Rise time

About: Rise time is a research topic. Over the lifetime, 4748 publications have been published within this topic receiving 47512 citations.

Design and Construction of a Trigger Generator Based on Pulse Transformer for Spark Gap Switch

Abstract: A two-electrode graphite spark gap switch is used as the main discharge switch and triggered by a reliable trigger generator in a pulsed-power conditioning system. The trigger generator based on resonant charging of a pulse transformer is constructed. An appropriate ratio can be obtained when using resonant charging based on a core-type pulse transformer. The charging time is dependent on the leakage inductance and the capacitance of the primary and secondary capacitors. The stray resistance and magnetizing inductance of the resonant charging circuit have an impact on ratio and energy transmission efficiency. A dry-type pulse transformer with a load of 1.08 nF, an output voltage of more than 130 kV, and a winding ratio of 65 is presented. A self-breakdown three-electrode output switch is used to shorten the rise time of the output impulse. The deviation of the self-breakdown voltage of the self-breakdown three-electrode output switch is much smaller than that of the self-breakdown two-electrode output switch. It assures that the trigger generator has a low jitter of output impulse when a lot of energy modules work simultaneously. The output impulse of the trigger generator with a peak value of more than 120 kV and a rise time of less than 30 ns can trigger the two-electrode graphite spark gap switch reliably.

10 kV SiC BJTs — Static, switching and reliability characteristics

Abstract: Open-base breakdown voltages as high as 10.5 kV (91% of theoretical avalanche limit and 125 V/μm), on-resistance of 110 mΩ-cm2 close to the unipolar limit of 94 mΩ-cm2, and current gain as high as 75 are measured on 10 kV-class SiC BJTs. Monolithic Darlington-connected BJTs fabricated on the same wafer yield current gains as high as 3400, and show Si BJT-like output characteristics with a differential on-resistance as low as 44 mΩ-cm2 in the saturation region and a distinct quasi-saturation region. Switching measurements performed at a DC link voltage of 5 kV and collector current of 8 A feature a collector current rise time as low as 30 ns during turn-on and collector voltage recovery time as low as 100 ns during turn-off. Very low turn-on and turn-off switching energies of 4.2 mJ and 1.6 mJ, respectively, are extracted from the switching transients, which are 19 and 25 times smaller than the corresponding switching energies reported on 6.5 kV Si IGBTs. When turnedon to a short-circuited load at a collector bias of 4500 V, the 10 kV BJT shows a temperature-invariant, withstand time in excess of 20 μs. Leakage currents <; 1μA (system limit) are measured, even after 234 hours of operation under a DC collector bias of 5000 V at elevated temperatures.

Embedded sensor fusion and moving-average filter for Inertial Measurement Unit (IMU) on the microcontroller-based stabilized platform

Abstract: Sensor Fusion (Complementary and Kalman filters) and Moving Average filter are implemented on an Arduino microcontroller based data acquisition of rotation degree from Inertial Measurement Unit (IMU) sensor for stabilized platform application. Stable platform prototype is designed to have two degrees of freedom, roll and pitch rotation. Output data from gyro and accelerometer were combined to take the advantage of each sensor. Digital filter algorithm was embedded into microcontroller programming. This paper analyzes overshoot percentage, rise time, and data series smoothness of Sensor Fusion (Complementary and Kalman filter) and Moving Average filter response in IMU data acquisition from step input of 20-degreerotation. Moving-average filter resulted in the smallest overshoot percentage of 0% but produce theslowest responsewith 0.42 second rise time. Overall best results are obtained using Complementary filter (alpha value 0.95) by overshoot percentage of 14.17%, 0.24 second rise time, and 0.18 data series smoothness.

Charge Pump Improvement for Energy Harvesting Applications by Node Pre-Charging

Abstract: This brief proposes a simple but effective strategy to improve wake-up operation in energy-autonomous systems which exploits Charge Pump (CP) circuits to boost voltage directly from energy harvester generators. By means of few auxiliary diodes and parasitic junctions, the CP is managed to retain the charges in the pumping capacitors when the harvesting power source is not able to feed the system, thereby reducing the rise time and input energy demand during the start-up phase. Simulation results using a 65-nm CMOS technology confirm the potentialities of the proposed strategy and show a reduction of the rise time and the input energy higher than 20% as compared with the traditional topology.

Dc motor speed control using pid controller

Abstract: The PID controller is placed in the forward path, so that its output becomes the voltage applied to the motor's armature .the feedback signal is a velocity, measured by a tachometer .the output velocity signal y (t) is summed with a reference or command signal R (t) to form the error signal e (t). Finally, the error signal is the input to the PID controller. Before examining the input-output relationships and design methods for the PID controller, it is helpful to review typical characteristics observed for the velocity response of a DC motor to a step voltage input. Different characteristics of the motor response (steady-state error, peak overshoot, rise time, settling time, etc) are controlled by selection of the three gains that modify the PID controller dynamiclly. This is discussed in detail below .the PID controller is defined by the following relationship between the controller input e (t) and the controller output u (t) that is applied to the motor armature: ∫ × + × × + × =