Circuits & Schematics - 5

We’ve seen lots of interesting conversations and Design Idea (DI) collaboration devising circuits for power switching using inexpensive (and cute!) momentary-contact SPST pushbuttons. A recent and interesting extension of this theme by ...

Implementing a simple digital-to-analog converter (DAC) by cascading a single pulse width modulator (PWM) and an analog low-pass filter is nothing new. Nor is applying to a filter the sum of the outputs of a most significant 2 N -count PWM and a ...

“Two halves make a whole” is a very old and often true maxim. For example, it’s almost always true when said about AC phase angle power control. You rarely want significant alternating half-cycle asymmetry due to the (usually ...

Check out this link for On Semiconductor’s datasheet for a line of “Zero-Cross Optocoupled Triac Drivers.” The ability to zero-cross when turning on AC line voltage to some loads may be advantageous. The following sketch in Figure ...

A simple circuit can improve the dynamic performance of a phototransistor for use in low- to medium-speed applications as fast as 100 kbps, such as optical isolation of an RS-232C serial line (Figure 1). In low-cost applications that require high ...

Lively discussions have sprung up here in editor Aalyia Shaukat’s Design Ideas regarding the limitations and quirks of, and design tricks for, the current control topologies shown in Figure 1. Figure 1. How to control amps of I OUT with mA of ...

Meters that indicate analog levels via a moving-pointer meter, a numeric display, or a column of LEDs typically occupy considerable panel area and require more than a casual glance to read. An indicator lamp or LED takes little space but indicates ...

There have been numerous circuits published in EDN as design ideas (DI) for the past few months, centering around the “Flip ON Flop OFF” ( Ref. 1 ) circuit originally published by Stephen Woodward. These are all designed for DC voltages ...

It’s just a fact, I’m curiously fond of topologies that combine PWM switching and filtering circuitry with power handling devices like adjustable voltage regulator chips. This scheme makes power-capable DACs with double-digit wattage ...

There are multiple means of generating analog sawtooth waveforms. Here’s a method that employs a single supply voltage rail and is not finnicky about passive component values. Figure 1 shows a pair of circuits that use a single 3.3-V supply ...