Feeling irritated to go and switch on/off your AC, Toaster or Lights while working on your PC ? So, this simple project is quite interesting and useful for you, which can enables you to control eight electrical appliances/devices through your computer. To built this project you just need a computer, a Parallel Port (Printer Port), Some Relay (6 Volt), Transistors (BC547) , Resistor(100ohm,10K and 3.3K) and Connecting Wires and the Interfacing firmware (PC Control.exe).

    Assemble the circuit as per the circuit diagram on a PCB or general purpose board. connect it to the PC through the parallel port and run(PC Control.exe). From PC Control Interface you can control the devices connected to the Relays.