Measuring the position of a rotating shaft, speed or direction of motion typically requires a rotary encoder. The two main types of encoding techniques are: absolute and incremental encoders. The absolute encoding technique provides a specific and unique position value for every point of rotation when it is switched on. Absolute encoding is commonly achieved […]
FAQ
What is the difference between current feedback and voltage feedback op amps?
Current feedback (CFB) operational amplifiers (op amps) and voltage feedback (VFB) op amps have almost as many similarities as differences. CFBs and VFBs both have inverting and non-inverting inputs, a signal output, inputs for positive and negative voltage supplies and use feedback and gain resistors to stabilize circuit operation and set circuit gain. That can […]
Measuring a sense-resistor’s voltage drop, Part 2: Isolation
Measuring the voltage drop across a current-sense resistor can be a trivial issue or a challenging one depending on the rail voltage and other factors. The problem with low-side sensing is that it “ungrounds” the load, and the alternative is high-side sensing. This part looks at the use of isolation to deal with CMV […]
What are switched capacitor filters, amplifiers and integrators?
Switched capacitors (SCs) are highly-versatile circuit elements that can be used to provide various functions, ranging from micro-scale implementations embedded in integrated circuits (ICs) or designed into wearables and other small devices, to a variety of power conversion applications, up to grid-scale systems. This FAQ series will explore the versatility of switched-capacitors. Following this initial […]
What is pseudorandomness and why is it useful?
Pseudorandomness is a measurement of the degree to which a sequence of numbers, though appearing to be random, is produced by a deterministic and repeatable process. True randomness is a stochastic quality of a sequence which has a probability distribution or pattern that may be analyzed statistically but may not be predicted precisely. Pseudorandom sequences […]
Measuring a sense-resistor’s voltage drop, Part 1: Sensing issues
Measuring the voltage drop across a current-sense resistor can be a trivial issue or a challenging one depending on the rail voltage and other factors. In previous articles, we looked at an apparently simple issue of sizing the resistor used for this common technique for current sensing (EE World Content References 1 and 2). This […]
Antennas and antenna measurements
Most antenna designs operate via the resonance principle, which is based on the fact that electrons moving through a conductor reflect back toward the power source when encountering a discontinuity. When current, caused by a radio signal’s induced voltage, reaches the end of the antenna element, it is reflected, travels in the reverse direction, and […]
How to shrink size and boost performance with low inductance electrolytic capacitors
By Suzana Jankuloska, Aluminum Electrolytic Product Manager at KEMET Corp Electrolytic capacitors optimized for low internal inductance can help reduce the cost of industrial power-conversion applications while increasing efficiency, performance, and reliability. As the automation of manufacturing and assembly processes continues to become more widespread, driven by emerging trends such as Industry 4.0 and the […]
Under the hood of PV inverters
One of the advantages of photovoltaic (PV) energy is that it is inherently modular. Unlike many other energy sources, it allows the implementation of small-, medium- and large-scale generation systems, ranging from portable and rooftop systems to large multi-megawatt PV farms. System requirements, performance specifications, regulations, and even the economics behind the different system sizes, […]
PV module specifications and performance parameters
The nameplate ratings on photovoltaic (PV) panels and modules summarize safety, performance, and durability specifications. Safety standards include UL1730, UL/IEC61730, and UL7103, a recent standard for building integrated photovoltaics (BIPV). Safety standards ensure that PV modules demonstrate non-hazardous failure modes. Performance standards include IEC 61215, which specifies requirements for the design qualification and type approval […]