Light Detecting Circuit

The schematic attatched above shows the circuit that has been made. This project uses many components to create a circuit that lights up an LED bulb when the LDR detects darkness. This works because we use a variable resistor to change the resistance for the specific surroundings. The Final circuit is then housed in a custom made 3d printed box.

Wires

NPN 2N2222 Transistor

1000 OHM Resistor

370 OHM Resistor

Led(white)

100K Potentiometer

Perf Board

Power Supply or Batter pack (6V)

In this project, a person should take notice of the different safety risks and know how to avoid them. Immediately, the risk of burns is the greatest when working with a soldering iron, which can be very hot at temperatures near 450 degrees celcius. It is vital to use a soldering stand and to handle the tool appropriately. Additionally, wearing safety glasses at all times is essential, as solder and vapours can irritate the respiratory system, and the splashing of hot solder can harm the eyes. It is also necessary to use a fume extractor or to work in a well-ventilated area. Besides soldering, good electrical practice should be followed, such as always removing the power supply before making any modifications to the circuit, as short circuits can cause the system to overheat. Lastly, watch out for general workshop dangers such as sharp component leads and, in the use of a 3D printer, the moving parts as well as the hot nozzle and heated bed. By adhering to these guidelines, the process can be made safe and pleasurable. Lastly if you use a power supply monitor that voltage going into the circuit, if the voltage is too high you can fry the LED and damage other components on the circuit.

The safest, cheapest, and most instructive form of trial and error is Tinkercad, so the very first thing you should do is remotely create your circuit in a simulator like Tinkercad. As the name suggests, this makes it possible to build and test virtually, thereby eliminating any possibility of component damage or reliance on physical shock. The learning curve is therefore open and unhindered, as any and all errors bear no consequence. Since the entire set of components is imaginary, there is no need to purchase or source any actual parts, thus encouraging learning and repeated attempts with no financial downfall. The simulation shows how the virtual circuit operates in real time, making it possible to use a virtual multimeter to take voltage and current measurements instantaneously. It also shows the effect of changing a component on the entire circuit. Such direct feedback makes it a lot simpler to grasp the concept of the circuit as well as to troubleshoot the design before implementing it physically.

Step 1: Breadboard Prototyping

After simulation, the next step is to prototype your circuit on a breadboard. The main purpose for a breadboard is its ease of use and its solderless design. A breadboard is a composite board that is reusable and has a matrix of holes internally interconnected with metal strips. To form connections you merely push the leads of components and jumper wires in the holes. The biggest advantage is that it is very simple to test out your designs and change components and their values easily to iron out any design issues. It is the best way to ensure that your circuit functions the way you desire.

Step 2: Transfer Design to Perfboard

After you have verified that your circuit functions properly on the breadboard, you then transfer the design to a perfboard. A perfboard is a sheet of material with a grid of pre-drilled holes, Each hole has a small copper pad on the underside. Unlike a breadboard, the pads on a perfboard are not connected. You must create the connections

After completing your circuit and testing it, the next procedure to carry out build a 3D case for your circuit, which is done through CAD (Computer-Aided Design) software like Fusion 360 or Shapr3D. This step is compulsory in order to move on with your project, as it prepares it for the next level beyond the initial stages, which is the finished product that works.

A case adds a necessary layer of protection to the circuit. A circuit crafted on a breadboard or a perf board is very prone to physical and dust damage, as well as to moisture and short circuiting. A case designed specifically for the circuit helps to protect the components from damages and helps keep the circuit functioning optimally for a long period.

With Shapr3D or Fusion 360, you can craft a case that fits your project superbly. The LDR and any other components such as an LED or a power switch can be designed with cutouts specifically meant for them. This guarantees that the components fit neatly and sorted while looking professional. You can incorporate features like mounting holes, screw bosses, and snap-fit joints to make the assembly of the case simple yet secure.

You may need a couple of different designs before you get the correct fit, for me it was on my 3rd design that I got it right but for my friend he took 7 tries before getting it right.With a case printed using a 3D printer, your project changes from a simple circuit to a polished and well-thought-out device.

The last task involves merging all the components and the calibration work. This means you have to place the soldered perfboard circuit inside the custom 3D-printed casing and ensure that the LDR and any other components inside are properly placed inside their cutouts. The most important task to do last is to adjust the variable resistor. Here, you get to adjust your circuit's sensitivity to the variable resistor and tune it to the perfect setting. The variable resistor is turned to change the voltage and thus the level of light at which the circuit will trigger, ensuring the light comes on at its brightest when it's dark, and turning off the light when it's light. The rest of the device depends completely on this tuning for the successful functioning of the overall device.