Garage Door Opener
Did you know that the original overhead garage door opener was invented all the way back in 1926? Some kids today probably don’t even think we had electricity back then! G.C Johnson of Indiana first came up with the idea. Truth be told, garage door openers were not really popular until after World War II. After WWII the Era Meter Company in Chicago offered a simplified version that used a keypad either in the garage or just outside of the garage. Obviously, remote garage door openers were still a little ways off. Remotes were popularized around the year 1960. There’s the general history, but that leaves a more significant question…
How They Work
Garage Door openers are the electrical motor that operates the garage door itself either with a rope or a chain. The garage door glides or rolls along garage door tracks while being pulled up or slowly let down by the garage door opener. However, the garage door opener motor does not do the majority of the work. The garage door springs do the real heavy lifting. This is usually a torsion spring, it counters the weight of the garage door against gravity. Without this spring, it would be near impossible to open or close the garage door safely. Most garage doors weigh better than a hundred pounds. A motor capable of lifting that would be a lot bigger than most garage door motors are.
Sending The Right (And Wrong) Signals
Garage door openers have had remotes for several decades now. Which is good, because they haven’t always worked flawlessly. Most garage door openers can be operated with your phone these days. That doesn’t leave a lot of room for error. But back in the day, there was a possibility that you could open your neighbor’s garage door with your remote! This, unfortunately, also mean thieves could “hack” your garage door opener and break in that way. When opener remotes first came out, they used simple radio signals. Some garage door openers would even open at random due to Am or FM radio signals. Needless to say, garage door openers today are not only far more secure but actually, provide a better layer of security. They can act as the sensor for a home security system to detect home invaders.
The Insides Of A Garage Door Motor
- Motor & Gears: The motor is typically about a 1/2-hp, 6-amp machine hooked to a 120-volt outlet—that’s all it takes to overcome the inertia of a stopped door. The machine also slows a door in transit, preventing it from crashing into the garage floor.
- Drive Guide: This track (aka the T-rail) guides and shields the chain, screw or belt as it moves the door open and closed. It connects the operator to the trolley, which in turn is connected to the door.
- Height Adjustment: Operator settings determine the distance the door travels. The machine kicks in to arrest the door’s motion or to make adjustments if a door isn’t opening or closing completely. The force of the door’s motion can also be adjusted so the door stops moving if grabbed.
- Inverter & Battery: To allow smaller, more efficient motors, most garage-door operators use DC current. An inverter switches household AC power to DC, which is also used to charge a battery backup system that kicks in when the power is out.
The motor itself runs off of a simple electrical supply wired from the home, and some have battery backups in case of a power outage. The electricity is used by the motor to turn gears inside the motor that either loosen the slack of the chain/rope or wind it up. Though all newer garage door openers use a chain drive Garage Door Opener, Belt Drive Garage Door Opener, or a screwdriver. The screw-drive garage door openers are a new concept and are much more efficient. They still operate on the same fundamental principle but use less electricity, and they’re quieter. Most openers use a half-horsepower motor, but some use a one-horsepower motor. There is your intro to garage door openers! If you’re having trouble with your electric garage door opener, then check out some of our articles on them.
The cheapest and oldest technology, the bike-chain-style chain sits slightly slack when the door is open—at least 1/2 inch above the bottom of the T-rail. The chain makes a racket, but maybe that’s a good thing when your teenagers are sneaking out.
A continuous threaded shaft connects the operator to the trolley, and its arm reaches for the door. Its threads require biannual lubrication with silicone, and it wears out the trolley more quickly than the other options. But the screw is the Goldilocks drive—median price and noise level.
Among the quietest (and costliest) drive options, the belt’s Kevlar polymer body is molded into nubby teeth on one side. These rotate through a gear on the operator’s top to pull the trolley.
How It Works: Garage Door Opener
The garage door dies some time during its 13,476th operation, while it’s being closed. It goes out without much drama—there’s no audible snap as the torsion spring breaks, no parts dangle loose in telltale failure, and the motor sill lights up, strains and stops. Maybe its decline started that day you closed the door on the Buick bumper, or maybe during the last big freeze, when ice swelled the door sections. Or maybe it was just the mechanism’s time. The average American garage door opens and shuts 1500 times a year, and this torsion spring—rated for 10,000 cycles—was positively geriatric in garage-door years. Regardless, you’re in the market for a new system. Here’s everything you’ll need to know.