Electronics Theory and Tutorials
Schematics of delabs
- Circuit Diagrams, Design.
Tutorials, Theory, Fundamentals
Design Notes and Answers.
Theory and Tutors in Electronics and Instrumentation :
Learning electronics in theory by studying books is the
conventional way, this method may help in History and Maths. Maths
needs a paper and pencil
for practicals and history needs
a well equipped Library. In these modern times, the web has made
access to wide range of learning information easy, which is true
Knowledge Empowerment. The greatest gift a Child can get from
the Parents or School, is Knowledge.
As an Electronics Engineer i had always needed data sheets and
application notes. The web makes these documents
and learning resources
not only accessible to all, but
Now coming back to Maths and History;
a computer, some programs and the Internet can create a
"Practicals" for these Subjects. In case of Mechanical,
Electrical and Electronics it is not so simple. You need to have
many components and some test instruments and most important; a
to build-n-learn practically.
Process Control Instruments
These are some instruments i manufactured when i used to run
my own industrial automation business.
Some youngsters learn by breaking and fixing, toys and gadgets.
Many learn by Making Home Garden Projects from Kits after
, this is a better way of learning. I started
with DIY Science, including Magnetism
rather than Electronics. I could work
with an Iron only in High School.
Now many Virtual
Electronics Workbench Software
and Interactive Tutors are
available, these aid learning. We have to design, build and
apply some electronic ideas in 3D Hardware, for complimenting
the Book, Academic or Web learning. Practical and Theoretical
study in electronics has to be in Tandem, this is possible only
when Industry works with Universities to create real talent and
skills in students. The applied technology is evolving, hence
the academic education must be relevant when the student gets
into his first job.
Here are circuits made of Resistors, Capacitors and Inductors
which are passive components. Crystals, Thermistors,
Varistors, Variable Passive RLC are also Passive Parts.
Circuits using only
discrete devices and here are some basic Electronic Tables and Charts
Zeners, Diodes, NPN-PNP Transistors, FET, MOSFET, SCR
Triacs are all discrete active devices. ICs and Hybrid Modules
are made of many discrete and passive components. In the
Integrated Circuits or ASICs, all parts even passives are
derived on the Silicon Wafer. In Hybrid Modules the construction
uses SMD or Tiny Chip components interconnected in a small
ceramic PCB and Hermetically Sealed if needed.
Parts like Switches, Connectors, Relays and PCBs are
ElectroMechanical parts. Nuts, Bolts, Screws, Cabinets and
enclosures are Mechanical parts.
For a Systems Integrator or Control Panel Designer, the Timers,
Controllers, PLC which are Electronic Products become
Components or Modules along with Contacters, Current
Transformers, AC-DC Drives etc.
Learn about the Types of Components
Design Notes - Components Selection
(These are notes jotted down in the 90s, it may have spelling
and other errors)
Selecting the parts for your product design, choosing the
components intelligently is a part of Product
Budget, Availability, Size, Alternate Vendors, Product Life
and Quantity to be manufactured are some factors that
determine the selection of a prudent and experienced design
To choose the right type of part, an exhaustive knowledge of
the behavior of passives and discretes is essential. Some
points i remember among the things that i learnt the hard way
are listed below.
"when you solder the windows should be opened, cross
ventilation must be good, because the fumes are not very good
for health. After you finish wash your hands with soap, as
lead is poisonous or toxic"
- Over rate components at least double, if you need a
1A-100V-100uS diode, use a 2A-200V-50uS diode.
capacitors have a shelf life, if you need to store
them you have to charge them every month.
- Gold plating is used in connectors because it has low
contact resistance and does not corrode or react
- Use a 100uF and 0.1uF CD in parallel to filter because the
inductance of 100uF is a lot (the electrodes are wound as in
a coil) and high frequency passes over and is filtered by
the 0.1uF which has negligible inductance.
- Ceramic capacitors leak a bit, electrolytics leak a lot
but plastic or mica capacitors do not leak at all, near
perfect. An oscillator with a RC time setting needs a
plastic cap for stability.
- In industrial electronics equipment, connectors are a
source of many problems, hence avoid connectors. vibrations,
corrosion and frequent usage will result in strange
- Small signal diode 1N4148 switches at 4nS, current of 70mA
and 70V withstand capacity.
- 2N2222 and 2N2907 form a fast switching NPN-PNP pair and
have been around for decades.
- LED displays are best indoors and are not so good for
sunlit outdoors, LCD is good for that.
- All electromechanical parts like switches, relays,
connectors and pots have limited number of operations.
- Failure of parts are when parts are stressed beyond limit,
bad environment, misuse, infant mortality and normal aging.
- Most pots have a dielectric insulation between metal pot
shaft and terminals of 1KV or more. Some commercial pots may
have lesser breakdown voltage and that will be a product
safety issue. So either way use Plastic Knobs or pots with
- Solderman Talks 1702 AD