deskthority

After enquiring about what reed switches Andrew Nelsen used in his pipe organ (Elec-Trol KA1017-0004), he noted that one of the things he likes about them is that:

"they have about 80 thou hysteresis -- thus the contact is certain, and bounce-free"

That was news to me, but I tested a couple of my B2R switches and one of them did have distinct hysteresis, while the other seemed not to (or if so, it's not reliable). I just tested a Pendar SIL1101 switch and that's got very distinct hysteresis. SIL1101 also has arm dampers, as Omron or Logitech would later reintroduce in the Romer-G.

The non-keyboard reed switches that I know do have hysteresis as well. That doesn't make them inherently bounce-free as far as I know.

From what little I've seen said of it, hysteresis seems to be about preventing the operator from "teasing" the switch. I wasn't aware that it was meant to prevent contact bounce (which it can't) but rather it stops the switch from repeatedly engaging and disengaging. I've never understood that either, as I've never had any issues with non-hysteresis designs such as MX Red or Futaba MR-6C.

Some of Jacob's force curve graphs show press/release points (presumably only those where loose, conductive switches were used) so in time we should get a clear idea of reed switch hystersis from those.