Engineers know they’ll get a poke if they touch household ac wires. But RF current typically is not felt as electric shock because the frequency is too high to depolarize nerve membranes. However, RF current can cause both internal organ damage and surface radiation burns, so care must be taken to avoid high exposure. It’s […]
FAQ
Scope-based diagnosis of three-phase motor drives
Ordinary oscilloscopes can view basic parameters in modern motor drives, but operational insights generally require specialized power analyzers. Variable frequency drives (VFD) generate carefully controlled pulse-width modulated (PWM) waveforms to modulate the speed of industrial ac motors. Often, the motors involved are three phase. Three-phase ac induction motors (ACIMs) are widely used though they are […]
Measuring power choke inductances
The inductance of power chokes changes with current level. Conventional small-signal-measuring bridges are out of their depth here! Hubert Kreis, ed-k • Alan Lowne, Saelig Co. Inc. With the exception of air-core coils, all power inductances show a saturation behavior; their inductance drops with rising current. The core materials can lose permeability and then behave […]
With so many mandates, can successful designs still be achieved?
The overlap among best design practices, regulatory mandates, and project requirements may result in conflict and unachievable project results. Engineers are used to designing with respect to constraints and tradeoffs: after all, that’s what design is mainly about. If there were no such tradeoffs, getting a project completed and signed off would be far, far […]
Audio measurements for product development
It pays to know the fundamental parameters that quantify the performance of sound equipment. Daniel Knighten, Audio Precision Quantitative, objective audio measurements have a role to play not just during design validation and as a manufacturing quality control tool, but during all stages of product development . They even come in handy during the earliest […]
What is the controller area network (CAN) bus?
The controller area network (CAN) bus was developed to support the networking of large numbers of electronic control units (ECUs) in automobiles. CAN is implemented using unshielded twisted pair (UTP) cabling, designed for reliability in electromagnetically noisy environments. CAN has evolved significantly since it was first introduced in 1986, along with early ECUs. Today, there […]
Whatever happened to parallel interfaces?
Back in the early days of desktop personal computers, parallel interfaces were the norm rather than the exception. The parallel moniker refers to the way the data is sent; parallel ports send multiple bits of data simultaneously, as opposed to serial communication where bits pass one-at-a-time typically over a single connection. The rationale for parallel […]
EMI testing for IoT transceivers
A few oscilloscope measurements can give insight into sources of electromagnetic interference that garble the operation of wireless IoT devices. Examine a typical wireless device with an internet of things connection and you’ll likely find multiple RF receivers squeezed together in close proximity onto a circuit board. Cramped quarters characterize modern IoT electronics, so sensitive […]
What is the onboard diagnostics system, OBDII?
OBDII is the second-generation onboard diagnostic (OBD) interface. The first generation of OBD coincided with the advent of onboard computers in vehicles. Initial OBD systems were intended to provide technicians with information on the status of various vehicle systems, with an indicator light on the dash to alert drivers of a malfunction. OBDII includes more […]
What you need to know about error analysis in PCIe 6.0 Designs
The much-awaited next generation of PCIe makes it important to understand bit error-rate measurements. Hiroshi Goto, Anritsu Co. PCI Express (PCIe) 6.0 is being developed to meet the high-speed data transmission needs of emerging applications, particularly data centers supporting 5G. It features a doubling of data rates and other enhanced performance specs but at a […]