Magnets? In My Switches??

The two worlds of vintage and modern mechanical keyboard switches couldn’t be more different from each other. Prior to the 1990s, any company attempting to make their own keyboard likely invented their own switches from the ground up with a wide array of crazy ideas tossed in for good measure. Rather than the fairly homogenously designed rainbow of switches that are available today, this resulted in basically every other switch having unique structures, mechanisms, and even manufacturing processes that set them apart from every other offering out there. And, whether or not this is easy to believe, this largely was the status quo for mechanical keyboard switches up to the point of Cherry’s patent expiration. (This is of course with the community-favorite exception of Alps SKCL and SKCM switches, which were at least a tiny bit more widespread than most other switches at the time.)

Since the lapsing of Cherry’s patent on the MX-style switch design in 2014, the vast majority of mechanical keyboard switches have shifted to copying the ‘MX-style’ footprint. While this arguably has allowed for the community that has brought all of us here to this article to blossom and flourish, it certainly has also led to a bit of repetition and stagnation with respect to switch design in recent years. Irrespective of incremental takes on the MX footprint that have been popping up so far in 2024, the underlying ‘complete-the-circuit’ style technology of MX-style switches still remains the de facto standard. At least it hasn’t been challenged until now as we are on the cusp of witnessing the slow and steady climb back to relevance of Hall Effect switches – a contactless, electromagnetic-based switch design first introduced by Honeywell all the way back in the 1960s. Since there’s a non-zero chance that these Hall Effect switches will become compatible with a board near you soon, it's probably a bit important to know something about them!

Now, I’ll be the first to acknowledge that any switch boasting technology that is “contactless” and can yet still be powered by the “electromagnetic force” might as well be marketed as being magical to most people. While the electromagnetic force is a bit magical in its own respect, I promise it's not nearly as hard to understand how Hall Effect switches work when compared directly to the common MX-style switches we know all about. Normal, MX-style switches don’t use any electromagnetic force but instead rely on two metal leaves inside the bottom housing of the switch connecting or separating to open or close a circuit connected to the PCB. Working in the opposite direction as that is the way that PCBs for MX-style switches are programmed when the stem is pressed into the switch, it separates the two leaves, breaks the flow of electrons through the circuit, and then registers as a keystroke. When you let go, the leaves re-contact and establish the flow of electrons. Think of it almost like an ‘on’ or ‘off’ switch without an in-between.

In contrast, Hall Effect switches do not have any metal contacts and instead operate via a strong magnet embedded in the stem of the switch. When the stem is pressed in, the magnet is pushed closer to the PCB until it begins “pushing” electrons in circuits within the PCB with some amount of force. In the opposite way, as the stem is released, the magnet moves away and doesn’t “push” on the electrons nearly as hard. This “pushing” of the current of electrons via the magnetic field from the magnet is quite literally known as the ‘Hall Effect’ and is what Hall Effect PCBs are designed to look out for. Rather than just completing or breaking a circuit, the PCBs in Hall Effect keyboards are programmed to constantly sense how strong the current of electrons is affected by the magnet, with a pre-programmed force being chosen in the PCB’s software as the point of actuation. While that all sounds like it’s a bit overcomplicated for no particular reason, that couldn’t be further from the truth at all…

Aside from being able to flex your keyboard having more complicated technology than traditional MX-style builds, there are quite a few potential benefits to owning and using Hall Effect switches. Though, like all good things in keyboards, they do come with their fair share of tradeoffs. For one, since the PCBs designed around the Hall Effect have an arbitrarily programmed force that is considered the point of actuation, some PCBs allow you to directly program the point in the downstroke at which the switch is actuated, meaning you could pick 25%, 50%, or even 78% of the way into the switch’s downstroke to be where it actuates. This is, of course, something you can’t change or modify meaningfully in MX-style keyboards. Also, since Hall Effect switches are contactless and don’t have metal leaves, there are often fewer points for switches to scratch, squeak, or produce any other weird noises that may ruin your MX keyboard build.

All of that in mind, though, Hall Effect switches do require specific PCBs in order to be used, and there are currently no dual-compatible PCBs that work for both MX and Hall Effect style switches. Some companies that sell keyboard kits, like Matrix Labs and Geonworks, are just now beginning to offer PCBs that are Hall Effect compatible and fit in cases they’ve previously only made with MX-compatible PCBs. Another benefit of this most recent iteration of Hall Effect style switches is that all of them are being made by manufacturers that predominantly use MX keycap-compatible stem mounts. This means that as Hall Effect switches become increasingly popular, you won’t have to buy separate sets of keycaps only for your Hall Effect keyboards!

While Hall Effect switches are just now starting their climb back to relevancy, there’s no doubt that we will start seeing more and more of them in the coming years – both in prebuilt boards and custom-built keyboards. As of the time of writing this article, I know of at least 50 different Hall Effect switches available out there, and with major brands like Kailh, Outemu, and Gateron all giving their take on this “new” technology, I imagine we’ll see many more to come very soon. So, if you’re in the mood to switch things up a bit and try a new keyboard technology, consider keeping your eyes out for Hall Effect compatible keyboards, PCBs, and switches in the coming months! Or, if you want to stick a little bit closer to home and enjoy the warm, comforting platform that is the classic MX-style, consider reading up on some of my other switch articles here on Kinetic Labs, such as ‘An Intro to Frankenswitches for Mechanical Keyboards’ or ‘Keyboard Switch Leaves Explained’!