A graduate student worked out the principles of using a planet’s mass to accelerate and adjust the voyage of spacecraft traversing our solar system; without it, the voyages of interplanetary probes would be impractically long. Part 1 of this FAQ scoped out the basic problem of completing interplanetary missions within a manageable time, and how […]
Gravity-assist “Slingshot,” Part 1: Background and principle
A graduate student worked out the principles of using a planet’s mass to accelerate and adjust the voyage of spacecraft traversing our solar system; without it, the voyages of interplanetary probes would be impractically long. If you follow the news about the various interplanetary probes launched by NASA, the European Space Agency (ESA) and others […]
Power management ICs, part 2: PMIC implementations
The power management IC (PMIC) is often a vital part of the lower-voltage DC subsystem, as circuits have multiple power rails with tight individual specifications as well as mandated relationships among them. Part 1 of this FAQ discussed the need for, PMICs and their general characteristics. Part 2 now looks at specific ICs which implement […]
Wheatstone bridge, Part 2: Additional considerations
Part 1 of this FAQ explained the basic principle of the Wheatstone bridge. This part will take the bridge configuration into modern applications and go beyond basic resistance measurements. Q: All this measurement via changing resistance or by measuring current seems very slow or static; how does it fit into today’s electronics? A: Frist, many […]
Power Management ICs, part 1: PMIC functions
The power management IC (PMIC) is often a vital part of the lower-voltage DC subsystem, as circuits have multiple power rails with tight individual specifications as well as mandated relationships among them. It’s one thing to develop needed low-voltage DC rails via DC/DC converters or regulators, but there’s also a need to manage these power […]
Wheatstone bridge, Part 1: Principles and basic applications
Although the electronics industry is relentlessly driven by advances in materials, components, and architectures, the “new” obviously also builds on the “old” and often still uses it, albeit in new guises. There’s still a viable place and need for old devices such as the transformer, solenoid, relay, and Wheatstone bridge. This FAQ will look at […]
Blood oxygen meters, Part 2: IC implementations
It is now trivial and non-invasive to measure blood-oxygen saturation SpO2, thanks to LEDs, algorithms, and ICs for pulse oximetry — it’s a very long way from having to draw blood and send it out for assessment. Part 1 of this FAQ discussed the principle of the non-invasive, light-based pulse-oximetry systems for reading blood-oxygen saturation […]
Blood oxygen meters, Part 1: Background and principles
It is now trivial and non-invasive to measure blood-oxygen saturation SpO2, thanks to LEDs, algorithms, and ICs for pulse oximetry — and it’s a very long way from having to draw blood and send it out for assessment. Just a few decades ago, determining the vital medical parameter known as blood oxygen level — formally […]
Quartz crystals and oscillators, Part 2: Advanced crystals
Part 1 of this FAQ established the context for the quartz crystal as the core of an oscillator whether used as a system clock or as a frequency-setting element in a tuning circuit. This part looks at the achievable performance, the factors that affect it, and what can be done for highest performance. Q: What […]
Power-supply overvoltage protection, Part 2: Clamps
Part 1 of this FAQ discussed the context of overvoltage protection and crowbars which provide OVP. This part will look at clamps for OVP use. Q: What does the clamp do? A: A clamp conducts just-enough current to maintain the voltage across it at a safe, desired value when the transient is above the clamp’s […]