Using a Relay to Control a Linear Actuator
In this post I'm going to go over how to use a relay to control the motion of a linear actuator. I'll cover not only how to use a relay to control your actuator, but also some situations where you might want to. We offer a simple relay kit in our store that is designed to work with electric micro linear actuators.
For larger projects, there are relay boards available with 2, 4 and even 8 channels. You can find larger relays at RobotShop.
What Is A Relay
A relay is simply a switching mechanism. It allows you to control a big switch with a smaller switch without the current of the primary load running through the smaller switch.
How A Relay Works
As I mentioned above, a relay adds a second switch into your system. Basically, a relay is just a switch that is controlled by a smaller switch.
They work by using a small current from the input source to activate an electromagnet. The electromagnet pulls a switch and allows a higher current to flow through the opposite side of the relay. It's a cheap and effective way to switch a larger load.
Why Use A Relay
Sometimes you want or need to use a switch that is not rated for the load of the device you're working with. This requires a relay to switch the higher load.
Another example is if you're using a microcomputer or microcontroller such as a Raspberry Pi or an Arduino. They are only capable of a very small electrical output. A relay would be required to handle any significant electrical load.
Some Examples of When You Might Want To Use A Relay
Vehicle Applications: Relays are popular for vehicle automation applications. They are ideal because it's possible to tap into an existing circuit within the vehicle to use as a switch for the relay. An example would be if you're using actuators to drive pop-up headlights, a relay could activate them when you turn on your headlights or even your ignition.
The low-power side of a relay draws very little current so it's often possible to tap into an existing circuit without drawing too much current for the circuit to handle.
Low-Current Applications: This could be any microcontroller application. We have thousands of customers using our actuators with Arduino. Adding in a relay kit makes switching power on and off safe and fairly simple.
Momentary Applications: By using our DPDT relay, you can make your actuator extend with the push of a button, and retract automatically when you release the button. By reversing the actuator's two leads, it's possible to reverse this effect. This would cause the actuator to remain extended full-time, and retract at the push of a button.
How To Connect The Actuonix Relay Kit
I've included a wiring diagram below that shows you exactly how to connect your actuator to the Actuonix relay kit. These wiring instructions remain the same whether you're using a latching or momentary switch.
Frequently Asked Questions
What is a relay and why would I use one with my linear actuator?
A relay is a switching device that allows you to control a larger electrical load with a smaller control signal. It's useful with linear actuators when your control device, like a microcontroller, can't handle the actuator's power requirements directly.
Can I use a relay with Arduino or Raspberry Pi?
Yes, relays are commonly used with Arduino and Raspberry Pi for controlling devices that require more power than the microcontroller can provide. This includes linear actuators, lights, motors, and more.
How do I choose the right relay for my linear actuator?
Choosing the right relay depends on your actuator's voltage and current requirements. That said, the relays available on this site are compatible with all Actuonix S-Series and P-Series actuators. That said, please be aware that if you are using a P-Series actuator without an LAC board, it is possible to damage the actuator by running it to its end limit. Consider using the P-Series with an LAC or using an external limit switch kit.
