Single-cell lithium-ion (Li-ion) chargers are widely used, yet many practical designs rely on highly integrated ICs that conceal their internal operation. The type of Li-ion charger outlined in this design is, somewhat surprisingly, not readily ...
This easy-to-build PWM source is a handy testing tool for hobbyists, technicians, engineers and other RC-based device developers. I work at a university where I’m charged with designing and developing all manner of circuits and systems for ...
Convert a 4-20 mA signal to 0-20 mA and deliver it to a grounded load with no additional power supply needed. Recently, EDN kindly published a design of mine for a micropower 4-20 to 0-20 mA current loop converter ( Ref. 1 ). Shortly thereafter, in ...
Version 1 A single lithium ion battery cell needs 4.2 V from a current source to insure it is fully charged. A solar panel with just enough individual cells wired in series to produce the needed voltage would be more efficient than one with more ...
The iconic LM2917 tackles frequency-to-current conversion with (very) few externals. Almost exactly 50 years ago in June 1976, to be precise National Semiconductor introduced the LM29x7 series, offering deceptively simple monolithic solutions to a ...
There are many applications when a remote switch’s on/off status needs to be monitored. Reed relay sensors, toggle control switches and security alarms contacts are just a few examples. Routing a switch directly to a computer system hundreds ...
This project presents the design and implementation of a dual-fan PWM cooling circuit, integrating a compact and efficient power supply with intelligent fan speed regulation. The circuit consists of two main parts: a 6 W isolated flyback converter ...
This simple circuit can protect a sensitive electronic circuit from an accidental connection of a battery with a reversed polarity. The N-channel FET connects the electronic device to the battery only when the polarity is correct. The circuit shown ...
This Design Idea describes a versatile test circuit for zener diodes after yet another misread zener diode had infiltrated the ranks of 1N4148 diodes assembled on a pc board. As a bonus, the circuit can serve as a moderate-voltage, power-limited ...
This circuit design for power supply on/off sequencing uses Schmidt triggers for triple-positive-rail timing purposes. Recent design ideas have explored the utility of timed power supply ON/OFF sequencing and provided circuit designs to implement ...