怎样测试汽车用继电器（中英文）

How to Test Relays for Automotive Applications

继电器可用在什么地方？

Where are Relays used?

想象一下汽车中的一个简单应用程序； 它的车头灯。 在傍晚和夜间，轻按或转动汽车方向盘附近的开关，大灯就会打开。

Imagine a simple application in car; its headlights. During evening and nighttime, flick or twist a switch near car’s steering wheel and the headlights turn on.

在外面，它看起来像一个简单的应用程序和电路。 但如果再深入一点，就能理解中继在这些场景中的用处。 汽车的前灯是大功率设备，可消耗 55W 至 100W 或更多的功率。 汽车电脑负责读取大灯开启开关，并为大灯供电，但由于是低功耗低电压设备，不能直接供电，直接将大灯接到车上会烧毁电脑。 必须使用中间设备，它可以接受来自计算机的命令并为前照灯供电。 这个装置是继电器。

On the outside, it looks like a simple application and circuit. But if dig a little bit deeper, can understand how relays are useful in these scenarios. The headlights in car are high-power devices that draw anywhere between 55W to 100W or more power. The car’s computer, which is responsible for reading the headlight turn on the switch, and providing power to the headlights, cannot directly supply the power as it is a low power and low voltage device and it will burn if we connect headlights directly to the car’s computer. Have to use an intermediary device, which can accept commands from the computer and provide power to the headlights. This device is Relay.

如果汽车的计算机能够以某种方式为继电器线圈通电并将大灯连接到 NO 端子，则可以轻松控制大灯而不会烧毁或损坏任何组件。 这正是带有前灯的实际汽车中发生的情况。

If the car’s computer can somehow energize the coils of the relay and connect the headlights to NO terminal, then can easily control the headlights without burning or damaging any components. This is exactly what happens in an actual car with its headlights.

当打开车内的大灯开关时，其计算机会读取此开关并激活继电器的线圈。 继电器的衔铁切换其位置，大灯亮起。 当关闭大灯开关时，汽车的电脑会去激活继电器的线圈，继电器的衔铁切换回默认触点。

When turn on the headlights switch in the car, its computer reads this switch and activates the coil of the relay. The relay’s armature switches its position and the headlight turns on. When turn off the headlight switch, the car’s computer will deactivate the coil of the relay, and the armature of the relay switches back to the default contact.

如何测试继电器？

How To Test a Relay?

从上面的解释可以看出，继电器是极其重要的电子设备，它可以使微控制器等小功率设备控制大功率设备。 由于继电器是机械设备，随着时间的推移它们可能会出现故障，因此必须检查继电器是否正常工作。 如果它不起作用，则必须立即更换新的。

It is clear from the above explanation that relays are extremely important electronic devices, which enable low-powered devices such as microcontrollers to control high-powered devices. As relays are mechanical devices, they can become faulty over time and it is essential to check whether a relay is working properly or not. If it is not working, then have to immediately replace it with a new one.

但是如何测试继电器呢？ 有多种方法可以检查继电器是否按预期工作。 将看到几种测试继电器的方法，重要的是，将学习如何使用万用表测试继电器。

But how to test a relay? There are different ways to check if a relay is working as expected or not. Will see a couple of methods to test a relay and importantly, will learn how to test a relay with a multimeter.

如何用直流电源测试继电器？

How to Test a Relay with DC Power Supply?

在第一种方法中，将简单地为继电器线圈通电和断电，并查看电枢是否在两个端子之间切换。 假设是 12V 继电器，将线圈端子连接到 12V 直流电源或带开关的电池。

In the first method, will simply energize and de-energize the coil of the relay and see if the armature is switching between the two terminals. Assuming a 12V relay, connect the coil terminals to a 12V DC Power Supply or a battery with a switch.

如果关闭开关，它会完成电路并激活线圈。 这应该使电枢切换到常开触点。 如果打开开关，则电枢应回到常闭触点。

If close the switch, it completes the circuit and activates the coil. This should make the armature switch to Normally Open contact. If open the switch, then the armature should go back to the Normally Closed contact.

这是一种测试继电器的简单方法，尤其是汽车继电器，因为可以随时使用 12V 电池。

This is a simple method for testing relays, especially automotive relays as you readily have access to a 12V battery.

如何用电路测试继电器？

How to Test a Relay with a Circuit?

对于下一个方法，将使用简单的组件构建一个小电路并测试继电器是否工作。 这种方法对电路和 PCB 中使用的继电器很有用，但也可以测试汽车继电器。

For the next method, will build a small circuit using simple components and test if the relay is working or not. This method is useful for relays used in circuits and PCBs but can also test automotive relays as well.

再次假设一个 12V 继电器，如果为晶体管的基极提供 5V，它会打开并激活线圈。 如果继电器工作正常，电枢触点切换位置并点亮 LED。

Once again assuming a 12V relay, if supply 5V to the base of the transistor, it turns on and activates the coil. If the relay is working properly, the armature contacts switches position and light up the LED.

如何用万用表测试继电器？

How to Test a Relay with a Multimeter?

最后，将了解如何使用万用表测试继电器。 这是测试继电器的最简单方法之一。 从电路或汽车上取出继电器。 将万用表置于电阻测量模式（欧姆表）。 如果有手动量程万用表，将量程表置于最小量程（200Ω 或类似值）。

Finally, will see how to test a relay with a multimeter. This is one of the easiest ways to test a relay. Take out the relay from the circuit or from the car. Put the multimeter in Resistance Measurement mode (Ohmmeter). If have a manual ranging multimeter, put the range meter in minimum range (200Ω or similar value).

取出万用表的导线并将它们连接到继电器的线圈端子上。 对于普通线圈，万用表的读数应介于 40Ω 至 120Ω 之间。 如果线圈损坏，即开路，则仪表显示超出范围，您必须更换继电器。

Take the leads of the multimeter and connect them across the coil terminals of the relay. For a normal coil, the multimeter should read anywhere between 40Ω to 120Ω. If the coil is damaged i.e., it is open, the meter shows out of range and you have to replace the relay.

万用表可以做的另一项测试是继电器的三个大功率触点之间的导通性。 当继电器处于断电状态时，COM 端子必须连接到常闭 (NC) 端子。 但是一旦继电器通电，COM 端子就会切换并与常开端子接触。

Another test we can do with the multimeter is the continuity between the three high-power contacts of the relay. When the relay is in a de-energized state, the COM terminal must be connected to Normally Closed (NC) terminal. But as soon as we energize the relay, the COM terminal switches and makes contact with the Normally Open terminal.

因此，要对此进行测试，请将万用表置于连续性模式，并在继电器未激活的情况下，将万用表的导线连接在 COM 和 NC 端子之间。 如果继电器触点正常，万用表应启动蜂鸣器。

So, to test this, put the multimeter in continuity mode and while the relay is not activated, connect the leads of the multimeter between the COM and NC terminals. The multimeter should start the buzzer if the relay contacts are okay.

现在，为继电器通电并测试 COM 和 NO 端子之间的连续性。 如果蜂鸣器在两种情况下都被激活，则继电器正常。 但如果任何测试失败，则可能是继电器故障。

Now, energize the relay and test for continuity between COM and NO terminals. If the buzzer is activated in both cases, then the relay is well and good. But if any test fails, then it might be a faulty relay.

声明：

- 文章转载自网络，由爱泽工业翻译，如有侵权，请联系删除！

- 如有偏颇，欢迎指正！