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Showing posts from June, 2017

Protected Switching Power Supply for Development Boards

When I was prototyping a circuit in my college, one of the ground wire accidentally touched the positive of the power supply unit (PSU) and there by causing major damage to breadboard and PSU. This made me to develop this device that would avoid such accidents.
This device uses LM2576 a switching regulator, LM317 a linear regulator, and ATMega8A for controlling the power supply unit. As this needs a real time protection, I have used OS for real time simultaneous protection.
Protected Switching Power Supply:
The block diagram of this device is shown below

The AC step down transformer provides isolation from AC grid, the bridge rectifier and capacitor bank removes ripples to large extent, however small amount of ripples is present and this is not good for micro-controllers. In order to eliminate those ripples LM2576 is used. There is local linear voltage regulator to power the MCU, it also drives the relay and indicators.
Why Operating System?

As I need a real time protection from short …

SSH Raspberry Pi 2 in Ubuntu

I am raspberry pi 2 beginner and Ubuntu user, I did not have monitor, keyboard and mouse, so how do I connect and get started? Well I surfed the web and could not find satisfactory results.
If you have searched for the same query, you will be coming across "ssh raspberry pi or headless connection of raspberry pi" and "finding the IP address of RPi". For this again you will be needing tools or monitor, keyboard and mouse. Well this post will direct you to connect RPi to your Computer/PC running on Ubuntu or SSH without these tools.
When you boot RPi with Raspbian OS, the "avahi-daemon" is already installed, this will provide the access to RPi with domain name <hostname>.local. Your hostname can be found in preferences>Raspberry Pi Configuration. The hostname might by abc_xyz (just an example), but in domin name it will not contain any special characters like '_', '-',... etc.. Therefore it will resemble: abcxyz.local
Computer/PC ru…