Low Power LED Voltmeter by LM3914 This is a low power voltmeter circuit that can be used with alternative energy systems that run on 12 and 24 volt batteries. The voltmeter is an expanded scale type that indicates small voltage steps over the 10 to 16 volt range for 12 volt batteries and over the 22 to 32 volt range for 24 volt batteries…

Level Detector by IC LM741 This circuit be the circuit checks voltage is easily. Or Level Detector by IC LM741 highly popular. By R1 keep fine the value voltage referable of the circuit. If Vin be valuable more than volt. The referable LED stick bright….

Blown Fuse indicator LED Display A Fuse be the equipment protects that use often most. Because of cheapness can use protect electronics expensive circuit. Generally when fuse torn us can know immediately. but in sometimes Fuse torn already we don’t know. such as in electricity automobile system brake system , the system delays the electric current very much, etc…..

USB-Powered Lithium-Ion Battery Charger by LM3622 The battery-charger circuit is designed to operate as a high power USB function. To be compliant with USB Specifications (Rev. 1.1), a high-power function must not draw more than 500 mA from the bus during normal operation. The LM3622 uses the 0.25 current-limit resistor R1 to set a 400 mA maximum charging current……

USB Powered AA NiMH – NiCd Battery Charger by LM393 The charger in this project is designed to charge two AA NiMH or NiCd cells of any capacity (as long as they are the same) at about 470mA. It will charge 700mAh NiCds in about 1.5 hours,….

USB iPOD Charger by REG1117A The circuit’s pretty simple, basicly it’s just a voltage regulator. Both the LM317 and the REG1117A (LDO) fit the PCB, maybe there are even more types that I’m aware of that can be used on it. I did add one extra thing: a LED that shows if the connected device is consuming power…..

Ni-cad battery charger with DC power supply 9V The Ni-cad battery charger circuit can be used with the battery will charge with 4.8Volt current 800mA using it for about five hours, “which serves R1 limit the current flow. To the Ni-cad battery charger circuit where the R2 and LED1 is told that the state of the battery charger ….

Dry Cell Battery Charger using LM741 and IC4011 This is Dry Cell Battery Charger Circuit. That can use charger battery get that about 12 hour. When apply to power supply 9 volt the equipment that fix in the circuit use for size battery AA. If use the size C or D should devalue of Resistor….

USB Li-ion battery charger This is a charger for lithium ion batteries which takes its power from the USB port of a computer. It uses the MCP73861 or MCP73863 Li-ion battery charger chip manufactured by Microchip. The circuit board is a piece of single sided copper clad board. A hole is cut inside it so that it will accommodate the integrated circuit…..