Have you ever wondered how an elevator (or stair lift) knows which floor it’s on? We have, too! It all comes down to one of the fundamental—and most fascinating—parts of an elevator: the selector system.
So, what is an elevator selector, and how does it tell the system which floor the car is on? We’ll get to that. But first, let’s look at how lifts, including home lifts (also called shaftless home elevators), know when to stop and where to go. Then, we’ll dive into the more complex topic of home elevator selectors.
The Difference Between a Lift and an Elevator
In U.S. terminology, lifts are generally simpler than elevators. Instead of using a complex selector system, lifts rely on slow-down switches, limit switches, and other microswitches to determine when they’ve reached the end of their path.
Take a basic straight stair lift, for example. You press the directional control to move up or down. If it’s already at the end of the rail, it will only move in the opposite direction. (Don’t worry, it won’t go flying off like in the movie Gremlins.) The same applies to garage wheelchair lifts and shaftless home elevators: press and hold the control button to move in your chosen direction.
As you ride a lift, the carriage, platform, or lift car encounters small microswitches that signal when to slow down and when to stop. Older stairway lifts and wheelchair lifts might lack a slow-down switch, but most modern lifts and home elevators include one for a smoother, safer ride.
How the Elevator Knows Its Location
Home elevators, as well as commercial elevators, require a more advanced operating system than basic lifts. To determine their location within the shaft, elevators use the above-mentioned device called a selector. This small metal box, filled with electronics, reads magnetic patterns placed along metal plates or magnetic tape running from the top to the bottom of the shaft.
Since the selector is mounted outside the elevator car, you typically won’t see it or the magnets (unless you’re in a glass elevator). As the car moves, the selector reads different magnet patterns to determine its position. This data is sent to the elevator controller, the ‘brains’ of the elevator, which integrates it with safety mechanisms to ensure smooth operation.
For example, if the car is at the top floor, the controller ensures it can only move downward. Likewise, at the bottom, it will only allow upward movement. The controller also regulates speed and direction, ensuring the elevator operates safely and efficiently.
The Functionality Behind the Complexity
Why do lifts rely on simple microswitches while elevators use a more complex selector system? The key difference comes down to functionality. Elevators, including residential ones, need to handle more floors and additional complexities.
For example, imagine an elevator with two sets of doors — one on the front and one on the rear — serving six stops: three on one side of the shaft and three on the opposite side. The system must not only recognize which of the six levels it’s on but also determine which set of doors to open. Achieving this with just microswitches would be far more complicated and less reliable than using a selector system.
Simply put, the selector system is built to handle these challenges efficiently, safely, and reliably. Using microswitches alone would require extensive modifications. Think of it like this: You could use a minivan as a makeshift pickup truck, but if a truck is available, it’s far more practical to use the right tool for the job.
Arrow Lift Has the Details Covered
If you’re an engineer or tech enthusiast, this might have been a fascinating deep dive! But if you’re a typical home elevator customer, don’t worry. Arrow Lift has you covered. With 40 years of experience, we handle all the technical and safety details, so you don’t have to.
We’ll help you find the best home elevator solution based on your home and needs. While you will have other choices to make, like your preferred design and model, you won’t have to worry about selecting a selector!
For more information on home elevator options, contact us anytime. And thanks for taking the time to learn more about how our elevators work!
