Spare a moment’s pity for the process engineer, whose job it is to keep industrial automation running no matter what. These poor souls seem to be forever on call, fielding panicked requests to come to ...

Lighting a string of LEDs at a constant brightness requires driving it with a regulated current. A boost converter is commonly used to step up the voltage to a level high enough to bias the LEDs on ...

A bi-directional current source for a grounded load will always have some complication in its construction. The improved Howland Current Pump as shown in Figure 1 is the most frequent choice for this ...

The current-mode or peak-current-regulating switching converter is a familiar, almost dominant, power supply circuit consisting of few parts and is usually designed with “cookbook” procedures from PWM ...

LED-driver circuits can be dimmed by applying a variable duty cycle (pulse-width modulation, or PWM) to the LED. PWM exploits LED behavior: At higher current levels, the LED’s light output is higher ...

Fig 1. The buck converter schematic shows the voltage feedback loop and the fast peak CMC loop. The current waveform as seen by the shunt is the dominant signal at the ramp of the PWM comparator. Fig ...

In a previous article, I discussed LEDs in general and their properties. In this write-up, I want to give some examples of driving LEDs and comparing a few of the most commonly used methods. There is ...