ClassX Video Lessons Youtube Channel The Engineering Mindset 5V Regulator design tutorial – How it works, how to design PCB altium
When electronic components receive too much voltage, they can burn out or even explode. To prevent this, a voltage regulator is essential. This article will guide you through understanding how a voltage regulator works, designing one, and transforming it into a functional printed circuit board (PCB) that can serve as a power supply and even charge a phone.
A voltage regulator’s primary function is to maintain a constant output voltage, even when the input voltage fluctuates. This consistency is crucial because electronic components are designed to handle only specific voltage levels. For instance, connecting an LED directly to a 9-volt battery can destroy it due to the excessive voltage.
To protect components like LEDs, resistors are often used to limit current. However, as voltage increases, resistors can overheat, leading to component failure. Therefore, a stable 5-volt DC supply with sufficient current is necessary, especially when connecting to various voltage sources like 9-volt or 12-volt batteries.
The LM7805 is an integrated circuit that provides a steady 5-volt DC output and can handle up to 1.5 amps of current. It is compatible with any DC supply voltage ranging from 7 to 35 volts, making it versatile for different applications.
The LM7805 has three pins: the first pin is for the unregulated voltage input, the second is the ground pin, and the third is the regulated 5-volt output. To optimize performance, manufacturers recommend using capacitors on both the input and output sides.
Capacitors play a crucial role in smoothing out voltage fluctuations and filtering noise. For instance, a 0.22 microfarad electrolytic capacitor can be used on the input side to manage interruptions and low-frequency distortions. Additionally, a 0.1 microfarad ceramic capacitor acts as a bypass capacitor to filter high-frequency noise.
On the output side, a combination of a 0.1 microfarad bypass capacitor and a 10 microfarad electrolytic capacitor ensures a clean and stable output voltage for connected circuits.
To protect the circuit from incorrect power supply connections, a protection diode is added on the input side. This diode allows current to flow in one direction, preventing damage if the power supply is connected in reverse. Options include using a rectifier diode or a Schottky diode, with the latter having a lower voltage drop.
Before creating a PCB, it’s advisable to test the circuit on a breadboard. This allows you to verify the functionality of the components and connections. Once confirmed, you can proceed to design the PCB using Altium Designer, a powerful tool for creating electronic designs.
To begin, open Altium Designer and create a new project. Add a schematic and PCB layout, then save both. Use the components tool to insert necessary components like capacitors, the LM7805 regulator, and the protection diode.
Connect the components using the wire tool, annotate the schematic, and validate the design. After validation, import changes to the PCB layout, arrange the components, and ensure correct positioning. Check the design rules and make adjustments as needed.
Once the design is validated, generate a PDF and prepare the Gerber files for fabrication. JLCPCB is recommended for ordering the PCB due to their excellent service and value. Upload the Gerber files, customize the order, and proceed to checkout.
After receiving the PCB, assemble it by placing and soldering the components. Test the circuit by connecting it to a 9-volt battery. A multimeter should read 5 volts on the output, confirming the circuit’s functionality and the diode’s protective role.
Finally, connect a USB port to the circuit to charge a phone, verifying that the design works as intended. This project not only provides a practical power supply solution but also enhances your understanding of electronics and PCB design.
For further learning in electrical and electronics engineering, explore additional resources and tutorials available online. Stay connected with the community through social media and educational websites for continuous learning and inspiration.
Set up the LM7805 voltage regulator circuit on a breadboard. Use various input voltages and measure the output to observe the regulation process. This will help you understand the practical application of voltage regulation and the importance of capacitors and diodes in the circuit.
Participate in a workshop where you will use Altium Designer to create a schematic and PCB layout for the voltage regulator circuit. This activity will enhance your skills in electronic design automation and familiarize you with industry-standard tools.
Use simulation software to model the voltage regulator circuit. Analyze the effects of different capacitor values and diode types on the circuit’s performance. This will deepen your understanding of component selection and circuit stability.
Once your PCB is fabricated, assemble the components and test the circuit. Use a multimeter to verify the output voltage and ensure the circuit functions correctly. This hands-on experience will solidify your knowledge of PCB assembly and testing procedures.
Engage in a group discussion to share your experiences and challenges faced during the project. Prepare a presentation on your findings and the importance of voltage regulation in electronic circuits. This activity will improve your communication skills and reinforce your learning.
Here’s a sanitized version of the provided YouTube transcript:
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This is what happens when we supply too much voltage to our electronic components: the components can burn out or even explode. To prevent this, we need a voltage regulator, and I’m going to show you how it works, how to design one, and how to turn it into a fully functional printed circuit board to use as a power supply and even charge a phone with it. You can download a copy of my circuit board; links are in the video description below.
The purpose of a voltage regulator is to maintain a constant output voltage even when the input voltage changes. This is important because electronic components are rated to handle only a certain voltage. For example, if we connect an LED to a 9-volt battery, it will be destroyed instantly. This is due to the thin wire inside the LED, which can’t handle the excess voltage.
To protect the LED, we need a resistor to reduce the current. In this example, I’m using a 10-ohm resistor connected to a variable DC power supply. When we apply a small voltage, the LED works fine, but as we increase the voltage, the resistor can overheat, and the LED will be destroyed.
To ensure a constant output voltage, we need to maintain a stable 5-volt DC supply with enough current to charge a simple phone. We want to connect this to multiple voltage sources, such as 9-volt or 12-volt batteries. For this, we will use an integrated circuit component. After some research, I found the LM7805, which can maintain a constant 5-volt DC output and handle up to 1.5 amps of current. This component can be connected to any DC supply voltage between 7 and 35 volts, making it suitable for our needs.
The LM7805 has three pins: pin 1 is for the unregulated voltage input, pin 2 is the ground pin, and pin 3 is the regulated 5-volt output. The manufacturer recommends using capacitors on both the input and output. The input capacitor is necessary if the regulator is far from the power supply filter. We will use a 0.22 microfarad electrolytic capacitor to help smooth out interruptions and low-frequency distortions.
In a simple example, you can see that the LED turns off instantly when the power is interrupted. However, if we place a capacitor in parallel with the LED, it will remain on because the capacitor discharges and powers the LED, making it less affected by interruptions.
We will also add a bypass capacitor on the input side, which is a small ceramic capacitor typically rated at 0.1 microfarads. This capacitor filters out noise and high-frequency distortions from the power supply. We will add another 0.1 microfarad bypass capacitor on the output side, along with a 10 microfarad electrolytic capacitor. These components will help ensure a clean output for our connected circuit.
Additionally, we will add a protection diode on the input side to safeguard the circuit if the power supply is connected incorrectly. For demonstration, if I connect an incandescent lamp to a power supply, it will illuminate. If I reverse the leads, it will still illuminate. However, if I place a diode on the positive lead, it will illuminate in one direction but block the current when reversed, keeping the lamp off.
We can use either a rectifier diode or a Schottky diode. The LED connected to the rectifier diode is not as bright due to its larger voltage drop compared to the Schottky diode, which has a lower voltage drop.
Next, we can lay out all these components on a breadboard to test the circuit. Once we confirm it works, we can turn this into a printed circuit board (PCB). For this tutorial, we will use Altium Designer, which has kindly sponsored this video. All viewers can get a free trial of this software using the link in the video description.
To create the PCB, open Altium Designer, create a new project, and add a schematic and PCB layout. After saving both, we can add the components using the components tool or an add-on for easier access. We will find and insert the required components, including capacitors, the regulator, and the protection diode.
Once all components are placed, we will connect them using the wire tool, ensuring to annotate the schematic and validate the design. After validating, we will import changes to the PCB layout, arrange the components, and ensure everything is correctly positioned.
Next, we will check the design rules and make any necessary adjustments. Once everything is validated, we can generate a PDF of our design and prepare the Gerber files for fabrication.
I recommend using JLCPCB for ordering the PCB, as they offer excellent value. After uploading the Gerber files and customizing the order, we can proceed to checkout.
Once the circuit board arrives, we can begin building it by laying out the components and soldering them in place. After completing the assembly, we will test the circuit board by connecting it to a 9-volt battery. The multimeter should read 5 volts on the output, confirming that the diode is protecting the circuit.
Finally, we can connect a USB port to charge a phone, verifying that the circuit works as intended.
That’s it for this video! To continue learning about electrical and electronics engineering, check out one of the videos on screen now. Don’t forget to follow us on social media and visit theengineeringmindset.com for more resources.
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This version removes any informal language and maintains a professional tone while retaining the essential information.
Voltage – The electrical potential difference between two points in a circuit, measured in volts. – The voltage across the resistor was measured to ensure it was within the safe operating range.
Regulator – A device used to maintain a constant voltage level in an electrical circuit. – The voltage regulator in the power supply ensured that the output remained stable despite fluctuations in input.
PCB – Printed Circuit Board, a board used for mounting electronic components and connecting them through conductive pathways. – The engineer designed a compact PCB to fit all the necessary components for the new gadget.
Capacitors – Electronic components that store and release electrical energy in a circuit. – The capacitors were used to smooth out the voltage fluctuations in the power supply circuit.
Current – The flow of electric charge in a circuit, measured in amperes. – The current flowing through the circuit was too high, causing the fuse to blow.
Diode – A semiconductor device that allows current to flow in one direction only. – The diode was used to prevent reverse current from damaging the circuit components.
Circuit – A closed loop through which an electric current flows or may flow. – The students built a simple circuit to demonstrate the principles of Ohm’s Law.
Breadboard – A construction base used for prototyping electronics, allowing components to be easily inserted and removed. – The team used a breadboard to test their circuit design before finalizing the PCB layout.
Design – The process of planning and creating a system or component to meet desired needs and specifications. – The design of the new amplifier circuit focused on minimizing noise and maximizing efficiency.
Electronics – The branch of physics and engineering concerned with the behavior and movement of electrons in semiconductors, conductors, and vacuum. – The course in electronics covered topics such as semiconductor devices and digital circuits.
