My Light Diagram

If some intruder tries to open the door of your house, this circuit sounds an alarm to alert you against the attempted intrusion. The circuit (Fig. 1) uses readily available, low-cost components. For compactness, an alkaline 12V battery is used for powering the unit. Input DC supply is further regulated to a steady DC voltage of 5V by 3-pin regulator IC 7805 (IC2). Fig. 1: Circuit of the door guard Assemble the unit on a general-purpose PCB as shown in Fig. 4 and mount the same on the door as shown in Fig. 3. Now mount a piece of mirror on the door frame such that it is exactly aligned with the unit. Pin configurations of IC UM3561 and transistors 2N5777 and BC547 are shown in Fig. 2.  Fig. 2: Pin configurations of UM3561 and transistors 2N5777 and BC547 Initially, when the door is closed, the infrared (IR) beam transmitted by IR LED1 is reflected (by the mirror) back to phototransistor 2N5777 (T1). The IR beam falling on phototransistor T1 reverse biases npn transistor T2 and IC...

Polygon can be used for various purposes, for example: We can draw large signal areas by using it in any shape. or we can use it to fill the empty pcb area with copper, to make it look more professional. For 1 st purpose make a board in eagle, give name to the signal (as -ve in below fig). Now draw the poly gon (as i mentioned in my previous article) and give it the same name i.e., -ve. The result is like this: You can see the –ve signal and polygon merges together. For 2 nd option, just change the name of polygon (say Vcc) without changing the signal name. After doing this you will find this: Both the signals are separate. So, you can easily find the difference between these two.