Negative Feedback in Electronics

Lead Image Novacek

A Look at the Opposite Side Besides closed-loop control systems, negative feedback is found in many electronic circuits—especially in amplifiers. And just like positive feedback, negative feedback can significantly change or modify a circuit’s performance. By George Novacek Following last month’s … Continue reading


Logger Device Tracks Amp Hours (Part 2)

Lead ImageWachsmann

Alternative Energy Sources In this follow on to Part 1 of his story, Bill describes putting to use the amp-hour logger that he built using a microcontroller and a clamp-on ammeter. This time he discusses modifying the amp-hour software so … Continue reading


Analog ICs Meet Industrial System Needs

Jeff Lead Image Analog Inustrial

Connectivity, Control and IIoT Whether it’s connecting with analog sensors or driving actuators, analog ICs play many critical roles in industrial applications. Networked systems add new wrinkles to the industrial analog landscape. By Jeff Child While analog ICs are important … Continue reading


Antenna Measurement Made Easy

For web Lacoste Lead Image

Covering the Basics If you’re doing any kind of wireless communications application, that probably means including an antenna in your design. The science of antennas is complex. But here Robert shows how the task of measuring an antenna’s performance is … Continue reading


FREE Sample Issue – Oct. 2017


  We’ve made the October 2017 issue of Circuit Cellar available as a sample issue. In it, you’ll find a rich variety of the kinds of articles and information that exemplify a typical issue of the current magazine. Don’t miss … Continue reading


Logger Device Tracks Amp Hours (Part 1)

For this project, I used an NXP-Freescale FRDM-KL25Z microcontroller board.

Measuring Home Electricity Setting out to monitor and log electricity usage in his house, Bill built an amp-hour logger using a microcontroller and a clamp-on ammeter. He gets into the software development details exploring solutions like mbed and Microsoft Visual … Continue reading


Gas Monitoring and Sensing (Part 1)

Table Untitled

Fun with Fragrant Analysis Gas sensing technology has come long way since the days of canaries in coal mines. This month columnist Jeff covers the background issues surrounding gas monitoring and sensing. Then he describes how he uses sensors, A/D … Continue reading


Commercial Drone Design Solutions Take Flight

The Intel Aero Ready to Fly Drone is a pre-assembled quadcopter built for professional drone application developers. The platform features a board running an Intel 2.56 GHz quad-core Intel Atom x7-Z8750 processor.

Chips, Boards and Platforms The control, camera and communications electronics inside today’s commercial drones have to pack in an ambitious amount of functionality while keeping size, weight and power as low as possible. By Jeff Child, Editor-in-Chief There aren’t many … Continue reading


Emulating Legacy Interfaces

Photo 1 - The PC/104 specifications relate to small modules, which can be stacked one above the other.

Do It with Microcontrollers There’s a number of important legacy interface technologies—like ISA and PCI—that are no longer supported by the mainstream computing industry. In his article Wolfgang examines ways to use inexpensive microcontrollers to emulate the bus signals of … Continue reading


Numeric Precision vs. DDS Calculations

A knockoff Arduino Nano controls a generic AD9850 direct digital synthesizer circuit, both plugged into standard 0.1 inch headers, with hand-wiring connections below the proto board. The SMA connector provides a mechanically rugged output from the board; the DDS frequencies don’t require its RF properties.

Using the full frequency resolution of a direct digital synthesizer chip outstrips the capabilities of floating point numbers. Ed takes a look at what’s needed for high-resolution frequency calibration and measurements. By Ed Nisley As you saw in my July … Continue reading


Getting Started with PSoC MCUs (Part 3)

For web Figure 1

Data Conversion, Capacitive Sensing and More In the previous parts of this series, Nishant laid the groundwork for getting up and running with the PSoC. Here he tackles the chip’s more complex features like Data Conversion and CapSense. By Nishant … Continue reading


Time-Oriented Task Manager

A graphic representation of a time-oriented task manager and its tasks

…for 8-bit PIC Microcontrollers For many new embedded applications, an 8-bit MCU is just right. Pedro shows how to build a time-oriented task manager using Microchip’s PIC 16F628A 8-bit microcontroller. By Pedro Bertoleti Microcontrollers are everywhere. From a simple remote … Continue reading


Breaking a Password with Power Analysis Attacks

Breaking a Password with Power Analysis Attacks

In his previous column, Colin showed how timing attacks could be used to break a password check. This article brings out a more advanced type of attack called a power analysis attack, which exploits small leaks about internal states of … Continue reading


Digital Guitar Amplifier/Effects Processor

This is a block diagram of the audio signal flow through the guitar amplifier.

Part 2: Design and Construction In the first part of this series, Brian introduced the Teensy 3.2 MCU module. Now he presents a digital guitar amplifier/effects unit that he built around two Teensy modules. By Brian Millier In the first … Continue reading


Find and Eliminate Ground Loops

FIGURE 4: Ground isolator for three-prong powered appliances

Everything had been fine with my home entertainment center—comprising a TV, surround-sound amplifier, an AM/FM tuner, a ROKU, and a CD/DVD/BlueRay player—until I connected my desktop PC, which stores many of my music and video files on one of its … Continue reading