Articles - 9

Permanent magnet DC (PMDC) motors offer smaller solution size and increased efficiency in applications such as portable vacuums and cordless electric power tools. When designing an isolated power supply for PMDC motors, there are several ...

The popular and multiply sourced TL431 three-terminal shunt regulator offers designers considerable versatility in its applications. Figure 1a illustrates the TL431’s internal circuitry, which comprises a precision voltage reference, an ...

The most common method for interfacing multiple switches multiplexing allows for the connection of (N/2) 2 switches with N microcontroller I/O lines. The method described below, which has its roots in an LED interface technique commonly known as ...

Many electronics circuits begin operation at voltages below 1.25 V. But popular adjustable regulators such as the LM317 , LM350 , and LM338 can provide output voltages only above 1.25 V, and the L200 minimum is higher at 2.85 V. Fixed-output ...

By adding just two MCU I/O pins, a standard LED can also perform as a light-detecting photodiode. Sometimes people forget that light-emitting diodes can also detect light quite well. They're usable in a wide range of applications as ...

How do you deliver constant power when the load impedance isn't constant? That problem arises, for example, in trying to maintain a warm LCD display on an outdoor gas pump in cold climates. As the heating element changes temperature, its ...

Audio amplifiers for high-power portable speakers such as trolley speakers usually operate with lithium-ion batteries, and these batteries can vary from a single cell to a few cells in series. Designers generally use boost converters to produce the ...

Since its invention over a half-century ago by Hanz Camenzind at Signetics, the familiar 555 analog timer (in league with its updated pin-compatible CMOS descendants) has become an iconic design element incorporated into useful standardized ...

A power supply that I was examining used an opto-coupler in its feedback path for control of its output voltage. This is a commonplace and well established design approach, but the feedback loop’s unconditional loop stability was not ...

A switched-mode power supply (SMPS) employing peak current-mode control (PCMC) requires a ramp signal to slope-compensate the inner (current) control loop. Slope compensation stabilizes the current loop, which would otherwise exhibit subharmonic ...