hõõgumisfilter

Hõõgumisfilter, also known as a glow filter or incandescent filter, is a type of electrical filter used in certain electronic circuits. Its primary function is to suppress or reduce high-frequency noise or unwanted signals that can interfere with the proper operation of a device. Unlike conventional filters that might use inductors and capacitors, a hõõgumisfilter relies on the principle of incandescent light emission from a heated element.

The core component of a hõõgumisfilter is a resistive element, often a filament similar to that found in an incandescent light bulb. When current flows through this filament, it heats up and begins to glow, emitting light. The resistance of the filament changes with temperature. At higher frequencies, the rapid fluctuations in the signal cause the filament to heat and cool rapidly, leading to significant changes in its resistance. This dynamic resistance change effectively dampens or filters out the high-frequency components.

Hõõgumisfilters were historically used in applications where simplicity and robustness were prioritized, and where the specific filtering characteristics were suitable. They were particularly useful in older radio or audio equipment. The effectiveness of a hõõgumisfilter is dependent on factors such as the filament material, its mass, and the operating temperature. While less common in modern electronics due to the availability of more precise and compact active and passive filtering components, the concept of using thermal effects for filtering remains an interesting aspect of electronic design history.