a prototype mechanical keyboard design based on inductive and capacitive sensing

project folder layout:

• cad - contains the kicad and autocad files for pcb and switch design
• datasheets - information about the mechanical and electrical components used
• jupyter - ipython notebook for the theory of operation
• layout - proposed eventual keyboard layouts
• scripts - help scripts for use with design
• spice - ltspice simulation source

the main driving idea behind this keyboard switch design is to to build an even more reliable beam spring like keyboard, that is a non conductivly sensed switch with a high lifetime. the main mechanism of failure of most capacitive switches is dirt and dust sensitivity,

a prototype mechanical keyboard design based on inductive and capacitive sensing

project folder layout:

• cad - contains the kicad and autocad files for pcb and switch design
• datasheets - information about the mechanical and electrical components used
• jupyter - ipython notebook for the theory of operation
• layout - proposed eventual keyboard layouts
• scripts - help scripts for use with design
• spice - ltspice simulation source

the main driving idea behind this keyboard switch design is to to build an even more reliable beam spring like keyboard, that is a non conductivly sensed switch with a high lifetime. the main mechanism of failure of most capacitive switches is dirt and dust sensitivity, which can be mitigated against by the use of a spacer. This however makes the capacitive mechanism useless, (too much distance at low voltages) to ensure the functionality of a such a mechanism I use an inductive pad as the sensing element, such that when a peice of silicon steel laminate is placed near the pad (with a protective spacer between!) the inductance, and hence the impedence of the circuit is changed. this of couse can be sensed by the controller.