A typical switched-capacitor charge pump requires no inductors, is easy to design, and can double a positive voltage or convert a positive voltage to an equivalent negative voltage. However, in some applications, only a positive supply is available...
Articles and news - 3
Simple circuit converts 5V to -10 V
Analog comparator recognizes three signal relations
Several years ago we were developing a clamp-on photometer, a hand-held instrument that could be clamped onto a communications optical fiber to indicate the presence of light, its direction of travel, and the presence of combinations of low-frequency test tone modulation...
How to correctly charge the lithium-ion/lithium-polymer batteries
Electronic designers must be aware of the ideal charging method, as it increases the battery’s lifetime and enhances its performance. Nowadays Lithium-ion/Lithium-polymer are used extensively in portable electronic devices that are frequently charged...
"Brick-wall" lowpass audio filter needs no tuning
When a system's specifications call for a lowpass filter with a steep frequency-cutoff characteristic, an engineer can opt for a “brick-wall”- filter design that features a sharp transition band...
What's a "thermal jumper" do, anyway?
I’ve always been interested in simple-looking components which solve well-defined, clear, bounded problems...
Frank J. Sprague, the man behind the motors that remade the urban landscape
Navigating the burgeoning cities of the early twentieth century would have been a very different experience without the electromechanical railway and elevator systems designed by Frank Sprague...
One microcontroller pin drives two LEDs with low quiescent current
The basis for this Design Idea is a circuit that uses three resistors and a microcontroller-I/O pin to work as input high impedance or output to independently drive two LEDs...
Solar constant lighting system uses PV-pushback-effect. Part 2 - System testing
Testing was done at various sunlight intensities. For any given sunlight intensity, VPV, IPV, VM, IM, etc., are measured...
Solar constant lighting system uses PV-pushback-effect. Part 1 - System description
Solar day lamps (SDLs) are made by simply connecting an LED array to a solar photovoltaic (PV) panel. SDLs represent a highly cost-effective way of utilizing solar energy for lighting. However, SDLs suffer from drawbacks such as daytime-only lighting, light-intensity fluctuations based on sunlight intensity, and low output on cloudy or rainy days...
Bias for HF JFET
Junction field-effect transistors usually require some reverse bias voltage to be applied to a gate terminal. In HF and UHF applications, this bias is often provided using the voltage across the source resistor...
