This handy tool lets you test active and passive components at frequencies up to 3 GHz. I tried an early unit, using it for radiated and conducted EMI emissions testing. After almost ten years, Picotest has launched a new version of its Harmonic Comb Injector (generator). The J2150B ($495) is one of the pieces I’ve […]
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Getting the most from your oscilloscope: part 3
Built-in math operations enable your scope to calculate and display measurement results. In part 1 of this series, we looked at the features oscilloscopes have offered for the past three-quarters of a century. In part 2, we looked at some of the unique features of modern digital scopes. In this part, we’ll take a closer […]
Get the most from your oscilloscope: part 2
Modern scopes add a variety of new measurement and math features to the vertical, horizontal, and trigger controls used over a span of decades. In part 1 of this series, we looked at the features, such as the vertical, horizontal, and trigger controls that have appeared on oscilloscopes since the mid-20th century and that remain […]
Get the most from your oscilloscope: part 1
Oscilloscope technology has evolved from electromechanical assistance for hand-plotting to the development of full-featured automated digital instruments. The oscilloscope is an invaluable instrument that provides engineers with a picture of how signals inside their circuits behave. Today, they have evolved from analog versions, where the only option for long-term storage was to take a Polaroid […]
How to choose analog-signal-chain components: part 5
Transimpedance and transconductance op amps convert currents to voltages and voltages to currents. We concluded part 4 of this series with a look at the instrumentation amplifier. Like the other op-amps and filter circuits we have so far described, the instrumentation amp is a voltage-input, voltage-output device. Sometimes, however, we may need a current-input voltage-output […]
How to choose analog-signal-chain components: part 4
Op amps find use in second-order filters and instrumentation amplifiers. In part 3 of this series, we described using the op amp to build some single-pole filters. Q: How do we build higher-order filters? A: Figure 1 shows one approach to a low-pass filter using the Sallen-Key topology. With two capacitors, it’s a second-order filter. […]
How to choose analog-signal-chain components: part 3
Use op amps, resistors, and capacitors to build high-pass, low-pass, and bandpass filters. In part 1 of this series, we looked at a noisy signal and discussed why it might be better to use an analog filter instead of a digital filter. Then, in part 2, we looked at the operational amplifier (op amp) and […]
Do you need a real time oscilloscope or a sampling oscilloscope?
Real-time oscilloscopes capture a signal in a single pass, while sampling oscilloscopes, sometimes called digital communication analyzers or equivalent-time sampling oscilloscopes, take multiple samples over several periods of a signal, allowing for a slower sampling rate and potentially higher resolution. Both are subcategories of digital storage oscilloscopes (DSOs). Real-time scopes are ideal for capturing one-shot events […]
How does a coating thickness gauge work and how are they used to value classic cars?
A coating thickness gauge, also known as a paint meter or paint thickness gauge, measures the total thickness of paint and other coatings. It determines the distance between the probe and the base material, including all layers of paint, primer, and any additional materials, such as filler. Common sensor technologies used include magnetic induction, eddy […]
What is intersymbol interference — and why should I care about it?
Real-world digital signals and their channels are characterized by complex equations that lead to improved link performance. When engineers think or talk about digital signals, there’s often the sense that these are nice rectangular pulses with right-angle squared-off corners, but that’s only in the ideal world. In the real world, signal challenges begin with how […]
