Diode dimmer switch circuit

In the above example, we used a 1×3 dual-control pull-wire
switch. If the reader purchases a pull-wire switch as small as this,
other circuits can be used to achieve the same purpose of disc lighting. It is controlled by two ordinary switches Sl and S2: when Sl and S2
are both closed, the lamp E lights normally: SI remains closed, S2 is
open, and the lamp E emits dim light; if Sl is opened, regardless of whether S2 is closed
or not, the lamp E emits dim light. E are all off.