Category Archives: Engineering

Dimmer Using TRIAC

Here We will discuss about dimmer circuit using TRIAC. Basics of TRIAC is not covered in detail, you can refer it on google.

Diagram 1 above shows basic construction and symbol of TRIAC.

Diagram 2 shows Working Quadrants of TRIAC. Safe quadrants of working are Q-1, Q-2, Q-3  and we should avoid Q-4 as Gate current required to trigger TRIAC is much higher compared to other three quadrants. di/dt also reduces thus TRIAC may damage early.

Circuit shown below is Dimer using TRIAC:

In this circuit, firing angle of TRIAC is adjusted by R-C time constant. here we have connected GATE terminal to MT2 so TRIAC works in 1st and 2nd Quadrant thus avoid 4th quadrant of operation.
In +ve half cycle capacitor C1 charge through R1 and R2 (upper plate +ve). when capacitor charges full and reaches Vbo of Diac D2, Diac starts conducting giving +ve supply to the TRIAC. TRIAC starts conducting and capacitor discharges. as soon as supply voltage reaches zero TRIAC stop conducting. In -ve half cycle capacitor charges with upper plate -ve and gives -ve supply to TRIAC gate through DIAC and cycle repeats.
When load is Inductive it supplies back energy stored in the coil into supply rail. this scenario can backup C1 which then evolves into not able to charge correctly. C2 assist C1 to keep up it’s cycle by offering bursts of small voltage even though C1 has totally discharged. thus keep the proper switching rate of triac.
By Varying the POT we can vary firing angle of triac thus controlling the Voltage output.

 

Graphene battery-future of batteries is now !

Graphene is 2D structure of Graphite from which our pencil is made up of. Two scientist A Geim and K Novoselov at the university of Manchester created the first sample of graphene by polishing Graphite with tape and they notice extremely thin flex stuck to the tape as a result graphene was born. In 2010 they got Nobel Piece price.
2D structure of Graphite called graphene unlocks many great features, it is 1000 times stronger than steel, transparent, flexible, environment friendly, extremely light and best conductor of heat and electricity. these properties are perfect for battery.
Using Graphene for batteries reduces size by great extent compared with similar capacity Lithium ion batteries, Charging time reduces by 60%-70%, these are cooler than any other batteries, charging and discharging cycle increases twice as of li-ion batteries and mainly graphene is environment friendly non toxic material.
the down side is the only, these are very complex expensive to manufacture for now. but in future it will reduce as many competitor will come in and advance manufacturing processes will be developed.
Graphene has limitless uses, some of them are Water filter, Air filter, Bulletproof jacket and so on…

“ॐ voice prosthesis” ₹50 Speaking device for a throat cancer patient.

“Speech is right not a privilege” Oncologist Dr Vishal Rao.

He explained “It is simple voice prosthesis device that fits into the throat of a throat cancer patient (4th stage)
It cheats the brain to tell it all is well, and food pipe vibrates like voice box and makes the patient speak again.”

ॐ voice prosthesis is very simple to deposit into patient throat, it takes only 30 seconds.

Other speaking devices are available at  ₹30000 to ₹1.5 lakh

 

Video : https://www.youtube.com/watch?v=aWj1Rl1yk98

Good news for Arduino users, an arduino board that shows up as a disk drive!!!

here’s something you’ve never seen before? – an arduino board that shows up as a disk drive, so you can drag and drop files that are stored on SD or SPI Flash over the USB connection. makes transferring assets like audio files, fonts, images, gifs, datalogs, etc as well as configuration scripts SUPER EASY! Install Adafruit SAMD 1.5.0 board support package with TinyUSB stack support and the the example code here:
https://github.com/adafruit/Adafruit_TinyUSB_Arduino

and video!
https://youtu.be/0bWba0PU4-g

works with: SAMD21 and SAMD51 boards (also nordic’s NRF52840).

adafruit recently did a bunch of work to create an open source, cross-chip USB stack that will let anything with USB peripheral/host use the same USB CDC, HID, MIDI, MSD (etc) code.

How to save vrml(.wrl)-3D file as 3D pdf using Photoshop cc***

Now days we all see 3D pdf files which are very useful to share across cross platform and does not require any special paid application/ software to open 3D file.

Creating 3d pdf is very easy using photoshop cc in just three easy steps,  I use it to create 3D pcb pdf from exported vrml (3D file) using diptrace (pcb creator software).

STEP 1. Open Photoshop cc in File menu click open and select 3D file (vrml) from file location.


STEP 2. Now go to 3D menu on top bar, select and click Export 3D layer…

STEP 3. then in dialogue box select 3D file format as 3D PDF. click OK and done…

3D PDF:

World’s Most Expensive Anniversary celebration by “Bugatti”

Bugatti Celebrating 110 years of the brand also 110 years of Jean Bugatti himself, with worlds most expensive car till date. worth  16.7 million euros which are convert to Rs 131.33 crore in Indian currency (the amount includes the price of the car along with the taxes) called Bugatti La Voiture Noire.

Bugatti La Voiture Noire is absolute elegance

La Voiture Noire is a reminiscence of Type 57 SC Atlantic. Built by Jean Bugatti, Type 57 SC Atlantic is one of the most valuable classic cars in the world. Only four Atlantics were made between 1936 and 1938, each of them with detailed differences created individually for a customer. Three of these extraordinary coupés are still in existence.
“Every single component has been handcrafted and the carbon fiber body has a deep black gloss only interrupted by the ultrafine fibre structure. This is a material that has been handled perfectly,” Bugatti designer Etienne Salomé said.
La Voiture Noire is powered by a W16-cylinder engine with a displacement of 8 litres that develops 1,500 PS of power and 1,600 Nm of torque. There are six tailpipes at the rear.
Only one car is made and already sold out, company does not reveled name of the owner.

Have a look@YouTube

“Shakti”, Fully Indigenous micro processor from IIT – Madras

We all know or heard Intel, Qualcomm (Snapdragon Processors), AMD, ARM processors. We use them in our daily life. The all are from foreign countries. Now India started Manufacturing own micro-processor Called Shakti. The Shakti project was founded in 2014 as an R&D project aimed at building Power ISA chips. The project then shifted to RISC-V.

The SHAKTI project is building a family of 6 processors, based on the RISC-V ISA (RISC-V: The Free and Open RISC Instruction Set Architecture). RISC-V ISA delivers a new level of free, extensible software and hardware freedom on architecture. Intel and ARM uses there own architecture x86 and ARM respectively.
Shakti currently have three Base core variants as the E class, C class, I Class and Three Multi-core Variants as the M class, S class, H Class.
C class Processor fabricated by Intel based on 22nm technology named RISECREEK, and another varient is fabricated In India by SCL(Semiconductor Laboratory- Department of space, Government of India) based on 180nm called RIMO.
What Makes Shakti different from all other processor Intel, ARM never share there architecture but Shakti uses Open-Source architecture so this makes processor development as per the user need. Shakti Uses Harvard architecture (Uses different bus for Address and Data). whereas most of the processors uses Von- Neumann architecture (Uses Same bus for Address and Data). this gives performance boost to the Shakti processor.

The Shakti project booted Linux on its first RISC-V processor. The 22nm FinFET fabricated, 400MHz Shakti chip can run at 1.67 DMIPS/MHz, and will be commercialized by a startup called InCore.

Great Physicist Stephen Hawking Using eLocutor to communicate with World, It is an open source software made by “Arun Mehata” in India.

Prof. Stephen william Hawking will remember for work on Black hole and the origin of the Universe. To under stand his theory we need more 50 years. At age of 20, he pursued a PhD at Cambridge University.

At 21, he was diagnosed with Lou Gehrig’s disease and at age of 43 he permanently lost the ability to speak. then he started using computer synthesizer for voice communication, In visit to India he awarded the first Sarojini Damodarn Fellowship by the Tata Institute of Fundamental Research.

Arun Mehta is an Indian software developer and disability activist. At the request of Stephen Hawking (age 63), He, along with Vickram Crishna Developed custom made software for him that could predict what he wanted to type. It is free and open source software named eLocutor.

eLocutor was designed for Prof. Hawking to allow him to Type, Speak, and Command the computer. Their ability to communicate with the world hinges on software that allows them to efficiently enter text into a computer and have it spoken for them, only through the operation of this single button.

50Hz frequency used in India, Not 20, 30, 120 Hz Why?

We uses 50 Hz because England has control over India and England uses 50 Hz frequency because It is a sweet point of other frequencies, Lowering the frequency will Increase Size and weight of transmission line and Increase in frequency Increases Losses. So in the time of Second World war Requirement of copper is increase for making Ammo. Hence they can not use Lower frequencies as the cost increases and Transmission losses can not be bare by Increasing frequencies hence Started using 50Hz.  This is Trade off between Transmission loss and Transmission cost.

 

 

Why Transistor Called Transistor?

Before Transistor there were Vacuum tubes which are bulky and fragile, To replace them Transistor is Invented In Bell Lab.

The committee within Bell Labs that was set up to standardize terminology across the company were unable to decide on a name for it, so, they held a ballot across the entire company to vote for the name. “Semiconductor triode”, “Surface States triode”, “Crystal triode”, “solid triode”, “Iotatron” and “Transistor” were the choices. “Transistor” won the ballot.

The Name Transistor is Derived from “Transfer of Resistor”

Transistor has two p-n junction, One is forward bias have low forward resistance and other is Reverse bias have high forward resistance hence Signal flows from Low resistance path to High Resistance path called Transfer of resistance.

To Under Stand the Transistor, Simple example of Water tap. As Shown in the Diagram Water flows from the Emitter to Collector and water flow controlled by the gate.