Free Electronic Circuits,Schematic Diagram,Circuit Diagrams

Thumbnail image that says sleek button using photoshop that links to a Photoshop tutoril. free, electronic circuit, circuit diagram, circuit schematic, schematic diagram, electronic diagram, audio, amplifier, power supply, guitar effect, current loop, current limiter, video, receiver, transmitter, transceiver, transistor, radio frequency, rf, active filters, digital, analog circuit, pwm, micro controller Free download

Free Electronic Circuits,Schematic Diagram,Circuit Diagrams

External links - Jqueryelectronics circuit,circuits,schematic diagram,circuit design,circuit diagram, circuit

Electronic Circuit,Schematic Diagram,Circuit Diagrams

External links - Jqueryelectronic circuit, circuit diagram, circuit schematic, schematic diagram, electronic diagram, audio, amplifier, power supply, guitar effect, current loop, current limiter, video, receiver, transmitter, transceiver, transistor, radio frequency, rf, active filters, digital, analog circuit, pwm, micro controller Free download

Best Song Lyrics Collection

External links - JqueryFind The Music Lyrics To Any Song! It's Free DAILY UPDATED! One of the largest,most accurate, browsable and searchable song lyrics source on the net. lyric, lyrics, song, music, song lyrics, music lyrics

Monday, August 24, 2009

Flashing-LED Battery-status Indicator


A Battery-status Indicator circuit can be useful, mainly to monitor portable Test-gear instruments and similar devices.









Flashing-LED Battery-status Indicator




Parts:

R1,R7__________220R 1/4W Resistors
R2_____________120K 1/4W Resistor
R3_______________5K6 1/4W Resistor
R4_______________5K 1/2W Trimmer Cermet or Carbon
R5______________33K 1/4W Resistor
R6_____________680K 1/4W Resistor
R8_____________100K 1/4W Resistor
R9_____________180R 1/4W Resistor

C1,C2____________4µ7 25V Electrolytic Capacitors

D1____________BAT46 100V 150mA Schottky-barrier Diode
D2______________LED Red 5mm.

Q1____________BC547 45V 100mA NPN Transistor
Q2____________BC557 45V 100mA PNP Transistor

B1_______________5V to 12V Battery supply





Comments:


LED D1 flashes to attire the user's attention, signaling that the circuit is running, so it will not be left on by mistake. The circuit generates about two LED flashes per second, but the mean current drawing will be about 200µA.
Transistors Q1 and Q2 are wired as an uncommon complementary astable multivibrator: both are off 99% of the time, saturating only when the LED illuminates, thus contributing to keep very low current consumption.

The circuit will work with battery supply voltages in the 5 - 12V range and the LED flashing can be stopped at the desired battery voltage (comprised in the 4.8 - 9V value) by adjusting Trimmer R4. This range can be modified by changing R3 and/or R4 value slightly.
When the battery voltage approaches the exhausting value, the LED flashing frequency will fall suddenly to alert the user. Obviously, when the battery voltage has fallen below this value, the LED will remain permanently off.
To keep stable the exhausting voltage value, diode D1 was added to compensate Q1 Base-Emitter junction changes in temperature. The use of a Schottky-barrier device (e.g. BAT46, 1N5819 and the like) for D1 is mandatory: the circuit will not work if a common silicon diode like the 1N4148 is used in its place.
Note:

* Mean current drawing of the circuit can be reduced further on by raising R1, R7 and R9 values.

0 comments:

Post a Comment | Feed

Post a Comment



.
.
.
.
.
 
TopBlogDir.blogspot.com button Top Blogs Technology Blogs Technology Blogs Add to My Yahoo! On our way to 1,000,000 rss feeds - millionrss.com Blog Search Blog Directory & Search engine LocalSubmit.com : search engine submissions and website promotion with free advice TopOfBlogs SonicRun.com blog search directory Submit your website to 20 Search Engines - FREE with ineedhits! Download Juice, the cross-platform podcast receiver
Today.com SoMuch.com: Internet Links Directory NZPAGES - Your New Zealand Web Site Directory BlogRankers.com Make Money Blogging

Search Optimization, Search Engine Optimization

A link

El directorio y buscador de Mexico Blog Search Engine Top Blogs http://www.freesearchenginesubmission.infovisiter ici Cheap Hotels Online blog directory ping fast  my blog, website, or RSS feed for Free Green-Tech blog
State Your Blog - Blog Top Sites - www.stateyourblog.com
http://www.freedomain.co.nr Increase Page Rank Cyndi's List of Genealogy Sites
 on the Internet Cyndi's List of Genealogy Sites on the Internet Search Engine Submission - AddMe http://www.freesearchenginesubmission.infoclic pour info Search Engine Marketing and Optimization

Thank U & Come Again.....


Search Engine Optimization and SEO Tools
Submit ExpressSearch Engine Marketing

FREE CIRCUIT DIAGRAMS 4U Copyright © 2009 REDHAT Dashboard Designed by SAER