Using a PCB as a weighing scale

TL;DR

A detailed walkthrough of a strain gauge project using load cells and PCB design.

Transcript

foreign in this video I'm going to show you another project which I recently finished you can see one of the results here and this is one of its let's say competitor so I was thinking about this project for a while and I mainly made this for let's say prototyping and learning purposes but this can be a very nice let's say jumping board for other pr... Read More

Key Insights

• 🏋️ Strain gauges can effectively measure weight and stress when incorporated into a properly designed electronic system, utilizing principles from basic circuits.
• 🦾 The Wheatstone bridge circuit is pivotal in converting mechanical strain into an electrical signal that can be amplified for measurement.
• 😘 The challenges associated with low conductivity materials in PCB design can introduce complications in accurately measuring resistance changes.
• 🖐️ Operational amplifiers play a critical role in enhancing the sensitivity and effectiveness of strain gauge circuits by amplifying tiny voltage changes.
• 🏑 The experimental setup highlighted in the video showcases potential applications for various electronics and prototyping projects in the field of measurement technologies.
• 🕳️ A combination of through-hole and SMD components can accommodate different skill levels and tool availability, expanding the accessibility of electronic projects.
• 👻 Custom PCBs can provide unique solutions for specific electronic applications, allowing for tailored designs capable of achieving desired functionality.

Questions & Answers

Q: What is the primary purpose of the strain gauge project presented in the video?

The primary purpose of the strain gauge project is to serve as a prototyping tool for learning and a proof of concept for future applications. The project showcases the integration of load cells and PCB design for weight measurement, allowing the creator to explore electronic concepts and enhance their skill set.

Q: How does the Wheatstone bridge function in this strain gauge system?

The Wheatstone bridge is a circuit used to measure resistance changes, which is crucial in strain gauge applications. In this project, the strain gauge's resistance changes due to bending, leading to an imbalance in the Wheatstone bridge. This imbalance translates into a measurable voltage change, which is then amplified by operational amplifiers in the circuit.

Q: What challenges did the creator face during the project, and how were they addressed?

One significant challenge was the very low resistance of the pure copper trace used in the PCB, which resulted in minuscule changes in resistance due to bending. This made it difficult to detect meaningful signals without adequate amplification. To address this, the creator implemented a strain gauge and designed the circuit with operational amplifiers to achieve better signal amplification and overall functionality.

Q: What role does the PCB Bank play in this project?

PCB Bank, the sponsor of the video, provides manufacturing and assembly services for printed circuit boards. The creator utilized their PCBs for the strain gauge project, which not only facilitated the design and testing process but also served as a platform for engaging the audience in a PCB design contest, promoting creativity among viewers.

Summary & Key Takeaways

• The video presents a unique strain gauge project designed for prototyping and learning, showcasing a custom PCB for weight measurement.

• The author explores the principles of Wheatstone bridges and operational amplifiers to amplify signals from the strain gauge, addressing challenges encountered during the design process.

• A demonstration highlights the circuit's functionality with various weights, revealing potential for future projects, including advancements in circuit design and component selection.