The present invention comprises a rectifier-filter circuit, an active power factor correction, an oscillating circuit, a boost circuit, a tube circuit, an internal power, a sampling circuit, a micro controller unit, a detecting circuit, and a power switch to regulate the brightness of a lamp. In a first instance, the carrier frequency can include an offset for each radar system. The outer diameter of the piston ring mounted on in the annular groove is larger than the diameter of the piston body, so that the piston ring contacts with the inner wall but the piston body has no contact with the inner wall while the piston device moves reciprocally at the axial direction of the cylinder. The resistance generating mechanism may include at least two spring mechanisms and provide feedback to the user that the inserted article may be too thick.