Touch-type incandescent lamp dimming switch circuit

This electronic dimming switch controls the dimming and on/off operation of incandescent lamps by touch. Each time the electrode is touched, the light brightness changes in four gears: slightly brighter, brighter, brightest, and off. The dimmer power supply is 180-240V AC; the operating frequency is 50/60Hz; the load power is 60-120W. This dimmer switch is widely used in touch dimming lamp products of incandescent lamps and table lamps.

Figure 7 is a typical application circuit schematic. It consists of SH-04 dimming IC and a few external components. When the first touch is made, the conduction angle of the bidirectional thyristor SCR is 170 degrees, and the incandescent lamp is in a slightly bright state. The second touch. The conduction angle of the SCR is 86 degrees, and the incandescent lamp is in a brighter state. After the third touch, the conduction angle of the SCR can reach more than 121 degrees, and the incandescent lamp is in the brightest state. After the fourth touch. The internal divider stops counting, the ⑧ pin of the SH-04 has no output, the SCR is turned off, and the incandescent lamp goes out. The circuit controls the brightness and on/off of the incandescent lamp in the above sequence.

In addition to dimming incandescent lamps, this dimming control circuit can also be used for temperature and speed control of daily electrical appliances such as electric soldering irons and electric blankets. When making it, you only need to change the incandescent lamp to a 220V AC socket and change the touch control to key control, and it will become a multi-purpose dimming and temperature control controller.