LEDs 'making light pollution worse'
03.06.2018 · Articles
The transition from sodium to LED exterior lighting over recent years appears to have made global light pollution worse not better, scientists have reported. A team of researchers who studied NASA images say that in the last four years the illuminated area of the earth grew by 2 per cent...
Teardown: Smart switch provides Bluetooth power control
02.28.2018 · Articles
I've tested (and tore down) several network-controllable power switches of late; Belkin's WeMo and, more recently, TP-Link's HS100, both Wi-Fi based. Then there's GE's Avi-on line. Unlike the others I just mentioned, it's Bluetooth-based, and with a twist...
Make sure your optocoupler is properly biased
02.21.2018 · Articles
In isolated power supplies, optocouplers pass the feedback signal across the isolation boundary. Optocouplers contain both a light-emitting diode and a photo detector. Current flowing through the LED results in a proportional current flowing in the photo detector...
Vintage electrical measuring instruments from the 1950s
02.06.2018 · Articles
When EDN published its first issue in 1956, electrical measuring instruments looked a little different than they do today. Howard Skolnik, a former colleague and key analog mentor from my Burr-Brown days, has always had a passion for significant products made by pioneering electrical instrument companies and has accumulated a large collection over the years that includes Burr-Brown, General Radio, Leeds, and Northrup and Weston...
Inside an isolated RS-485 transceiver
01.24.2018 · Articles
Isolation is a means of preventing current flow between two communicating points, while allowing data and power signal transmission between them. Isolation prevents high voltages from damaging sensitive electronic components or harming humans. It also eliminates ground loops in communication links with large ground potential differences to maintain signal integrity...
Simple Transient-Response Measurement Determines Power-Supply Bandwidth
01.11.2018 · Articles
It’s normal to assume that there’s an easy way to relate the bandwidth of a power-supply control loop to its transient response – no good reference exists that defines this in simple terms. It seems like a straightforward problem, which should have a simple solution. The higher the bandwidth, the faster the loop responds, and with less voltage deviation...
Synthesized Inductor Delivers Maximum Power Transfer
12.28.2017 · Articles
To transfer maximum power from a circuit to a load, the load’s resistance, RL, must match the source resistance, RO. In the case of a complex load, ZL, and a resistive source, this transfer can require the use of a bulky inductor. This idea shows how to replace the physical inductor with a smaller synthesized inductor...
10 Best Raspberry Pi and Pi 2 Alternatives. Part 2
There are actually two versions of the MinnowBoard MAX available; a $140 version and a $100 version. The extra $40 gets you 2 GB of RAM instead of 1 GB, but both versions include a 1.33 GHz dual-core processor...