ATTRACTIVE MAGNETIC LEVITATION

A principle of operation of a magnetic levitation system is quite simple. If you sense that the magnet is moving down because of gravity pull it up by the attractive force of electromagnet. If you sense that the magnet is moving up because of the force of electromagnet reduce the attractive force of electromagnet so that it moves down. Now you keep doing it continuously so minutely and fast that human eye perceive that the magnet  is floating in mid air. Actually the magnet is moving up and down very fast at very small displacement. If you continue to attract the magnet using the electromagnet it will continue to move up and finally stick to electromagnet. So as soon as you sense that the magnet is moving up you reduce the current in electromagnet so that its attractive force decreases. Now as the magnet starts to drop down you increase the current  in the coil so that its attractive force increases and you pull it back.

REPULSIVE MAGNETIC LEVITATION TRIALS

Trying repulsive magnetic repulsion with Nagasai, Ruchik and Hemant. Looks like magic.

PLANE CRASH

While my stay in IISc we made a attempt to build a RC plane. All fun, just play the video.

SLAVE FLASH FOR LOW END MOBILES

This product is a solution for mobiles with camera and audio port but no flash. The quality of low light images can be greatly improved by the use of slave flash. A

'click' sound is produced when you take picture by mobile. This sound is used as a trigger signal to slave flash through audio port. The signal is given as trigger signal to IC555 in monostable mode. The monostable output is used to drive the slave flash i.e. power LED's through ULN2803 driver. 

LASER DRAW

Hi folks !
This is yet another attempt to make a laser projector. This device records the motion of your pen using IR mouse chip ADNS 2610 chip from AVAGO and stores it in RAM of P89v51rd2 (1kb) .And can reproduce the X-Y coordinates with a accuracy of 1mm ,technically the mouse has an resolution of 400 cpi (count per inches)which is more than sufficient, delta x and delta y registers are continiously read and displacement if found is stored in RAM .The current prototype can record 40 inch motion, recorded motion is reconstructed using two DAC0808 one for X and one for Y.the speakers can reproduce sounds up to 20 Khz however we require a refresh rate of just 20 Hz ,however the amplifier between x/y output and speakers is still under construction.sorry for poor quality video.

DIY LASER PROJECTOR

This is our final year project "laser text projector" capable of projecting 16 characters at a distance of 1 meter and some animation under low light conditions .The micro controller used is of 8051 family P89v51rd2fn from philips .The main reason for using this micro controller is that its programmable through serial port of your computer ,thus finding a bug is easy as you don't have to remove the ic again and again.The machine language programming is done using Keil and IC is flash programmed using Flash magic . Circuit design modules were first individually tested on breadboard and final layout was generated using Orcad 9.2 .

Principle of operation: This laser projector works on the principle of persistence of vision. To   phenomenon, sweep a laser pointer just left to right fast enough to define a line. If you switch on and off the same laser you will get a dotted line. Now in the projector we have steeped 8 such laser beams and amplitude modulate it to define a matrix of characters.

Observe the videos carefully to understand the principle of working.

ROBOWARS

Just for fun.