Contents
What are voice coil motors?
Voice coil motors (VCM) or voice coil actuators (VCA) are non-commutated DC linear actuators that consist of a single-pole permanent magnet and a copper coil. VCMs are two-lead, single phase motors that do not require commutation, resulting in simple operation.
What is a linear voice coil?
A linear voice coil actuator is ideal for short stroke (typically less than 2 inches) closed loop servo applications. Its compact size allows it to fit into small spaces. It has very low electrical and mechanical time constants. The low moving mass allows for high accelerations of light payloads.
What is a voice coil used for?
A voice coil (consisting of a former, collar, and winding) is the coil of wire attached to the apex of a loudspeaker cone. It provides the motive force to the cone by the reaction of a magnetic field to the current passing through it.
Is a voice coil a solenoid?
A voice coil generates a force based on an interaction of a current carrying conductor in a permanent magnetic field. A solenoid generates force based on an electromagnetic field that is created by a current carrying conductor.
Is a bigger voice coil better?
Coil Size Matters Well, the larger you make the voice coil, the more power it can handle—but at the same time, it also generates more heat. Smaller coils can be a little more resonant, but larger coils tend to have better control. Some speakers have to have larger coils.
Does size of voice coil matter?
Coil Size Matters A smaller speaker like a 6″ speaker, often has a smaller voice coil than a larger speaker like the 8” version of the same speaker. Why does that matter? Well, the larger you make the voice coil, the more power it can handle—but at the same time, it also generates more heat.
What is the difference between an actuator and a solenoid?
Voice coil actuators are typically used in focusing applications, oscillatory systems, mirror tilting, and miniature position control. Solenoids consist of a coil that is contained in a ferrous steel housing and a movable steel slug or washer.
What’s the difference between a relay and a solenoid?
Solenoids are a type of relay engineered to remotely switch a heavier current (typically ranging from 85-200 amps). market, the term solenoid generally refers to a “metal can” type, whereas a relay typically refers to the standard “cube” style relay.
How does a voice coil actuator work?
Voice coil actuators are a type of direct drive mechanism that provides extremely precise positioning over small displacements. Like linear motors, they work on the principle of a permanent magnet field and a coil winding. When a current is applied to the coil, a force is generated.
Why do voice coils have good force control?
Even without a feedback device, a voice coil actuator has good force control due to the fact that the force generated is directly proportional to the applied current. Voice coils draw current when holding a load in a fixed position, or in vertical applications when counteracting the weight of the load.
What kind of motor is a voice coil?
FIGURE 1. The moving-coil type of voice-coil actuator is widely used. A voice-coil actuator, also known as a noncommutated DC linear actuator, is a type of direct-drive linear motor. The term “voice coil” comes from one of its historically first applications: vibrating the paper cone of a loudspeaker.
When does a voice coil draw a current?
Voice coils draw current when holding a load in a fixed position, or in vertical applications when counteracting the weight of the load. In addition, when the coil moves rapidly, a back EMF is generated, which is proportional to speed, current, and magnetic field strength.