Power supplies are at the heart of most electronics projects, and ensuring they run smoothly is essential for prototypers and engineers. In switched-mode power supplies (SMPS), current sensing is crucial to monitor and control the power being delivered to the load. Without it, systems can overheat or become unstable. But how can you manage this?

The Problem :

SMPS typically rely on feedback to regulate voltage and current. A common issue occurs when current sensing is not implemented correctly, causing inaccurate readings, overheating, or even damage to components.

The Solution :

To address this, engineers often use shunt resistors, Hall effect sensors, or current transformers. A simple solution is using a low-value shunt resistor in series with the load, allowing you to measure the voltage drop, which correlates to the current. If you’re a hobbyist, this method is easy to implement and widely available.

Example :

Imagine you’re building a power supply for your 12V LED strip. Without current sensing, you risk supplying too much or too little power. By adding a shunt resistor, you can easily monitor and control the current, ensuring the LEDs function optimally without risk of damage.

Sample Calculation :

Let’s say your power supply is set to deliver 12V, and you’ve chosen a 0.1-ohm shunt resistor.

If your circuit draws 1A of current, the voltage drop across the resistor will be:

V=I×R=1A×0.1Ω=0.1V

This small voltage drop can be measured to monitor current.

Product Suggestion :

For your current sensing needs, consider the precision resistors or Hall effect sensors available at SmartXProKits.

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