Lineaarijännite

Lineaarijännite is a Finnish term that translates to linear voltage or linear power supply in English. It refers to a type of direct current (DC) power supply that uses a transformer, rectifier, and a linear regulator to produce a stable DC output voltage.

The fundamental principle behind a linear power supply is the regulation of voltage through a dissipative process. Typically, a transformer steps down the incoming AC mains voltage. This AC voltage is then rectified into a pulsating DC voltage. A filter capacitor smooths this pulsating DC to a less variable, but still potentially fluctuating, DC voltage. The final stage is the linear regulator, which actively adjusts its internal resistance to maintain a constant output voltage, even if the input voltage or the load current changes. This regulation is achieved by dissipating excess voltage as heat.

Linear power supplies are known for their simplicity, low output noise, and fast transient response, making them suitable for sensitive electronic applications like audio equipment and sensitive measurement devices. However, their main disadvantage is their inefficiency, especially when the difference between the input and output voltages is large. This inefficiency leads to significant heat generation, often requiring substantial heatsinks for the regulator. Compared to switching power supplies, linear power supplies are generally bulkier and heavier for equivalent power output.