Simple, rapid and low-cost assembly methods of a LED lamp are provided. The frit can form multiple closed-loops to prevent crack propagation. The wheel contains an embedded magnetic element such that as the wheel turns, which magnetically provides rotational position information to an adjacently-mounted sensor chip, which is able to determine, magnetically, the position of the wheel. The method comprises the steps of sensing a voltage by a tracking coil, providing the voltage to a center error generation circuit, generating a center error signal from the center error generation circuit based on the voltage and utilizing the center error signal to center the light beam.