Digital potentiometers – digipots – are a widely used, versatile, flexible, and feature-laden alternative to classic mechanical potentiometers. Mechanical potentiometers are standard passive components that designers have used for decades in applications ranging from circuit trimming to volume control. However, they have their limitations: their wipers can wear out, they are susceptible to moisture ingress, […]
Why I still like electromechanical relays – and you should, too (maybe)
The solid-state relay may be the first choice, but the venerable electromagnetic relay offers attributes the SSR cannot provide and so may be the best solution. Everything is solid-state these days, right? Even that one holdover, the vacuum-tube magnetron at the heart of the home microwave oven, is seeing some early signs of competition from […]
Breadboards evolve to meet 21st-century design needs, Part 3: The present and near future
The classic wooden breadboard is obsolete, but its name refers to a vital engineering tool that has changed to meet today’s component and design realities. Wooden breadboards are obsolete as platforms for circuits using modern components, of course, and so-called solderless breadboards are also of very limited usefulness. At the same time, the way designers […]
Breadboards evolve to meet 21st-century design needs, Part 2: Recent past and present
The classic wooden breadboard is obsolete, but its name continues to refer to a vital engineering tool that has changed to meet today’s component and design realities. As leaded components such as discrete transistors and low-pin-count ICs in DIP packages came into use in the late 1960s and 1970s, breadboarding technology evolved as well. Among […]
Breadboards evolve to meet 21st-century design needs, Part 1: The “Ancient” Past
The classic wooden breadboard is obsolete, but its name continues to refer to a vital engineering tool that has changed to meet today’s component and design realities. Breadboards have a special place and multiple meanings in the engineering lexicon. So, what is a breadboard? It can be a crude try-out version of a subcircuit to […]
What is “orthogonal”? (Part 4): eye diagrams
The phrase and concept “orthogonal” is widely used in engineering, but it is also often misunderstood. Just as both the time domain and frequency domain are two legitimate ways of looking at a signal from different perspectives linked by the Fourier transform, the constellation diagram has a time-domain complement called the eye diagram or eye […]
What is “orthogonal”? (Part 3): signal constellations
The phrase and concept “orthogonal” is widely used in engineering, but it is also often misunderstood. We can look at orthogonal signals in multiple ways: in the time domain, the frequency domain, as a constellation – a presentation which is widely used in the broad discipline referred to as signal processing, and as an eye […]
What is “orthogonal”? (Part 2): signal space
The phrase and concept “orthogonal” is widely used in engineering, but it is also often misunderstood. The formal definition of orthogonal signals does not necessarily mean that they are unrelated or uncorrelated, although that is how the term is often used in casual “engineering speak.” Formally, two vectors are orthogonal if their dot product is […]
What is “orthogonal”? (Part 1): mechanical design
The phrase and concept “orthogonal” is widely used in engineering, but it is also often misunderstood. I was chatting the other day with a non-technical friend and said something like, “Oh, that won’t happen. Those two things are orthogonal.” My friend looked at me and replied with a “huh?” and he was right to do […]
Why I’m divided on “Right to Repair”
Mandating a “right to repair” seems like a good idea, but what are the details and risks? As an engineer, I like to fix things, or at least try to. That’s why I have been following the “right to repair” (RTR) movement, which is getting a lot of attention these days (just Google it and […]