There are two main types of electric vibrating motors: eccentric rotating mass (ERM) motors and linear resonant actuator (LRA) motors. Both work in a range of different applications, and if you are developing a product and trying to figure out which one to use, it can be hard to decide. Here are 5 signs you should choose an ERM vibrating motor.
1. You Don't Want to Deal With Springs
ERM vibrating motors work by using an unbalanced mass. As it gets currents from the DC motor, the mass starts to spin and the unbalanced part of it keeps the spinning going. With a LRA motor, in contrast, the vibrating action is dependent on a spring. If you don't want to deal with springs, you may need to choose an LRA motor.
2. You Need a Small Motor
Both LRA and ERM motors can come in a range of sizes, but it's usually easier to get ERM motors in the smallest sizes possible. In fact, you can find coreless ERM vibrating motors that have a very small eccentric mass. These motors can be about the size of a coin.
3. You Want an Encapsulated Motors
The coin-shaped motors mentioned above are one example of an encapsulated motor. However, you can also get other sizes and shapes of ERM motors that are encapsulated. This works for many different types of product designs.
In particular, if you are making a child's toy and you want to ensure that they can't access any of the motor's internal components, you may want to opt for an encapsulated design.
4. You Want the Most Popular Option
Generally, ERM vibrating motors are more popular than their linear counterparts. That is something to keep in mind. When you choose the more popular option, it's easier to find replacement parts or to find people who can work on the motors as needed. That isn't necessarily the case when you choose the option that is not as common.
5. You're Willing to Sacrifice Longevity for Simplicity
Compared to ERM motors, LRA motors tend to last longer. If longevity is your number one goal, you may want to opt for an LRA motor. However, LRA motors are almost always more complex than ERM vibrating motors. As a result, if you don't want to deal with all that complexity and you're willing to sacrifice a bit of that longevity in the name of simplicity. Then, ERM is probably the right answer.