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switches

On this image one switch should be tactile, another latching, which is which?
I did some research, I asked AI and it told me that KEY2 is latching, but I found this answer suspicious and confusing.

The entire scheme for reference

All images from YX2811 datasheet.

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  • \$\begingroup\$ KEY2 looks to me to be a misdrawn symbol, possibly it was supposed to be a pushbutton switch. I don't know if there is an "official" symbol for a latching switch; I've only ever seen it called out as a note or specific part number. The YX2811 is showing up as an 8-pin package on a quick search, but 9 pins are enumerated on the schematic. \$\endgroup\$ Commented Nov 7 at 20:09
  • \$\begingroup\$ @vir, I have actual device, I bet pin 9 = pin 7. \$\endgroup\$ Commented Nov 7 at 20:23
  • \$\begingroup\$ The functions of the two switches should indicate which should be momentary and which should be latching. \$\endgroup\$ Commented Nov 7 at 20:27
  • \$\begingroup\$ @kelin - Thanks for adding that reference link. Unfortunately, despite the filename, it isn't a proper datasheet (but I realise it might be all that you have). I looked at that PDF and did not find any claim there that "one switch should be tactile, another latching" as stated in the question. Just to be clear, where are you seeing that claim? || Also, referring to your recent comment where you said: "I bet pin 9 = pin 7" From experience, if the 8-pin package has an exposed thermal pad on the bottom, then "pin 9" on the schematic may be that exposed pad. \$\endgroup\$ Commented Nov 7 at 20:30
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    \$\begingroup\$ @kelin you are confusing momentary with tactile ... a tactile switch has feedback, such as a click ... it could be both a momentary type or toggle type ... the two switches in your post are SPST and possibly a misdrawn SPDT ... both are probably the toggle type ... momentary switches use a different symbol \$\endgroup\$ Commented Nov 8 at 0:41

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  • Key1 is a standard switch (which you call "latching" but that's an unusual name).
  • Key2 is a momentary limit switch (which you call "tactile", but many switches are momentary, not just tactile switches). We can tell it's a limit switch because of that extra bar and circle on the left of the symbol. (Of course, it's possible the designer used the wrong symbol, and they really meant a pushbutton switch.)

The difference between a pushbutton switch and a limit switch is that a the pushbutton switch is pressed with a finger and a limit switch is pressed by a mechanical motion (e.g., a closed door).

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  • \$\begingroup\$ Interestingly, the KEY2 symbol in the question doesn't match those shown in IEC-60617 Symbol Preview - Limit Switches. I not sure which, if any, standard KEY2 is from. \$\endgroup\$ Commented Nov 8 at 9:21
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    \$\begingroup\$ The "latching" name is from AI translation, original document is in Chinese. But you are right, I experimented with actual device and found that KEY1 is positional, while KEY2 is a push button that switches state from ON to OFF and vice versa by each push. \$\endgroup\$ Commented Nov 8 at 13:04
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    \$\begingroup\$ BTW "tactile" is an official term, I've seen it in Wikipedia. It's just a button that clicks when you push it. \$\endgroup\$ Commented Nov 8 at 14:29
  • \$\begingroup\$ Yes, of course. But you asked what that symbol means; It means limit switch. It means momentary. It doesn't mean "tactile". Yes, that could be a tactile switch, but it could also be any other momentary switch. \$\endgroup\$ Commented Nov 8 at 21:05

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