Hydraulics !! You see them ! Now learn a bit too !!

I have noticed that even if many people do not have a electronics background but still some of them can manage  well to study electric circuit diagrams. They know resistors, lights and some  even know an op-amp.

But, do a non-mechanical background people manage to study mechanical diagrams ? No ! I don't think so. Atleast, I was not able to study any of them before the Mechatronics subject introduced in this semester of my engineering course.

Our lecturer told us to submit an assignment which he already explained. The assignment was about explaining the 'Basic Hydraulic System'. Rather then copying the assignment from anywhere else, I choose it to write it in my own terms because it was quite of a interesting stuff, and a must-have basic knowledge of mechanical system.

So here it goes!!

 

Explanation of a Hydraulic System

Figures show a hydraulic system. The reservoir is where the oil is stored. It is connected to a pump which pumps the oil. The pump is accompanied by a motor for it to function. Also seen in the figure is a MRV (main relieve Valve) which relieves the hydraulic system from high pressure resulting from excessive oil. This excessive oil is released into the reservoir.

We have a 3 position 4 way direction control valve. The control valve is ‘3 position’ because it can be set to 3 different position and at every position it executes an important task of the entire system. ‘4 way’ means that there are 4 unidirectional path through which the fluid (oil) can flow. Now let us understand each of the position in detail in context of the system.

At position one: (P1)

The pump pumps the fluid from the reservoir. The ‘One Way Valve’ ensures that the fluid travels only in one direction. The control valve is in such a position that one inlet lets the fluid in towards the double acting hydraulic ram and one outlet takes back the fluid from the hydraulic ram such that the fluid goes back into the reservoir. The pressures differences created by the fluid make the piston moves outward.

At position two: (P3)

At this position the inlet (and outlet) fluid goes to the other side of the hydraulic ram (opposite side as compare to position one). The pressures differences created by the fluid make the piston moves inward. (Opposite to position one)

At position three: (P2)

This is the neutral position. Here the fluid is blocked by the control valve so that no fluid movement can take place between the hydraulic ram and the rest of the system. This halts the piston and piston becomes stationery. This position has a great significance because a user may want to dynamically control the piston by operating the control valve. At this position a user can halt the piston at any instant of time.

Solar Tracker Based Solar Panel using Arduino

First Look!!

Hello, till date I have posted number of articles in my blog, but none on my core interest of Arduino microcontroller. This is because I’m still learning it and lots remain to be learnt. Nevertheless here is one of my very simple projects on Arduino microcontroller. I’m sure this post will be a boon for all those newbie on Arduino and equally stupid for the microcontroller experienced guys. For any questions or comments you can mail me at rishiraj.in@gmail.com or Facebook me! (Link at right side of this page)Oh, forgot to mention, this project won a small prize at a small project competition in my state

Solar Tracker Based Solar Panel using Arduino

In this post I present you a prototype of a solar tracker based solar panel. The solar panel changes its orientation according to the direction of the Sun. 

Final Prototype of the Solar Tracker based Solar Panel
Notice how the 3 sensors are kept at the Sensor Board

How it happens?

Basically there are sensors mounted. This sensor when illuminated by the sun rays gets activated and sends a signal to the Microcontroller. The microcontroller in return instructs the motor to move by the specified speed and direction.

There are three sensors fixed in such a way that each sensor gets activated at 3 instants of the entire day, i.e. Morning, Noon, and Afternoon. As the sun raises the first sensors gets activated due to ray of sun falling on it. As a result the Solar Panel orients itself to receive the early morning sunrays. Similarly the Solar panel orients itself when it is noon and afternoon to receive the sun rays efficiently and thereby increase the efficiency of the solar cell.

This dynamic Solar Panel has a greater efficiency since it can illuminate its solar cell even at the morning and afternoon time of the day.

Since it is just a prototype hence I have used torch light to depict sunlight. I made sure that the torch light illuminates only one sensor (LDR) at a time, i.e. one sensor for Morning, one for noon and one for afternoon.

Technical Aspect (Not really)

The Motor and the Sensor (LDR) is controlled by Arduino Microcontroller. The sensor has a predefined threshold value which is crossed when it is illuminated. Once the threshold value is crossed the Arduino sends an instruction to the motor to move.

To make sure that the current demand of the motor is met without affecting the microcontroller, the Motor is connected to a Motor driver (IC L293D) circuit which in turn is connected to the microcontroller.

To control the speed of the motor, PWM technique is used.

The Circuit

The image below shows the circuit, though it looks messy but trust me, it’s very simple.

Blue Wire: Connected from digital Pin 10 and 11 of Arduino to Pin 2 and Pin 6 of L293D Motor driver IC.

Green Wire: the 5V power supply from Arduino to Pin 1 and Pin 16 of IC L293D and also to all the LDRs as shown in figure.

Orange Wire: From Pin 3 and Pin 7 of IC to the DC Motor.

Red Wire: 9V external DC supply. This supply depends on the rating of the DC motor used. In my case I had a 9V DC motor hence 9V supply.

Black Wire: Common ground of the entire circuit. Pin 4, Pin 5, Pin 12, Pin 13, and Arduino ground Pin, 9V battery ground.

Resistor: I just used 100 Ohm resistor and this was chosen randomly. You can use any low resistance.

The Arduino Sketch (Code. . .)

Download It ! ! ! 
You may have to change some part of the Code depending on the intensity of the light where you keep the prototype and the intensity of the torch light used. I guess you'll do it easily, in case of any error or problem write to me.

Android Apps, A Boon for Women Security

Blame it on evil thoughts, narrow mentality or a non-integral state of mind but the facts remain undispersed. The fact that crime against women is increasing steeply and what we saw last December in Delhi was beyond the unimaginable. Blaming or starting over a new course of discussion on this issue will be of little help and the need of the hour is strong self-security measures a girl must have. This article throws a light over some specific security measures that a girl can easily undertake through her mobile phone to prevent any unforeseen incidence.

Google’s Android platform saw some new entrant on January after the gruesome incident last December. These new Android applications are free and very easy to use and access. Let’s take an overview.

1. Nirbhaya: This name is symbolic and was given to the deceased victim. This Android application sends a distress message with the location to people in a group specified by the user in emergency situation. Apart from local police authorities, hospitals you can have your close relatives on the group. You can also customize the type of emergency and assign different groups for different emergency. This application is available in the Google Play store

2. Fight Back: This application generates a security alert when user pushes a central button. The security alert and the exact location of the user are sent via SMS, Facebook and email to people specified for help. Available on the Google Play store

3. Me against Rape: Beside the feature like above this application also has some advanced add on like activation of cell phone camera and voice recorder to act as evidence against eve-teasers. It sends location coordinate to all the people predefined on the list every 10 minutes so that the user’s location can be continuously tracked. Google it !!

Follow your instincts; there is always an unnatural feeling before an unnatural happening.

(With inputs from 'digit')

Republic Day in Guwahati

I honestly don’t know if any bandh was called in Guwahati on the account of Republic day but this region of India has hardly seen any celebration on this day. Usually a boycott is called for by innumerable organization threatened with dire consequence and people choose to stay at home and laze around.

 As of me, I was lucky on this 26th Jan’13. My entire family went out for a short distance outing and we had a good time, and yes, we are safe of course safe. It is the people who can bring a change. Let any organization boycott the Republic Day celebration but the vast population of people should not. People of this region are Indians and governed by the Indian Government so why to support any such organization whose motive mainly lies in disrupting peace?

Republic day or any National day must not be restricted to Institutions and Government offices but to each and every home, each and every street.

The picture at left show some young boys cheering up the Republic Day celebration and at the right, a deserted street, typical as if a curfew has been imposed. We need more like the enthusiast in the left picture and change the image of the right picture in future.

City Bus Drivers in Guwahati -An observation

I’m a regular bus traveller in Guwahati but I usually avoid the seats near the driver because it’s hot in there and secondly the noise inside the cabin is intolerable to my ears.

Never the less, I had to sit in one of the seat near the driver’s cabin while returning from a market in Guwahati and following are my observations of the bus driver.

1. Horns from behind, horns from side and horns from left side too. I guess there is no one compared to these Bus drivers who has to hear irritating and continues honks each time they are on the driver’s seat.
2. Beside horns, they are used to hear those voices from behind like ‘rokhai diok’ or ‘rokhabo’ meaning ‘please stop (the bus)’.  Now the bus cannot be stopped at the middle of the road but errant passengers won’t understand it, they just want the bus to stop wherever they want, in case it does not happen then the driver is verbally abused.
3. The policeman comes in at the third. In this city, traffic police personnel (or any other police) can stop a bus wherever they want and fine the driver for being this and that. There are various ways (guess it) in which the bus driver has to get rid of it.
4.  Traffic Jams?? Everyone on the street will blame buses for this, passing by drivers of bikes and cars will pass lewd comment to the bus driver and drive away.

So much they bear and we never indemnify them. We also say the conductors are ill mannered, but ever realized how frustrated they remain doing the only task of collecting money and counting it the entire day?  

Be honest at the bus, pay the right fare always and don’t argue unnecessarily with the conductor or the driver. Let us live up to our virtue 