What is Power Supply
A power supply is a device that converts unregulated DC voltage to a regulated DC voltage. Specifically, in the context of linear LED power supplies, a power supply is an LED driver that utilizes a linear regulator to regulate the output voltage.
A linear regulator, which is a type of power supply, operates in the linear region of a pass element to regulate the output voltage. It consists of various components, including an internal reference voltage, an error amplifier, a feedback voltage divider, a pass transistor, and an output capacitor.
The internal reference voltage serves as a reference point for the regulator, allowing it to compare the desired output voltage with the actual output voltage. The error amplifier monitors the difference between the reference voltage and the feedback voltage, obtained from the output of the regulator. Based on this difference, the error amplifier controls the power switch (pass transistor) to adjust the output voltage and maintain it at the desired value.
To continuously monitor and adjust the output voltage, the regulator utilizes a feedback voltage divider, which provides a portion of the output voltage to the error amplifier for comparison. Additionally, an output capacitor is often included in the power supply circuit to filter out any noise or ripple in the output voltage, ensuring a stable and clean power supply for the LED lighting system.