Home     Contact     Projects     Experiments     Circuits     Theory     BLOG     PIC Tutorials     Time for Science     RSS     Terms of services     Privacy policy  
   
 Home      Projects     Experiments     Circuits     Theory     BLOG     PIC Tutorials     Time for Science   


<< Back to INDEX

Single Transistor Codelock [Project]
posted September 25 2014 16:55.13 by Giorgos Lazaridis




Its not the most sophisticated security system in the world. Its not even close to modern. But we have to admin that it is brilliant. And in some cases its more secure than a simple codelock.

A number of buttons in prallel (3 in this circuit) are used to pull the base of the load transistor directly to the ground. A number of buttons in series are used to pull the base HIGH through a resistor. So, if the operator pushes simultaneously all the series buttons, the base will be pulled HIGH and the transistor will be driven to saturation, powering therefore the load.

If ANY of the parallel buttons is pressed, the transistor will be driven to cut-off. The transistor cannot turn on in that case.

10/10 for the idea.


[Link: electronicshub]
 
Share



You might also like...


Make Your Own High Power Flyback Transformer [Project]

Autonomous robot navigates using collisions [Robots]

Single transistor audio Preamplifier works well indeed! [Project]

Automatic Fish Feeder Machine [Project]

DIY Canon fires bowling balls [Project]

Dr Brown's capacitor ESR tester [Project]

Rubik's Cube Solver [Project]

How a Joule Thief Works [Science]


<< Back to INDEX



Comments

  Name

  Email (shall not be published)

  Website

Notify me of new posts via email


Write your comments below:
BEFORE you post a comment:You are welcome to comment for corrections and suggestions on this page. But if you have questions please use the forum instead to post it. Thank you.


      

No comment yet...

Be the first to comment on this page!












 Contact     Forum     Projects     Experiments     Circuits     Theory     BLOG     PIC Tutorials     Time for Science     RSS   

Site design: Giorgos Lazaridis
© Copyright 2008
Please read the Terms of services and the Privacy policy