Teardown: Inside Ikea’s smart LED bulb
As smart LED bulbs go, this one is pretty simple. It doesn’t incorporate any sort of smartphone app and can’t be controlled over the Internet, like some other smart bulbs we’ve seen.
What is a charge pump and why is it useful? (Part 1)
It’s a very common challenge in circuits to need to convert an available DC source to a lower or higher voltage. For the high-to-low conversion, one option to use a low dropout regulator (LDO), but how to easily transform a lower voltage into a higher one?
What are amplifier classes and their power efficiencies?
Amplifiers which must produce significant output power face challenges of performance and efficiency. The industry has some long-established designations for classes of amplifiers as well as some relatively new classes.
Better high-frequency power design through EM simulation
MOSFETs built-in silicon and the latest WBG transistors are both FETs. As such, the turn-on and turn-off behavior is largely a function the device’s composite gate charge. Until the gate-drain “miller capacitance” of the FET is charged, the device remains in a high on-resistance state.
Secrets of measuring currents above 50 amps
Traditionally, the typical way to measure current is by putting a sense resistor in series with the current-carrying conductor. An op amp may then measure the voltage drop across the resistor, and the current is calculated from Ohm’s law. The nominal resistance of the sense resistor is selected to supply a sufficiently large voltage while also minimizing the power dissipation (P = I2R).
How we devised a wirelessly powered television set
There are two widely used forms of magnetic field-based wireless power transfer techniques: inductive and highly resonant. Each has advantages and disadvantages.
Power modules lessen the load on internal combustion engines
The automotive industry is keen to ensure that the replacement electrical systems are as efficient as possible. Another concern is how proliferating electrically-driven systems may grow the size and weight of vehicle wiring harnesses. Car makers must prevent harnesses from becoming excessively large and heavy.
Why do we need all this LED driver stuff, anyway?
This is a good opportunity to review the basics of why it is inadvisable to power an LED with just a bridge rectifier/transformer/resistor and why makes of LED bulbs are forced to go to some trouble in devising current sources comprised of a bit more than these three components.
Solar cells and power, Part 2 – power extraction
As the amount of impinging sunlight changes, the load characteristic that results in the largest amount of power transfer efficiency changes. Therefore, the efficiency of the system is optimized when the load characteristic changes to keep the power transfer at the highest efficiency.
Tougher stress tests for automotive MOSFETs
To promote reliability, standards such as AEC-Q101 have been developed. But in the automotive world technology moves quickly, and any failure is unacceptable. So simply meeting these qualification standards is not enough.