Jännitteensäätäjäpiiri

Jännitteensäätäjäpiiri, often translated as voltage regulator circuit, is an electronic circuit designed to maintain a constant output voltage at a desired level, regardless of variations in the input voltage or the load current. These circuits are crucial components in almost all electronic devices that require a stable power supply.

The fundamental principle behind most voltage regulator circuits involves comparing the output voltage to a reference voltage and then adjusting a control element to counteract any deviations. The reference voltage is typically provided by a voltage reference diode, such as a Zener diode, or a more precise voltage reference IC.

There are two primary types of voltage regulators: linear regulators and switching regulators. Linear regulators, like the ubiquitous LM78xx series, operate by dissipating excess energy as heat. They are simple, provide low noise output, but can be inefficient, especially when the difference between input and output voltage is large. Switching regulators, on the other hand, are more efficient. They achieve regulation by rapidly switching a power transistor on and off, storing energy in inductors and capacitors, and releasing it to the load at the desired voltage. While more complex and potentially noisier, their high efficiency makes them suitable for battery-powered devices and high-power applications.

The choice of regulator circuit depends on factors such as required efficiency, acceptable noise levels, cost, and the range of input voltage and load current variations expected. Common applications include power supplies for microcontrollers, sensors, audio equipment, and digital logic circuits, ensuring their reliable operation by providing a stable and predictable voltage.