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

Friday, September 11, 2009

Digital code lock



This is a simple but effective code lock circuit that has an automatic reset facility. The circuit is made around the dual flip-flop IC CD4013.Two CD 4013 ICs are used here. Push button switches are used for entering the code number. One side of all the push button switches are connected to +12V DC. The remaining end of push buttons 2,3,6,8 is connected to clock input pins of the filp-flops. The remaining end of other push button switches are shorted and connected to the set pin of the filp-flops.




The relay coil will be activated only if the code is entered in correct sequence and if there is any variation, the lock will be resetted. Here is correct code is 2368.When you press 2 the first flip flop(IC1a) will be triggered and the value at the data in (pin9) will be transferred to the Q output (pin13).Since pin 9 is grounded the value is “0” and so the pin 13 becomes low. For the subsequent pressing of the remaining code digits in the correct sequence the “0” will reach the Q output (pin1) of the last flip flop (IC2b).This makes the transistor ON and the relay is energised.The automatic reset facility is achieved by the resistor R11 and capacitor C2.The positive end of capacitor C2 is connected to the set pin of the filp-flops.When the transistor is switched ON, the capacitor C2 begins to charge and when the voltage across it becomes sufficient the flip-flops are resetted. This makes the lock open for a fixed amount of time and then it locks automatically. The time delay can be adjusted by varying the values of R11 and C2






Notes.

* Assemble the circuit on a good quality PCB.
* The circuit can be powered from 12V DC.
* Mount the ICs on holders.
* The L1 can be a 12V, 200 Ohm SPDT relay.
* Capacitor C1 should be tantalum type.
* The C1 and C2 must be rated at least 25V.

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