fázisszabályozó

A fázisszabályozó (phase controller or phase angle controller) is a device used in power electronics to regulate the voltage and power delivered to a load by adjusting the point in the AC supply cycle at which the load is connected. It operates by inserting a controlled delay – the phase angle – before the load is engaged. The result is a reduction of the effective voltage seen by the load, allowing for dimming of lamps, speed control of motors, and precise power management in various industrial processes.

The basic principle relies on a triac, silicon controlled rectifier (SCR), or MOSFET gate drive circuit. When the supply voltage reaches a predetermined trigger point, the controller activates the switching device, allowing current to flow for the remaining portion of the half‑cycle. By advancing or delaying this trigger angle, the average voltage supplied to the load is varied. This technique provides smooth power adjustment and is widely used in incandescent lamp dimmers, light‑flooding control, and HVAC motor speed regulation.

In residential and commercial lighting systems, phase angle control offers an inexpensive alternative to DC dimming, though it can introduce harmonic distortion. Advanced circuits employ filtering or active harmonic mitigation to reduce electromagnetic interference. Regulatory standards such as IEC 61734-1 and UL 1446 set limits on the quality and safety of phase control devices.

Historically, the development of phase control began in the 1960s with the advent of solid‑state switching devices. Modern implementations integrate microcontrollers for digitally adjustable phase angles and real‑time monitoring, enhancing performance and allowing integration with building automation systems.

Applications of fázisszabályozó extend beyond lighting; they are used for controlling the speed of three‑phase induction motors, regulating heat in industrial furnaces, and in power factor correction schemes. Despite their ubiquity, careful design is essential to avoid over‑heating, excessive voltage transients, and compliance with safety regulations.