Use LS7232 to make long-distance lead touch dimmer lamp

The circuit of a long-distance lead touch dimmer lamp made with LS7232 ASIC is shown in Figure 2-15. The right part of the dotted line in the figure
is the newly added remote touch control part, and the left part is the improved circuit in Figure 2-14.
    The working voltage of the integrated circuit is supplied by resistor Rl and capacitor C2 after step-down, VD1 voltage stabilization, VD2 rectification, and C3 filtering
. A DC voltage of about 15V can be obtained at both ends of C3. Capacitor C1 and inductor L are used to eliminate high-frequency interference radiation generated by the thyristor switch , so as not to affect the normal operation of other audio and video equipment. Resistor R2 provides a 50Hz AC synchronization signal
to the integrated block after current limiting .
C4 is used to filter out spike interference. c5 is PLI. filter capacitor. Pin 2 of the integrated block
is connected to power vss when not in use. VD3 plays the role of isolation and provides trigger signal to vs. The resistance of resistor R3 will affect the sensitivity of hand touch
, and can usually be selected between 1~4.7MO. M1 is a close-range touch electrode near the switch. Touching M1 can
turn on and off the light and dim the light.
    The long-distance long lead touch part is shown on the right side of the dotted line in the figure. When a human hand touches M2, the AC signal leaked from the human body passes through
the resistor Rl0 and is amplified by the transistor VT, and is sent to the 6-pin SL end of the integrated block for touch control. It can be seen from the figure that the
lighting, extinguishing and dimming of the electric lamp H can be controlled by the touch pads M1 and M2 at the same time, and the distance between M1 and M2 can be very far, with
only two leads in the middle.