Earth’s magnetic field is far stronger than that of Venus or Mars, and this single fact explains why life on earth is abundant while its nearest neighboring planets do not at present support life. Earth’s magnetic field extends from its outer core (where swirling molten iron produces a dynamo effect) up through the magnetosphere, extending […]
FAQ
How to use oscilloscopes with integrated test instrumentation
Many manufacturers have in recent years have introduced oscilloscopes with integrated test instrumentation. This means that the smaller and lighter oscilloscope enclosure actually houses about five additional test instruments. An example is the Tektronix MDO3000 Series which includes a digital voltmeter, arbitrary function generator, spectrum analyzer, logic analyzer, and protocol analyzer. All this integrated test […]
The difference between arbitrary function generators and arbitrary waveform generators
Signal generators are subdivided into categories that include arbitrary function generators (AFGs) and arbitrary waveform generators (AWGs). The word arbitrary denotes a user’s ability to create waveforms beyond the permanent contents of the instrument’s internal memory. Besides AFGs and AWGs, there are RF and microwave signal generators, pitch generators, digital pattern generators, and more. Typically, […]
Measuring pulse-width modulation outputs in industrial equipment
Pulse-width modulation (PWM) is a widely used means of controlling power to large induction motors by means of variable-frequency drives (VFDs). The VFD is capable of varying the speed and torque of an otherwise single-speed ac motor, typically a three-phase 480-V induction motor. Typically housed in a floor-to-ceiling steel enclosure, the VFD modifies the power […]
Measuring polarization
Any treatment of wave polarization must begin with a discussion of the differences between transverse and longitudinal waves. That is because polarization either as a process or a state applies only to transverse waves, not to longitudinal waves. Longitudinal waves are those in which the oscillations are in the direction of propagation. Examples of longitudinal […]
Understanding sampling modes in digital oscilloscopes
In a digital oscilloscope, the analog signal is at the input, after attenuation/amplification and preliminary filtering such as for ac coupling, goes to an analog-to-digital converter (ADC). Each channel has a separate ADC, each with an external clock. Analog-to-digital conversion takes place by means of sampling. The samples are taken at specific rates and the […]
Logic analyzer basics: The difference between a scope and a logic analyzer
The logic analyzer is an advanced instrument that displays the content of numerous digital data streams simultaneously and in various formats. It is continuously evolving. Manufacturers are offering new and ever more advanced features that facilitate with great precision design, debugging and repair of digital systems. While the oscilloscope remains relevant in the digital domain, […]
Basics of testing CMOS
The term complementary metal-oxide semiconductor (CMOS) has become a partial misnomer because the dielectric layer that separates gate and source is now rarely a metal oxide. The name persists despite this change. CMOS refers to pairs of MOSFETs in symmetrical configurations, which in turn are slightly modified FETs. CMOS circuits have become by far the […]
Testing and debugging the I2C digital data bus
“Bus” is an old term derived from conductive elements that are part of an electrical distribution system, generally referring to short specialized conductors separate from the overhead or underground cable. Typically, the old-style buses consist of bare copper bars, often having a rectangular cross-section, firmly mounted in an enclosure and capable of carrying current at […]
Measuring clock and oscillator frequency
A clock may refer to an oscillator that has been designed to provide a timing signal to facilitate operation of one or more synchronous processors. In contrast, asynchronous operation does not require a clock because each step initiates upon completion of a prior step. It is potentially faster than synchronous operation because there is not […]
