What is Hall Effect keyboard switch anyway?

Hall Effect illustration (Wikipedia)

Some of the keyboard related blogs recently mentioned Hall effect key switches.  It was not a term that I have heard for a while and have forgotten what it does.  After a little research, memories come flooding back.  Good and bad...  Anyway, Hall effect sensors or switches work because of a pretty cool physical phenomenon.

Basically the position of magnet (due to magnetic field) can affect a transducer voltage.  So, if the magnetic strength is known, then one can determine the distance of the magnet from the transducer by the output voltage.  Therefore, putting the two and two together, this sensor would make a very good analog keyboard switch.  Also, there are very few moving parts that may fatigue and break, thus Hall effect sensors are also very reliable devices.  So, it shouldn't be a big surprise in the sudden interest in this type of switch lately given the latest rage in analog keyboard.  The simplest resistance mechanics to a key press is a spring, therefore this technology seems well suited for a linear keyboard switch.  It's a pretty good match to what the gaming market desires.  There are some rumblings that keyboard manufacturers are going to bring some Hall effect keyboards to the market that caters to the booming gaming market.  However, it doesn't stop anyone from adding clicky emulations to the key switch.  So, perhaps some enterprising company will figure out how to do so.

Although the idea has been around for a long time, the recent interest in analog gaming sensors has resurrected interest in this kind of device.  However, Hall effect devices are more complex compared to a simple mechanical key switch.  So, in a cut-throat market, price would be a very important factor as well.  So, we will see how well the gaming market adapt to this type of switch or it is just needless complications.  I think there's room for analog keyboards for specific gaming niche.  We will have to figure out a purpose for these wonderful devices outside of that for something this cool to become mainstream.