Identifying the dampening foam used in keyboards
Identifying the dampening foam used in keyboards
It seems you're questioning whether a lack of electron buildup indicates good electrical conductivity, and whether your concerns about ESD risks are valid. Additionally, you're curious about the material composition of the HyperX Alloy Origins baseplate—exterior aluminum versus interior plastic—and its potential impact.
I observed that removing a section and pressing it onto the carpet did not draw in any hair strands, yet placing the entire foam roll over the carpet and placing hair near it caused the hairs to move toward the roll. It won’t attract hair simply by proximity like a magnet, but only when hair lands nearby. I think this suggests the foam isn’t conductive, though it could still generate ESD. When my finger approaches the stuck hairs, they shift slightly. What does that imply about static on my finger?
I believe the material could be EVA foam, as mentioned by a friend who used it for cosplay. The texture matches what you described. If this applies, is 4mm considered too thick for padding? Would contact with the PCB be problematic, or is that acceptable? At what thickness would it become too thick?
It seems the foam might accumulate a charge. But considering the different routes to ground through the keyboard (as explained by @Eximo) and your fingers on the keyboard, any buildup shouldn't be an issue. I've accidentally discharged my systems a few times using wired keyboards. After rebooting, everything was fine. I often touch my PC case or file cabinet before typing, even though I mostly use wireless (BT) devices.
Avoid disrupting sound absorption or electrostatic discharge protection.
Ty, I'm not entirely clear on the elements involved in grounding, but I'll check and return when I have more clarity.
A typical comparison used to clarify current movement is water flow. The main idea to grasp is potential difference, or voltage. When you have a completely full bucket and a half-filled one next to each other, no movement occurs (6 volts and 12 volts). But if you link those two buckets at the base with a tube, water will move from the full one to the half until they reach the same level (9 volts and 9 volts). Ground, or the shared connection, remains at zero in any circuit. It is always the path of least resistance to zero.
Static electricity produces extremely high voltages that can harm low-voltage systems at a microscopic level. Having a ground plane ensures any discharge travels straight to zero, not through sensitive electronics. This is why ESD-safe materials need to be conductive and more so than typical electronic components. Grounding also serves as a safety precaution: any dangerous short will connect to the ground, avoiding contact with people who have higher resistance than the grounded path. This applies to both electronics and household appliances. In devices like PC power supplies, the input is around 170 volts DC, which drops to 12V, 5V, and 3.3V after conversion. The numbers are simplified for design purposes; real electric fields behave differently, but the principles still hold.
Water = current, buckets = capacitors, resistors = different tube sizes, transistors (similar to valves). Early vacuum tubes were even called valves.