167 results about "Test pulse" patented technology

Systems and methods for immobilizing a target such as a human or animal with a stimulus signal coupled to the target via numerous electrodes select particular electrodes to use for the stimulus signal. Subsets of electrodes may be tested by applying a test signal and monitoring the energy or charge delivered during a prescribed time. If the delivered energy or charge using a particular subset of electrodes as indicated by monitoring test pulse amplitude suitably compares to a limit, then the particular subset is selected for applying the stimulus signal. A first stimulus signal may be applied to a first subset of electrodes to prompt movement of the target toward an electrode that, when better coupled to the target as a consequence of movement of the target will provide a more effective subset of electrodes for further stimulus. For example, a projectile with closely spaced electrodes may stimulate a burning sensation to attract the target to impale the target's hand on a rear facing electrode of the projectile. Use of the rear facing electrode and one or more of the closely spaced electrodes may provide a more effective stimulus circuit through tissue of the target.

A system and method for measuring the speed of a fan is presented. The duty cycle of a pulse width modulated (PWM) power signal may control speed of the fan. The fan may generate tachometer pulses used for monitoring RPM of the fan. Very low frequency test pulses may be generated and provided via a test signal multiplexed with the PWM signal to obtain tachometer pulses present even when the PWM signal is deasserted. The frequency of the test signal may be determined based on the duty cycle of the PWM signal and may be dynamically updated using frequency divider values stored in a user programmable look-up table. The tachometer pulses may be used to reset a flip-flop whose data input is held high and a down counter, which may be operated at a frequency slightly lower than the frequency of the test signal, with the output of the down counter clocking the flip-flop. The output of the flip-flop may provide recreated tachometer pulses to a pulse counter that counts the number of pulses within a determined period of time, providing a measured RPM of the fan.