Circuits & Schematics - Supply

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 ...

Are you tired of dealing with the damaging effects of inrush currents on your industrial devices? Look no further than an AC inrush current limiter (soft starter). Inrush current, also known as surge current, is the large amount of current that ...

Simple analog circuits manage multi-PSU powerup and shutdown sequences In projects containing digital and/or analog circuits, multiple power supplies are used, generally 5 V DC for digital circuits and 15 V DC for analog circuits. Some projects ...

This circuit uses a flat piezoelectric wafer, glued inside a plastic box, as a finger tap sensor. With each tap of a finger to the box holding the wafer, the circuit turns on and off AC or DC power to an external device. The circuit is powered by a ...