My learning or old design notes are archived in Soldermans
. Before that it was published as Amps-n-Volts my Web Mag + email newsletter ( less than 200 subscribers). Now i remember some design aspects after seeing some circuits online, so i will jot when i get some EE Tech Metrics
, Prototyping or Production. See Schematics
circuits too. Design Notes Index
is a blog on Industrial Automation.
I designed many Process control instruments when i was employed. I used to work in sometimes cramped and noisy environments.
had a huge Fluke Calibrator sitting next to me, it was overwhelming. I
even replaced his 50 ohms when a engineer accidentally applied 24 V into
Keep training as a very important part of firms, when the seniors teach the juniors all the basic aspects and precautions.
When you are young the capacities are more but experience is less. As we grow older it is vice versa, unless we keep fit.
Now we have smps in most everything. AC Adapters and CFL lamps and many Home Consumer Electronics. The Failures of these units are on the rise. The Cooper transformers are out, but the SMPS reliability is falling.
Designing and manufacturing a SMPS facing a 230V input constantly, is not easy. You cannot Mutz your way in this, in a cost-cutting spree of this Vital Organ, just to have a competitive advantage of 'a lower cost product' (read cheap).
Now 230 V AC 50 Hz is not what you think it has, it has EMI-RFI, Inductive Kickback Spikes from the neighborhood, resonating and ringing with the RLC network that your home wiring forms. Lightning and Atmospheric Static that may strike at the weakest part on the SMPS. Wrong wiring, 3 phase mess ups. short circuits, falling tree branches, thunderstorm. Your SMPS is facing the Real Harsh Cruel world and the best part, they left off the Security Department to keep costs low. The critters in the box get zapped for no fault of theirs.
There is one difficult way out of this, we move to a 24V DC standard within the house, it is safe and the Box outside the house faces all the Electrical Environment Variables and Unpredictability. This box that charges the battery and steps down the mains voltage can be protected well. Protection on this one unit, protects all the equipment in the Home or office. This is the Civilized way electricity should be used in Homes and Offices. Easy to integrate with Alternative energy. Factories can have all the High Voltage they want.
These days most of the Hardware is coming from china. When a good technical collaborator is involved, quality is given due respect, the products are affordable yet robust. Some unfettered (quality) units and firms all over the world, mainly china, cut off vital circuitry (these happen in mechanical, electrical and chemical field too) to keep the product cost low. These products will work well in a Mains conditioned environment which is only affordable in some companies and never at homes.
The Security system consists of something that a Surge Protector from Belkin has. Let us see the traditional way, We need Gas Discharge Tube Lightning Arrestors. Then Varistors, Thermistors, X and Y caps and the Common Mode Choke Coils. A high voltage and high current fast acting fuse or trip circuit. Overrating of Mosfet and caps that face the high voltages. Using HV Back-to-Back zeners with fuses. Snubber Plastic HV self healing caps and Fast Switching diodes to absorb the inductive spikes.
Do it within the budget you have. SMPS should withstand 1.2KV microsecond pulses. 600V millisecond pulses and 400V for a few seconds. 300V AC for many minutes. Else let us go 24V Standard.
Other Protection devices your house or lab may needs to have. CVT - Constant Voltage Transformer, 1:1 Isolation Transformer, Servo Motorized Auto-transformer Stabilizer, Earth Leakage Circuit Breaker, HV-Relay Trip Circuit, Overload Current Relay Trip Circuit, MCB, Switched Triac or Relay, Copper Transformer Stabilizer with Layer or Layer Primary Insulation to protect against high voltage. This transformer should have earth shield, guarded terminals, primary windings should not slip layers, Vacuum Impregnated.
May the Earth be good to you ! - Means - the earthing in your Home of Office should be excellent and do not compromise on Wiring Insulation and Switchgear. Let the wires outside have concrete gutters which are closed so that water or rodents do not get to the cables.
Read more at my Power Electronics Section
Intellectual Property - IP - Business Model
# High Tech Company should have two independent & isolated profit
centers or companies a Global Entity & a Local Entity. IP &
Products Unique. Wednesday, September 01, 2010 9:20:31 AM via web
Protect, Enhance, Maintain & Monetize your IP (Intellectual
property). It could be Hardware, Process, Software or Research. Here's
Trouble. Wednesday, September 01, 2010 9:12:00 AM via web
Technologies should scale with Infrastructure. Buildings cannot stress
the Foundations meant for. Traffic proportional to Road Width. Sync .
10:00 AM Jul 23rd via web
About Uncle Sam
America has to be Healthy. Once heard, Me modify - If US Sneezes, EU
catches a Cold, Emergent Economics get Pneumonia. Keep US in form !
9:35 AM Jun 20th via web
# Tech Expertise & Reliability
Gradient : 1st-Europe+Russia; 2nd-North America+Japan; 3rd-Taiwan+Korea;
4th-Brazil, China, India..; 5th- Oth. 9:03 AM Jun 20th via web
The Midas Touch of US has been directly or indirectly responsible for
this gradient of both technology/economics and its reverberations. 9:27
AM Jun 20th via web
Some Ideas of mine that were put in delabs Tweeter, related to EDA and Product Design
Product Design Optimization
Make Practical (it works), Affordable, Usable (ergonomics), Safe, Reliable (robust), Durable/Consistent & Maintainable (Servicing)
Dust and Contamination in Connectors
Once i opened a RF Millivolt Meter of Marconi Instruments. It did not have a spec of dust inside, not even one micron size of dust
Connectors exposed to Environment should not only be Corrosion resistant but also Dust, Grime & Insect Proof! Dummy Covers on
Air Vents, Fans & Unused Slots in Modular Instruments. Missing Fasteners in cabinets, gaps in panel components collect Dust &
Dust + Moisture + Smoke + Pollutants = Conductive Grime Deposits on PCB, Parts & in-between the IC pins. Can Simulation include this
Virtual Environmental Testing a part of simulation and EDA, just like Mechanical Modelling and Studying Thermal Gradients on PCB.
If a product gives three years life with minimum service support it can save itself from building a bad reputation. six years will establish the brand on a long term basis, twelve years of product life you will have the user of the product selling for you.
if you want to improve sales by giving a new model every three years, you will need a lot of innovation on the product and you need to buy back the old ones for a big discount, you can bear some cost for brand loyalty and hence build a reputation for more sales in the future.
- San 1999
Sometimes a Spartan R&D Engineer needs to know more ...
When you design a new product, we can design it with new types of parts, but it is also important to use parts that are standard to the company's inventory, Also you need to use up the parts which have been accumulated due to a discontinued product line or a failed idea.
This way the design becomes more frugal and efficient. And the inventory valuation more accurate. It also saves the company to build a new part type stock. And finally a balance sheet which is realistic.
What is good for the firm, is good for you.
- San 2002
Just like in TV or Tape Recorders all products must be in three variants. this applies to software, hardware, services etc..
The most important variant is the low cost durable variant, uses time proven technologies, this is sold in large numbers, it streamlines the manufacturing and other processes, it announces the product-brand-company far and wide.
The second variant is priced higher, has more advanced features, uses new technologies, needs more customer support and serves the purpose fully in a cost-effective manner, this is the standard product.
The last variant has many bells, whistles and flashers, this is priced very high, personal human customer support will be involved, it has many luxurious features which may be decorative but may serve no useful purpose. it could even be custom altered or designed. it will also serve as a status symbol for some.
The conclusion is that all types of customers are served, the company makes decent revenue, and a company can be built and sustained on long term basis.
It is the same product with more or less accessories, features or capabilities to suit all budgets. Modular and Extensible.
- San 2003
If Inputs are Distorted, The Outputs are Noisy.
Even if the Amplifier is Very Good.
If Raw Materials are of Poor Quality, The Finished Goods are Defective.
Even if the Process and Machinery is State Of The Art.
If the Specifications are incomplete, The Prototype will be rejected.
Even if the Design and Tools are Perfect.The Infinite Quest
- The Endless Search Adventure of San
An Engineered Equation( technologies + skills + processes ) X ( monitored + managed ) = engineering.
an old equation i made, not yet validated
Keep Designs Simple
Circuit or Code - Keep it Simple, Modular, Reusable, Documented, Controlled, Compact, Clear, Creative, Maintainable, Testable, Tunable.
The 7S - Software Should be - Simple, Stable, Spry, Slim, Scalable, Sensible, Scrimping.Incremental Coding
I do incremental coding - code few lines, test, code again, test. Some extra code to interface for test inputs/outputs (virtual instrument). Incremental Coding, Modular. Test Points.Tools Theory Practice
Excellent Tools alone are not enough, The Techniques & Methods have to be learnt, Then the Skills have to be acquired by Strenuous Practice.
The Axial capacitors like Metalized Polypropylene MPP are more reliable
in comparison of their radial counterparts of same voltage rating.
note 440V AC Continuous rating reads and translates differently than
630V DC Max. Overrating is an important step in reliability for
Radial plastic caps, in mass production, due to
various inconsistencies in production or quality measurement, are not
recommended for high voltage unless its is a Manufacturer known for long
term reliability and quality track record.
The radial caps when
being wound, stretches the film/dielectric or weakens the dielectric at
some areas as the turn is sharp, top/bot. This is possible unless the
winding machine relaxes strain around the turns. In a Axial that may not
be a problem as the film has more uniform stretch. The other reason
could be that the Film is wrapped a little on corners or compressed on
epoxy impregnation. It could also be low quality non-uniform PP
Components Manufacturers, especially in china have to
spruce up a Raw-Material and Component Quality, not by red-tape but by
actually improving the manufacturing and procurement processes, as the
quantities involved are huge.