Kirchhoff’s voltage law gives us three equations with three unknowns to solve for loop currents in an unbalanced Wheatstone bridge.
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Making sense of test circuits with Kirchhoff’s laws: part 2
In part 1 of this series, we looked at ways to simplify resistor networks by identifying series and parallel combinations of resistors. We closed with a look at a version of the Wheatstone bridge, such as the one in Figure 1. Although it has only five resistors, not one of them is in series or […]
Noise generator substitutes for tracking generator
When your spectrum analyzer lacks a tracking generator, you can use a low-cost noise generator to characterize RF components. Here’s how. Low-cost spectrum analyzers often lack tracking generators, preventing you from having a signal source that tracks the analyzer’s frequency sweep. Not having a tracking generator can make some measurements difficult. You can, however, use […]
Making sense of test circuits with Kirchhoff’s laws: part 1
You can avoid solving simultaneous equations in multiple unknowns by identifying series and parallel combinations of resistors. When you buy test instruments, you hope they’ll have the flexibility to provide the necessary stimulus to the device under test (DUT) and acquire and process the response. Occasionally, however, you’ll need to design an external network to […]
Tryout: two low-cost USB inline meters and a load
Despite their limited use for testing wall chargers and power banks, USB inline testers let you compare power sources. In three videos, we take you through their features, and we also try an inline USB electronic load. When testing a USB charger or power bank, you can connect a phone or other device and see […]
Contending with Windows 10’s retirement: part 4
A continuous process of technical architecture modernization can help you prepare for any operating system’s inevitable demise. With the retirement of Windows 10, as described in part 1 of this series, users of the operating system to control test and measurement systems have a choice to make. In part 2, we looked at what steps […]
Make the most of oscilloscope triggering: part 1
Learning the basics of oscilloscope triggers can help you leverage advanced features. In an earlier series, we discussed how the oscilloscope has evolved over the past three-quarters of a century. We noted that the basic horizontal and vertical controls remain functionally similar, but today’s digital oscilloscopes offer many features, including waveform math functions, that go […]
Locate ESD sources using an oscilloscope and two antennas
The key to identifying the location of an ESD source is by measuring the time of arrival between the two antennas. ESD discharges are tough to locate because they don’t occur periodically. Rather, they occur intermittently. I earlier wrote an application note on how to use an oscilloscope to trace the path of ESD current […]
Contending with Windows 10’s retirement: part 3
You can take several steps to ensure success when you upgrade to Windows 11. In part 1 of this series, we looked at the use of Windows to control test and measurement systems, and we considered the dilemma posed by the retirement of Windows 10 on October 14. In part 2, we looked at steps […]
What’s the difference between live zero and dead zero?
Live zero is a non-zero signal value, like 4mA in a 4-20 mA loop, that represents the lowest measurement confirming the signal is live, and the system is operational. Dead zero occurs when a zero-based signal like 0 mA or 0 V indicates the lowest measurement, making it impossible to distinguish between a true zero […]
