During the first decade of this century, advances in several disparate technologies set the stage for a substantial rise in autonomous and semi-autonomous remote intelligent-node deployments that continues to this day. This trend arose in applications as different as hydrological surveying, transportation tracking and management, and machine health. It also has kicked off a flurry […]
Flashovers and clearance in electronic equipment
Electronic circuits accomplish so much with single-digit supply voltages that it’s easy to lose track of the precautions that higher-voltage circuits demand. But getting to those single-digit supplies often requires power-train sections operating at hazardous potentials. Although human safety is a key concern, it isn’t the only one. If sufficient clearances aren’t maintained between conductive […]
Choosing an integration level for power supply functions
Since the first application of the wheel, an element of all practical engineering projects has been the make-or-buy decision. The issue is fractal, arising at every level of the design hierarchy: For any given function, at some level of abstraction, you’ll choose to switch between make and buy. But the decision doesn’t hinge on a […]
Ode to reliable USB connectors
Because our work depends so much on the technologies we utilize, one of our year-end reviews covers a post-mortem summary of all failures related to our equipment use. The summary includes system failures, which are thankfully rare, and also encompasses use-model failures such as our discovery that the RF data-link receivers we use on location […]
Less famous attributes of Schottky diodes
Schottky diodes are useful in some power-converter topologies, especially for shunting the body diode in a half-bridge’s low-side MOSFET. In this position, the Schottky diode prevents the body diode from turning on, particularly when driving inductive loads common in power converters, because it’s forward voltage drop is smaller than that of the body diode’s PN […]
Remember the MOSFET body diode
Unlike virtually every other active device, the power MOSFET is unusual in that its schematic symbol includes a parasitic device – the body diode. The body diode is intrinsic to the device’s structure. It remains despite a number of fundamental changes in power MOSFET structure and device designs including the two most common types today […]
Basics of understanding power-factor and power-factor correction
In qualitative terms, power factor is a measure of the congruency of voltage and current ac waveforms imposed by a load on the power mains. Ignoring the relative…
FAQ: What are the benefits of 48-V distribution?
Mains-connected computational resources have been powered primarily by 12-V distribution feeds for decades. The 12-V distribution potential has been a convenient choice because it lets designers route power…
What engineering school doesn’t teach about ceramic capacitors
Ceramics comprise the most widely used non-polarized dielectrics. The reason is they offer attractive combinations of volumetric efficiency, manufacturability, and cost. Some applications — such as high-frequency RF…
FAQ: What engineering school doesn’t teach about electrolytic capacitors
by Joshua Israelsohn, Director, JAS Technical Media Why are electrolytic capacitors such a pain? Several reasons come to mind, but the A-#1, everybody’s-favorite is (or should be): reliability….