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Tag Archives: H-bridge

Designing a RC snubber circuit

Posted on September 8, 2013 by R-B Leave a comment

In applications including power electronics, reverse recovery effects are very common and can induce unnecessary high-frequency oscillations in the circuit. This application document from NXP semiconductors describes the design of a simple “RC snubber circuit” for suppressing the oscillations. The technique requires the extraction of the circuit parasitic capacitance and inductance, and has been illustrated well with an example in the document.

Reverse recovery effects in H-bridge

H-Bridge to drive white LED arrays directly from the AC mains supply

Posted on August 23, 2013 by R-B Leave a comment

The classical H-bridge circuit is widely popular in driving DC motors in robotics applications. This article talks about a novel application of the H-bridge circuit for driving white-LED arrays directly from the AC mains in full-wave current-limited mode to realize an excellent flicker-free, energy-efficient solid-state lamp. The circuit controls and maintains the LED excitation current in both negative and positive half cycles of the excitation voltage to a constant level by way of electronic switches operating alternately during the positive and negative excursion of the excitation voltage.

H-bridge circuit for driving white LED arrays

Lab 10: DC motor interfacing to PICMicro

Posted on January 11, 2011 by R-B 20 comments

Description

Perhaps one of the most entertaining things to do with an embedded microcontroller is to get it to actually move something. Three very popular devices used to “make things move” include dc motors, RC servos, and stepper motors. This lab session will look at how you can interface a dc motor to a PIC microcontroller.

Required Theory

DC motors are simple two-lead, electrically controlled devices that convert electrical power into mechanical power through the interaction of two magnetic fields. One field is usually produced by a stationary permanent magnet (on the stator), and the other field is produced by an electric current flowing in the motor coil (on the rotor). The interaction of the two fields results in a torque that tends to rotate the rotor. For this experiment, a reversible, permanent magnet, brushed DC motor is selected. The term ‘reversible’ means the rotation of the motor can be reversed by simply flipping the terminals of the DC power supply. One such motor is shown below. I got it from my old broken printer. The dc motors are found in CD players, toy cars, cassette player, printers, etc.