Editing Force (section)

==Overview==
"'''Force'''" refers to the effort required to press a [[key]] on a keyboard. Broadly (as is the case with linear switches), the more force you apply to the key, the further it will depress. This is a hard notion for humans to grasp as it's not how we perceive the act of pressing switch. Since weight is a force (what you weigh is mass, not weight), stacking coins on a key will give you a clearer depiction of force. Placing a coin onto a key applies its weight to that key; applying weight to the key will compress the spring inside the key until the force within the spring (in lay terms you'd think of this as pressure) balances out the weight of the coin. The spring already has between 30–40 cN of force in it to begin with, so you will need to add a few coins before the key starts to descend. Although coin stacking is a controversial approach to measuring force, the thin, flat nature of coins makes them useful for the purposes of demonstration.

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File:Coin stacking demonstration.jpg | Keys depressed different amounts by different numbers of coins
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Linear switches will depress by the same amount each time an identical coin is added (after you exceed the preload). In other kinds of switch, not only does the force change by non-uniform amounts, but it can even decrease! A change inside the switch—such as one that causes a spring to disengage—will cause the switch to exert less force. When adding coins onto a tactile or clicky key, this change is observed by the key suddenly dropping all the way to the bottom. The force exerted by the switch will have decreased, so the coins now offer far more force than the switch, and the key will move downwards sharply due to the imbalance in force. Although the switch will typically reach that amount of force again, the momentum of the coins will override the force in the spring.