A novel touch switch desk lamp circuit

Recently, the author drew the circuit of a new touch-type desk lamp based on the actual thing, and now provide it for your reference. The circuit is shown in the figure. It controls the brightness of the bulb in four levels. If the bulb does not light up after powering on, gently touch the metal shell of the lampshade for the first time. The light bulb will emit low-brightness light, touch it for the second time to emit medium-brightness light, touch it for the third time to turn it on to full brightness, touch it for the fourth time to turn off the light bulb, and cycle in sequence. The common fault of this circuit is that the bidirectional thyristor 97A6 is broken and the contact between the metal shell of the lampshade and the touch input terminal of the circuit is poor. When the author debugged this circuit, the TT6061 used the GS6061 generation, the 1N4004 used the 1N4007 generation, and the other components were the same as in the picture. It has been verified that the circuit works reliably and can achieve the functions described in the article. However, the bidirectional thyristor is easily damaged. It is recommended that readers connect a resistor and capacitor in series to both ends of the thyristor in parallel when making a protection circuit.