tasajännitelähde

A tasajännitelähde, or DC voltage source, is an electrical component that provides a constant direct current voltage. This means the polarity of the voltage remains the same over time, unlike an alternating current (AC) source where the polarity reverses periodically. DC voltage sources are fundamental to many electronic circuits and devices.

Common examples of DC voltage sources include batteries, which store chemical energy and convert it into electrical energy. Another prevalent type is a power supply unit (PSU), which typically converts AC mains voltage into a stable DC voltage required by electronic equipment. Solar cells also function as DC voltage sources, generating electricity from sunlight.

The output voltage of a DC source is usually specified in volts. The ability of a DC source to deliver current is characterized by its current rating, often measured in amperes. Ideal DC voltage sources are theoretical constructs that would provide a perfectly constant voltage regardless of the load connected. Real-world DC sources have internal resistances that can cause their output voltage to drop slightly as the current drawn increases. The stability and accuracy of the DC voltage are critical for the proper operation of many sensitive electronic components.