Abstract: A controller for a power converter includes conduction detection circuitry and a variable reference generator. The conduction detection circuitry is coupled to generate a conduction signal representative of conduction times that an input signal is above a threshold value. The variable reference generator is coupled to receive the conduction signal and configured to generate a count value in response to a first conduction time of the conduction signal. The variable reference generator is coupled to output a reference signal in response to the count value and in response to prior count values stored in the variable reference generator.

Abstract: This relates to an apparatus and method for selectively adding a capacitance to an input of a power converter of a power conversion system. A power conversion system may selectively introduce additional input capacitance in response to an input voltage. In one example, a power conversion system operates in a first mode (dimming mode) and engages a selective capacitor circuit to introduce additional capacitance to an input of a power converter. In a second mode (non-dimming mode), the power conversion system disengages the selective capacitor circuit from the input of the power converter.

Abstract: A flyback power supply method and apparatus is disclosed. An apparatus according to aspects of the present invention includes an energy transfer element having a primary winding and first and second output windings. The first and second output windings are coupled to produce first and second output values, respectively. A primary switch is coupled to the primary winding. A control circuit is coupled to the primary switch to regulate a sum of the first and second output values. A steering circuit having first and second output switches is also included. The first and second output switches are coupled to the first and second output windings, respectively, to regulate a ratio of the first output value to the second output value. The first output switch is coupled to block current through the first output winding and the second output switch is coupled to block current through second output winding. At least one of the first and second output switches is coupled to be closed when the primary switch is opened.

Abstract: A flyback power supply method and apparatus is disclosed. An apparatus according to aspects of the present invention includes an energy transfer element having a primary winding and first and second output windings. The first and second output windings are coupled to produce first and second output values, respectively. A primary switch is coupled to the primary winding. A control circuit is coupled to the primary switch to regulate a sum of the first and second output values. A steering circuit having first and second output switches is also included. The first and second output switches are coupled to the first and second output windings, respectively, to regulate a ratio of the first output value to the second output value. The first output switch is coupled to block current through the first output winding and the second output switch is coupled to block current through second output winding. At least one of the first and second output switches is coupled to be closed when the primary switch is opened.

Abstract: A grinding pin (53) for notch grinding is provided. The grinding pin comprises a cylindrical region of formable grinding material and in which is formed a groove (18) for forming a notch. The length of the cylindrical region is such that further grooves (20) can be formed therein as each groove becomes too worn to form a notch.