LM317 | Electronic Project Circuits

Posts Tagged ‘LM317’

Lithium Ion – Lithium Poly Charger by LM317

The above circuit will charge any 2-cell * Li-Ion battery pack. Maximum current is about 650 milliamps. The circuit is designed for batteries of 900mah or higher. Note this circuit is NOT for Li-Metal batts (i.e. Duralites). Power source can be a 12v Gell cell (Power panel), or can be powered by a car’s cigarette lighter. I use an old 12v DC wall transformer (800ma or more.) Radio shack sells a 12v/1amp wall DC adapter #273-1776 that will work. Supply does not need to be regulated. In fact my cheap supply outputs 17 volts with no load.
Read More Source:http://www.shdesigns.org/lionchg.html

Be the first to comment - What do you think? Posted by admin - March 29, 2008 at 7:48 am

Categories: Battery charger Tags: li ion battery charger, lithium battery, LM317

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. To do this I used a shunt resistor and a current converter. I choose 0.2 ohm for the shunt, since it’s not hard to come by and should only drop 0.1V @ 500mA. Either an INA168 (current output) or an INA193-198 (INA194 is best in this case) (voltage output) will fit as current converter. The trip point at which the LED should start to burn can easily be adjusted by one resistor (in case of the INA168) or by two (in case of the INA193-198). In the schematic it is set at 100mA using an INA168 using a 950k resistor. The Schmit buffer is a Texas Instruments Little Logic chip (1G17).
Source:http://members.lycos.nl/anthonyvh/index.php?page=usb-charge

Be the first to comment - What do you think? Posted by admin - March 11, 2008 at 9:29 am

Categories: Battery charger Tags: ipod battery charger, LM317, USB Battery Charger

Bread Board Power Supply by LM317

uCHobbyâ€™s first electronics kit is a handy breadboard power supply. The power supply design is simple but just what I needed for my electronics projects. I have seen several similar power supply boards but none had all the features I wanted. This design was also a good first project to help me learn about Kicad.
Source:http://www.uchobby.com/index.php/2008/02/19/bread-board-power-supply/#more-104