The Open Door Web Site
HOME PAGE BIOLOGY CHEMISTRY PHYSICS ELECTRONICS HISTORY HISTORY of SCI & TECH MATH STUDIES LEARN FRENCH STUDY GUIDE PHOTO GALLERY
 

ELECTRONICS

Google
Custom Search
The EABJM Electronics Club
I started the Electronics Club at Ecole Active Bilingue Jeannine Manuel some time back in the 1980s and we continued up till around 1999.  
It was an after school voluntary activity intended to introduce students to the world of electronics through the construction of projects like a sound operated switch, a simple radio receiver etc.  
In the beginning it was the students themselves who suggested what they would like to make and we sat down together and worked something out.  
After a year or two of this I decided that it was worth collecting together all the circuits and here they are, or, at least, some of them.  
My main aims were  
a) to evolve designs which used an absolute minimum of components and  
b) to limit myself to using components, the operation of which could be relatively easily explained to beginners.  
   
The circuits have all been tested though there might remain slight errors in some of the diagrams; check before proceeding... you have been warned!  
The circuits are my own designs except  
i) the two transistor reflex radio  
ii) the led flasher  
iii) the 10Watt audio amplifier  
iv) the stroboscope  
   
The radio was designed by G. W. Short and published in The Radio Constructor magazine back in 1968 but it remains one of the best, most reliable, simplest designs for an a.m. radio receiver I have ever found.  
The led flasher was (I think) a suggestion from a reader in the magazine Wireless World.  
The 10W amplifier was (I think) taken from Transistor Audio and Radio Circuits published by Mullard.  
The stroboscope was published in a French electronics magazine, Elex.  
In these projects, the printed circuit board design is my own and some of the component values may have been modified slightly.  
Rather depressing to note that all these magazines have gone the way of the dodo and I'm not even sure if the Mullard company still exists...  
   
A final point to keep in mind: these circuits were developed for amusement only, they won't save you any money!  
This is even more true today (15/08/2017) than it was when they were put together.  
Almost anything you can build using separate components can be done more cheaply (and probably better) by an appropriate integrated circuit.  
   
Having collected together all the projects, I decided to write an introduction to some of the basic components and ideas necessary to understand how the circuits worked.  
One obvious limitation of this introduction is that it was written with one or two specific pieces of apparatus in mind; notably, a kit containing pre-wired AND, NAND, OR gates etc.  
However, it is hoped that the basic ideas about resistance, capacitance etc might be helpful  
   
One project that I was rather pleased with was an automatic pcb drilling machine.  
This took me years to complete (with the help of a friend, Bob Walker, who just happens to be a precision mechanical engineering genius) and when it was finally up and running, we videoed its inauguration.  
There's also an introduction showing some of the club members working on their own projects.  
I can't help inserting this video here... for the nostalgia!  
   
   
   
Using Veroboard  
I found that a 4mm drill bit (hand held) is suitable for making cuts in the copper strips.  
To save space on circuit boards I found it useful to drag some solder from one copper track to the adjacent track (rather than using a wire on the other side).  
I show this by an elliptical "blob" on the copper side vero diagrams.
   
Making Simple Printed Circuit Boards  
If you do not possess the equipment for making pcbs the "professional way" ie photographically, here is a suggestion.  
Take the copper covered board and cover it with some of that thin brown plastic tape which is often used in packaging (or something similar).  
Print the pcb layout onto a piece of adhesive paper (the sort that is used to print addresses for sticking on envelopes).  
Stick the paper on top of the brown tape and use a sharp cutter to cut away the paper (and tape) in order to expose the copper you want to dissolve away.  
It works well for fairly simple pcb layouts.  
   
David Hoult 2017
SITE MAP
WHAT'S NEW
ABOUT
PRIVACY
COPYRIGHT
SPONSORSHIP
DONATIONS
ADVERTISING
 

© The Open Door Team
2016
Any questions or
problems regarding
this site should be
addressed to
the webmaster

David Hoult 2017

Hosted By
Web Hosting by HostCentric

 
SiteLock
 
 
Electronics Index Page