Abstract: A threshold detection circuit may sense when current between a power supply and a load reaches a current threshold level. The threshold detection circuit may include a transistor in series with the load; a feedback circuit that causes the voltage drop across the transistor to be constant while the transistor is conducting current between the power supply and the load; a constant current source that delivers a constant current into the load; and a comparator that indicates when the voltage drop across the transistor falls below a voltage threshold level.

Abstract: An efficiency measuring circuit may measure the efficiency of a DC-DC converter having a switching inductor with an internal DC resistance and a plurality of electronic switches that control current through the inductor. A duty cycle circuit may measure the duty cycle of current flowing through one of the electronic switches. A current sense circuit may measure the current flowing through one of the electronic switches. An inductor voltage sensor circuit may measure the voltage across the inductor. A computation circuit may compute the internal DC resistance of the switching inductor based in part on the duty cycle measured by the duty cycle circuit and the current measured by the current sense circuit. The computation circuit may also compute the efficiency of the DC-DC converter.

Abstract: A dynamically-compensated controller may generate a switching signal for a DC power supply. The controller may include a feedback circuit having a first analog-to-digital converter and a separate analyzer circuit for generating information indicative of performance characteristics of the feedback circuit based on information about the results of a test perturbation signal at an output of the DC power supply. The analyzer circuit may include a DC removal circuit configured to substantially filter out the DC component of the results of the test perturbation signal at the output of the DC power supply, a frequency translation circuit configured to translate the frequency of the filtered signal to a frequency that is lower than the frequency of the test perturbation signal, and a second analog-to-digital converter different from the first analog-to-digital converter that is configured to generate a signal representative of one or more of the characteristics of the filtered signal.

Abstract: An efficiency measuring circuit may measure the efficiency of a DC-DC converter having a switching inductor with an internal DC resistance and a plurality of electronic switches that control current through the inductor. A duty cycle circuit may measure the duty cycle of current flowing through one of the electronic switches. A current sense circuit may measure the current flowing through one of the electronic switches. An inductor voltage sensor circuit may measure the voltage across the inductor. A computation circuit may compute the internal DC resistance of the switching inductor based in part on the duty cycle measured by the duty cycle circuit and the current measured by the current sense circuit. The computation circuit may also compute the efficiency of the DC-DC converter.

Abstract: Methods and apparatus for sampling an input voltage and apparatus incorporating the same are disclosed. An input voltage sampling apparatus includes a voltage sampling circuit coupled to the input voltage and configured to produce a sampled input voltage at an output terminal, and a voltage charging circuit coupled to the voltage sampling device and producing a first charged voltage on a first charged voltage output terminal and a second charged voltage on a second charged voltage output terminal. A voltage charging enabling circuit is coupled to the voltage charging circuit, the voltage sampling device via the first connection, and a power supply voltage. Further, the input voltage sampling apparatus includes a control circuit coupled to the voltage sampling circuit, the voltage charging circuit, and the power supply voltage, ground, third and fourth pulse signals. The first and third pulse signals are non-overlapping with the second and fourth pulse signals.

Abstract: A safety edge for an electrically operated door includes a female housing strip adapted for attachment to an edge of a door and a male actuator strip. The female housing strip has an interior cavity in which is positioned a first electrical contact. The male actuator strip has a second electrical contact. The male actuator is telescopically received in the female housing. The male actuator strip is movable between a first position in which the second electrical contact is spaced from the first electrical contact and a second position in which the second electrical contact engages the first electrical contact.