit functions:
As shown in the diagram the opto coupler becomes the portal between the trigger and the switching circuit. The input trigger is applied to the LED of the opto which illuminates and makes the photo-transistor conduct.
The voltage from the photo-transistor passes across the collector to the emitter and finally reaches the triac’s gate to operate it.
上述操作非常普通，通常与所有三元人的触发器相关。但是，这可能不足以消除RF噪声。
部分由三个晶体管和年代ome resistors are especially introduced with the view of checking the RF generation, by ensuring that the triac conducts only in the vicinity of the zero thresholds of the AC sine waveform.
When AC mains is applied to the circuit, a rectified DC becomes available at the collector of the opto transistor and it conducts as explained above, however the voltage at the junction of the resistors connected to the base of T1 is so adjusted that it conducts immediately after the AC waveform rises above the 7 volt mark. For so long the waveform stays above this level keeps T1 switched ON.
这是基于光晶晶体管的收集器电压，抑制了TRIAC的导电，但是当电压达到7伏且接近零时，晶体管停止导电以允许TRIAC切换。
The process is repeated during the negative half cycle when T2, T3 conducts in response to voltages above minus 7 volts again making sute that the triac fires only when the phase potential nears zero, effectively eliminating the induction of zero crossing RF interferences.
Circuit Diagram of Triac based Solid State Relay Circuit
零件清单
- R1 = 120 K，
- r2 = 680k，
- R3 = 1 K,
- R4 = 330 K,
- R5 = 1 m，
- R6 = 100 Ohms 1 W,
- C1 = 220 UF / 25 V，
- C2 = 474 /400 V金属化聚酯
- C3 = 0.22UF/400V PPC
- Z1 = 30 volts, 1 W,
- T1，T2 = BC547B，
- T3 = BC557B,
- tr1 = bt 36，
- OP1 = MCT2E或类似。
PCB Layout
使用SCR光电耦合器4N40
Today with the advent of modern opto-couplers, making a high grade solid state relay (SSR) has really become easy. The 4N40 is one of these devices which uses a photo SCR for the required isolated triggering of an AC load.
This opto-coupler can be simply configured for creating a highly reliable and effective SSR circuit. This circuit can be used for triggering a 220V load through a thoroughly isolated 5V logic control, as shown below:
SSR使用MOC3020光耦合器IC和TRIAC
The ICs MOC3040 or MOC3041 are similar to a normalopto-coupler其中典型的光晶体管由光横幅（100 mA/400增值税25°C）取代。该IC的主要特征是，它实际上允许在电路中使用所有形式的硅控制整流器（SCR）和TRIACS，通常不可能使用光晶体管based opto-couplers. Determining the type of triac for making a 220V operated solid state relay is possible, based on the kind of load to be operated by the relay.
考虑到SSR负载是电阻的，可以令人满意地使用TRIAC TIC 226D/400 V。如果为负载指定电感载荷，则可能需要630 V TRIAC，例如，TIC 226m型。请记住，电容器C1的工作电压应匹配使用的TRIAC的规格。
输入侧电阻R1可以根据输入电压的水平V确定in。可以使用以下公式评估其价值：
R1 = 1000 (Vin-1.3）/ioc。
In this equation Vin将在伏特中，R1在欧姆中，我oc将在MA中，这表明通过MOC光耦合器中的LED电流。
If we consider the LED side input of the opto coupler to be Vin= 12 V，当前ioc= 30 mA (which are the standard specifications of the MOC 3040 opto coupler), the worked out value of R1 will be equal to 356 Ohms, and we can round it of to a practically feasible value of 330 Ohms.
在MOC 3041中，当前LED的IOC仅为15 mA，这意味着，实际上，可以允许R1限制电阻值约为680欧姆。该220V固态继电器可以处理的最大电流约为8安培，对于更高的功率，您可以相应地更改TRIAC
图片提供：远方
Hi Swagatam
I am looking for an SSR which can handle 100A 12V load, input voltage 6 – 12V.
I assume the above circuit is suitable for AC main loads.
Hi Abu-Hafss, if the shown triac is rated adequately as per the specified load current then surely it can be applied for the same.
Hi Swagatam
我在某个地方读到，DC SSR不应具有零越过检测器，并且应该具有SCR而不是创伤。
HI ABU-HAFSS，上面的电路设计用于控制主电位的交流负载，因此零交叉对抑制噪声和干扰是有利的。
这就是我要问的，您能为我提供一些DC SSR的设计，而无需零越过探测器，能够在12V时处理100A。
…if possible i'll try to design and publish soon.
你好，先生
感谢您的帖子
May I know the value of C3?
Thanks
Hi Ngo, You can use 0.22uF 400V for C3
Hi,
How to modify this circuit to use it with 120v 60Hz?
Does it need to be modified?
Thanks.
No, it does not require any specific modifications for 120V. This is unrelated, I think there should have been a diode 1N4007 in between R3, and C2 line, cathode towards R3…And aslo a 33 ohm 1 watt in series with the input AC line to safeguard the zener!
是否可以使用SCR或其他固态设备控制220VAC 5000至10000瓦加热器？
是的，绝对有可能！
斯瓦格坦, can you help me get started, components, circuits etc.
Thanks
Jim, you can try the following concept:
//www.addme-blog.com/how-to-make-25-amp-1500-watts-heater/
All capacitors are 400V rated and the resistors are 1/4 watt 5%
先生，该电路适合在用于传递主电源和发电机之间的负载的ATS系统上更换接触器？约50安培。
不，该电路不能用作转换继电器。
你好斯瓦加塔姆先生，
希望你好好安全。正在与MOC3021和BT136进行固态继电器。并计划与PIR传感器集成。我的查询是如何在传感器模式之间切换它，并始终“轻上”模式。
以前，我用电磁继电器制作了电路，并将光线直接连接到相线，并通过两道归型开关连接到相线。因此，我可以在传感器之间切换并始终开启。
现在将TRIAC与光线连接起来，我想我无法将光直接连接到开关，并且可能会损坏TRIAC。请帮助。
Thanks Mr.Sriram, You can simply connect a switch between the (+) and OUT pins of the PIR to bypass the positive directly to the MOC input, and this will enable always Light ON or PIR mode operation.
IS THERE ANY SIMPLE SOLID STATE DC RELAY CIRCUIT WHICH OPERATES FROM 6VOLT TO 14VOLTS.
NOTE- PURPOSE IS FOR FLASHING THE LED AND LOAD WILL BE APPROX 60 WATTS @ 12.8 VOLTS
Use a BJT or MOSFET with the output of any opto coupler, that will fulfill your requirement.
你好。
我可以使用什么而不是SC 1460？
You can use any standard triac.
Can I use “Circuit Diagram of Triac based Solid State Relay Circuit” with a 2HP water pump?
Yes you can use it!
感谢所有这些信息，我想知道是否可以使用一个MOC3040驱动两个TRIAC控制两条交流单独的线路？
可以使用双向可控硅+ MOC3040为直流/AC load control?
您是否建议使用保险丝进行TRIAC保护？
不客气！是的，使用TRIAC和MOC OptoCOPLER可以使用所有这些功能。保险丝始终是所有交流电路的推荐设备，因此必须包括在内。
嗨，先生。感谢您的好意回答我。实际上，我对电子产品感兴趣。我从事它多年。我在朋友工作室中发现了许多旧的SCR。他们很大，我认为150安培。我想他们用它们来控制儿童电动汽车。现在，我喜欢将它们用作SSR控制器。我需要一些帮助 。首先，我知道我应该将它们并行用作抽动，但是我不知道它是否有效，如果它有效，您认为我可以在上图中使用它。 ???? . can you help me. thanks.
嗨，是的，您可以在上面显示的电路中使用SCR，但是作为SCR而不是TRIAC，它只能与50％的AC周期一起使用……。
你好 。如果我以相反的方式平行两个SCR，我有很多，我可以将其用作TRIAC吗？。如何计算电压和Miliampers同时发射两个？？？。可能吗 ？我的SCR是
BSTL3590。大，250安培和1.2 kV。你可以帮我吗？
thanks for your help.
Hi, I am not entirely sure, but you can give it a try. You can connect the two gates with each other, having a 1K resistor in series with each of the SCR gates. After this you can try switching the common end of the resistors with a DC signal and check the response.