How to connect Relay with NPN and PNP transistors


Transistor is used to drive relay to connect AC loads. For efficient working, it is important to connect the relay correctly in NPN and PNP transistors. See the way of connection. Continue reading “How to connect Relay with NPN and PNP transistors”

How to fix PIR sensor Alarm


PIR sensor is the ideal device to use as Surveillance systems that operates by sensing human body heat. It triggers the alarm from a distance of 10 meters when a human passes. It operates both day and night. Let us see how to fix it on the wall
Continue reading “How to fix PIR sensor Alarm”

How to Convert SMPS to Bench Power supply cum charger



Don’t throw away the SMPS power supply when the Computer damges. SMPS is a high current device that gives different regulated voltages from the output wires. It has numerous wires to give different voltages . So you can make a good Multi voltage power supply for the Projects or use as battery charger for different types of batteries. It has total isolation from Mains and output is safe DC.
Continue reading “How to Convert SMPS to Bench Power supply cum charger”

Power Supply Box


This Power supply box can be used to interface with the High current Bench power supply made from the SMPS of Computer. The Power supply box has a DC-DC Converter cum Booster module, A Volt Meter and an Ammeter to show output voltage and current consumed by the load. Continue reading “Power Supply Box”

How to retrieve data from the Laptop Hard Disk


Suppose the Laptop crashes and is irrecoverably damaged .Its Hard disk has full of valuable data. What will do to recover that? SATA to USB device will help. Its cost is just Rs.170 and available in Computer sellers. Open the small window on the back of laptop. You can see the Hard Disk there. Unplug from its socket. Connect it to the SATA-USB socket. Connect the USB cable to PC or Laptop. It will detect the removed Hard Disk. You can open the folders and copy the data. It can be a good external hard disk in future. Continue reading “How to retrieve data from the Laptop Hard Disk”

How to retrieve data from a Hard disk.


Suppose the computer mother board crashes and the PC is irrecoverably damaged .Its Hard disk has full of valuable data. What will do to recover that? SATA to USB device will help. Just plug in its power supply and data cables to the Hard disk removed from the PC. Connect the USB cable of SATA- USB unit to a computer or laptop. The PC will detect the hard disk and you can copy the files to the computer. You can also use this Hard disk as an external hard disk.

Continue reading “How to retrieve data from a Hard disk.”