A design structure for a Duty Cycle Correction circuit is provide in which pairs of field effect transistors in known DCC circuit topologies are replaced with linear resistors coupled to switches of the DCC circuit such that when the switch is open, the input signal is routed through the linear resistors. In accordance with one implementation, a method comprises providing, using at least one processor, instructions to display an advertisement together with a user interface on a first device, the user interface including a text entry field. Alternatively, a light sensor, such as an infrared sensor located on the inner surface of the lens cap, detects illumination from the lamp to sense insertion of the lens cap over the lens and to signal the illumination controller to turn off the lamp. A large-diameter piston head may be fixed to the outer end of the torque-compensating piston and slidably mounted within a cylinder defined at the housing end opposite the pump head.