Difference between dim switch and dim button?

I never claimed that I already understood the electrical system behind it – quite the opposite! Hence the follow-up questions and my attempt to cautiously approach the topic. Responses dripping with sarcasm don’t help me, so better save yourself the trouble and me the time of reading them.

That you are a “Nackerpatzl” (probably an Austrianism, since we Germans have some gaps there) you probably said, but due to the further remark

Attention: I’m not really concerned with the electrics themselves or the wiring behind it, but in truth only with the look of the switch/button!

I spared myself from running a basic electronics seminar first. I must have overlooked the sarcasm. So now back to the basics?

Are only the rotary dimmers buzzing?

Simplified, dimmers are throttling valves in the current flow to the light sources. If they have a rotary control switch, they are usually rotary potentiometers that, in what I’d call the low-frequency speed range of dimming, tend to oscillate quite a bit. Such dimmers are one dimmer with a rotary knob. Step dimmers don’t have one circuit but as many as steps, and work accordingly cleaner, without jitter. If you have a knack for achieving a finely graded result with a rotary controller, you can count yourself among an absolute elite. The advantage of rotary controls is that they physically remain in the last position. The switch itself "remembers" the position. You can also control such a rotary pot "remotely," using pushbuttons.

(Maybe I should add that I am not talking about a KNX control system or similar, if that matters?) [...] I didn’t want to get into Alexa, RFID, thought transmission, or whatever else.

With a step dimmer, it’s best to leave the "remembering" of the last setting to a PLC and of course choose pushbuttons for both switching (on/off) and momentary (plus/minus, standby/wakeup) commands. For the PLC, these pushbuttons act practically as detectors of control requests, and the system can learn to distinguish users. When operated by user Gisela, they behave like switches, and the more tech-affine users Horst and Daniel distinguish them also by the duration of the press. The PLC can have profiles "Gisela / Horst / Daniel" stored and deliver each their preferred program. Which bus system you prefer and whether it is proprietary plays a subordinate role.

The question arises (as with so much in planning) from practical considerations: "I walk down the hallway and do this or that...". And in this case my consideration is: "I come from room A into room B carrying a heavy shopping basket and want to switch the light on with my elbow. Better rotary dimmer or pushbutton dimmer?"

Best is a PLC with pushbutton control elements and proximity sensors for the RFID chip on your keychain. Then you don't have to bother with moisturizing the skin on your elbow at all. If your hands are free and you want manual control, you can tap the switch (long = switch, short = push). The system always distinguishes between you and your wife (Wife Acceptance) as well as invited guests (Guest Acceptance) and burglars (Guest Rejection along with calm alert).

When my friend Daniel Düsentrieb visits his parents’ house and has his keychain, the house recognizes him and adjusts the lighting according to his habits. If he leaves his keychain in the car and has to ring the doorbell, the “light switches” are set to the Gisela mode of his mother. Father Horst gets the path illuminated to his evening beer. Although I am younger than Horst, I am tech-conservative and as an invited but not RFID-chip-owning worthy guest, I get the Gisela mode as well. Whether clueless user or nerd(s), the house loves everyone equally.

well, look, now you have learned what a (technical) Nackerpatzl is and I already know a bit more about dimmers ;) An honest thank you!!

I have to confess, I have never had a push dimmer "in my hand" to test it. In no hotel, not among my friends, work, etc. Hence also my indecisiveness when choosing. With rotary dimmers it looks only slightly better.

should I also admit now that SPS is a foreign word to me?! But it is simply not my world, sorry! I also don’t want any programming things like adjusting lights automatically to the time of day, switches adapted to users via RFID or similar. Light on, light off. Dimmer up, dimmer down. No KNX, smart home etc. The honest reason? I don’t want to deal with it. And besides, it costs me too much. Don’t get me wrong, I really admire people who know how to make their house “smart”!

Allow me, considering all the above, to ask the following questions: If we assume a "dumb" push dimmer (no SPS, KNX, smart home or similar behind it):
- I dim it to 80% for example and then turn it off by clicking. -> I turn it on again by clicking. Is it then at 80% or full 100%? Or does that depend on the manufacturer? (I assume, since there is no intelligence, it’s 100%?)
- How long does it take to dim from min to max approximately? There must be some middle ground between "quickly dim up/down" and "fine tuning".

The honest reason? I don’t want to deal with it. And besides, it costs me too much. Don’t get me wrong, I really admire people who know how to make their house "smart"!

In a free country, you may wait until your grandchildren find you spooky. Having the technology doesn’t force you to consciously use it. Daniel’s mother uses "like back when Helmut was still called Schmidt" these control elements in the retro look of the switches from back then. But when she talks to Daniel on the phone and says it’s getting dim for her, Daniel (two hours away by car) makes her light brighter without her having to get up. Gisela (68) is a good Catholic old-fashioned country girl who has nothing to do with the technical devilry. She doesn’t have to, the technology has gentlemanly fully internalized the Wife Acceptance Factor and lets her use the house like back in the day. Even with jagged metal apartment keys!

I have to admit, I’ve never had a push dimmer "in my hand" to test it. Not in any hotel, not among my friends, work, etc. [...] If we assume a "dumb" push dimmer (no PLC, KNX, smart home or similar behind it): - For example, I dim it to 80% and then switch it off by clicking. -> I switch it on again by clicking. Is it then at 80% or full 100%? Or does that depend on the manufacturer? (I assume, since no intelligence is present, 100%?)

Whether you have never dealt with such things or just never noticed it (there are of course also hotels with Gisela mode) we will not be able to clarify here. You will certainly find rotary potentiometer or push-activated dimmer switches in specialist shops, even currently, not only antique. I know rotary potentiometer dimmers only in such a way that there is a classic rocker switch around it (on=on, off=off) and the rotary position of the "dimmer" keeps the set brightness because the thing is only operated manually. For dimmers without rotary potentiometer, I can imagine that they reset fixed to 100% or can be set, for example, to 60 or 80 percent via DIP switches, and that Gira maybe has a different philosophy there than Berker. In a good specialist shop someone should be able to advise you which products suit you.

How long does it take to dim from min to max approximately? There must be a middle ground somewhere between "quickly dim up/down" and "fine tuning".

It feels like there is no delay at all, that the pushbutton recognizes whether you tap it or hold it down. The dimmed lamp reports success to you in real time. Gisela herself dims at the "light switch" and the dimmer "stops immediately" when she lets go. Daniel dims with his smartphone when visiting her (delay about 350 ms), Daniel at home (that is two hours away by car) has to reckon with possibly more than 800 ms delay when dimming Gisela’s light. Intercontinental, copper cables have incredible signal propagation times, but at your home between switch and bulb of course not. The dimmer itself has a very simple circuit, "processing time" you can fully neglect/exclude. To imitate the steplessness of a rotary knob, you will probably need a 64-step step dimmer. In the economy price segment, four or eight steps will probably be more common, but I have no idea about that. At Daniel’s, his parents’ and our customers’, stupidest control switches are installed and the "intelligence" is fully left to the PLC (= programmable logic controller). That is just another way and roughly about equal in price to installing sophisticated "switches" everywhere.

Thank you very much for the answers!