When we use Triac and LDR to make Automatic Lights, a major problem arises . Lamp starts flickering during the light transition period in the evening and morning. Lamp fully turns on only when there is complete darkness and turns off only when day light is full. This simple design solves the problem. Light instantly turns on / off without any flickering. You can drive CFL, LED bulb etc which turns on automatically around 6 pm and turns off around 6 am. See the simple design. Continue reading “Flicker Free Automatic Light”
1 Watt LEDs are widely used in Emergency lights and LED lights. Most of the circuits use 4 volt battery having 0.5 to 4 Ah capacity. The 1 watt LED is rated 3.6 volts maximum so we need the correct value resistor for LED to get maximum brightness. Let us see how the LED resistor value is determined.
Continue reading “How to select resistor for 1 watt LED”
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”
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”
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”
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”
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.