Induction heating is widely used in industry and even consumer appliances as a contact-free heating technique with many distinct advantages. The understanding of induction heating begins with basic electromagnetic principles and that very ancient electrical component still in very wide use: the transformer. However, an induction-heating transformer does not resemble a standard AC-line power transformer, […]
Basics of induction heating, Part 1: Introduction
Induction heating is widely used in industry and even consumer appliances as a contact-free heating technique with many distinct advantages. A very common design challenge for many engineers is to manage and dissipate excess heat produced within or impinging on a system so the temperature of that system or some of its components does not […]
Sometimes, your long-standing beliefs aren’t quite right
To resolve design issues, it may be necessary to question the root source of some fundamental accepted practices and assumptions. From an early age, we all are taught some basic truisms. For example, we learn that the “normal” typical oral human-body temperature is 98.6⁰F (conveniently, that’s 37.0⁰C). Many decisions, such as concluding that someone has […]
Getting one wire to do more, Part 4 – headphone wire as antenna
Using one wire in two very different roles is widely done, requiring some simple circuity and basic components. Using a headphone wire as an FM antenna The earliest portable AM/FM portable radios used two antennas: an internal long wire wound on a ferrite core for the lower-frequency AM band (550-1600 kHz), and a “whip” antenna […]
Getting one wire to do more, Part 3 – Powering the antenna LNA
Using one wire in two very different roles is widely done, requiring some simple circuity and basic components. Providing DC power to an antenna amplifier via an RF coaxial cable In most applications where the antenna is located at a distance from the radio receiver front end, it is desirable or necessary to add a […]
Getting one wire to do more, Part 2 – Phantom power for the microphone
Using one wire in two very different roles is widely done, requiring some simple circuity and basic components. A classic engineering objective is to figure out a way to get one set of wires to provide a second function at little cost. This second part in the series looks at phantom power in more detail. […]
Simple double-duty: How to get one wire to do more, Part 1: The rationale
Using one wire in two very different roles is widely done, requiring some simple circuity and basic components. It makes a lot of sense to use an individual single copper cable and its connection between two points to do more than it initially intended, especially if that additional function is aligned with the primary function […]
Unipolar vs. Bipolar drive for stepper motors, Part 2: Tradeoffs
Stepper motors can be configured for unipolar or bipolar drive; each approach has different performance attributes and tradeoffs. The previous part of this article presented the basics of different coil windings and connections for unipolar and bipolar stepper-motor configurations. As in most engineering situations, the next questions are: what is the impact of these differences? […]
Unipolar vs. Bipolar drive for stepper motors, Part 3: Drive ICs
Stepper motors can be configured for unipolar or bipolar drive; each approach has different performance attributes and tradeoffs. Despite their usefulness and suitability of stepper motors for precision positioning, especially in back-and-forth motion applications, one of the factors which delayed their widespread adoption was the challenge of providing the needed driver management. However, the introduction […]
Unipolar vs. Bipolar drive for stepper motors, Part 1: principles
Stepper motors can be configured for unipolar or bipolar drive; each approach has different performance attributes and tradeoffs. Stepper motors are widely used, and, as with so many basic components, they are simple in some ways but also have multiple configurations and operating subtleties. For steppers (the “motor” part of the two-word term is often […]