Ordinary conductors such as copper and silver exhibit less resistance as the temperature drops. But even near absolute zero they still have some resistance. With true superconductivity, the resistance of certain materials drops to precisely zero when they hit a certain critical cold temperature. This type of superconductivity is a quantum mechanical process that involves […]
Basic instrumentation for the electronics workbench
Engineers and technicians doing design, development, and testing have a wide range of instrumentation available for use on the test bench. So it might be useful to consider which instruments are considered the “basics” for the general case. Here are a few nominations along with the device properties that are generally considered “must-haves.” The unassuming […]
Difference between linear amplitude and decibel amplitude
In the time domain, amplitude, the dependent variable, is shown in volts relative to the Y-axis. In an oscilloscope display, for example, we may see branch circuit voltage as 325 V peak-to-peak, but the meaningful figure is 115 to 120 V, depending on your distance from the transformer, wire size and loading. One hundred and […]
Wiring for instrumentation labs
Most concerns about test instrumentation center on making accurate measurements. Engineers tend to take the underlying electrical infrastructure for granted. But it can be reassuring to know the lab electronics plug into an electrical system that is up to the task. Above all, any electrical installation must comply with the current electrical code, and an […]
The difference between a pulse generator, a signal generator, an AFG, and an AWG
There are a variety of instruments available to generate electronic signals these days. They go by different names and provide different kinds of outputs. Differences between the various kinds of instrumentation aren’t always obvious, so here is a short primer. Signal generators make available at their outputs sinusoidal waveforms with a settable frequency or amplitude. […]
Setting up a serial or parallel bus in the Tektronix MDO3000 Series oscilloscope
The buttons that access digital functions in the Tektronix MDO3000 Series oscilloscope are grouped together near the bottom of the front panel, just above the analog ports and the Analog Channel One input. Nearby is an insulated cover over the digital input ports and the digital D15-0 button. You may wonder how it is possible […]
Working with the Tektronix AFG31000 Series arbitrary function generator
The Tektronix AFG31000 Series Function Generator can be used in conjunction with an oscilloscope to display the generated signals in one or two analog channels on a large LCD. Alternately, the AFG has smaller waveform displays with reduced resolution, nonetheless adequate for demonstrating the functionality of this powerful instrument. When initially powered up, the AFG […]
The difference between noise and jitter
Noise and jitter in electronics are closely related phenomena. Both are unwanted electrical energy that we mitigate where possible and otherwise work around. Weak signals are obscured by noise. No amount of filtering can reduce noise that is caused by fluctuations intrinsic to the signal being measured, but this noise can be partially eliminated by […]
Testing and diagnosing ac motor controllers
The National Electrical Code in Article 430 specifies that all electrical motors are to have suitable controllers. When the motor runs at a constant speed, the controller can be relatively simple. It is often not much more than an on/off switch, though there are more sophisticated versions that include provisions for handling different types of […]
Poor earth ground on satellite dishes can put you in orbit
In a satellite dish, as sometimes used to receive internet signals transmitted via satellite, the signal transmitted by a satellite transponder is reflected by and propagated through a circular or rectangular tube, which is part of the feedhorn. This tube, like all waveguides, has dimensions based on the wavelength of the signal. Its purpose is […]