Most dimmer switches I see in stores have an on / off toggle and also a slider to dim the lights. They look something like this:
I think their goal is that you can set the brightness at your preferred level, then switch the light off and on without changing that.
However, I want a dimmer switch that works more like this speaker knob: to turn it off, you twist it counterclockwise, reducing the volume all the way to the minimum, at which point there's a click as you pass from on to off. Turning it on is the reverse: click on, turn up to desired level.
The advantage here is that you never switch on the sound or the light and get surprised with a very bright or loud level; you always start at nothing and turn it up to the desired level. As a nice side effect for a dimmer switch, because you must consciously choose the light level every time, it's likely you'll stop before reaching maximum brightness instead of always defaulting to that, and thereby save power.
Is there a name for this kind of "toggle knob" dimmer switch so that I can search for one?