Zero Volt Switching (ZVS) Zero-volt switching (ZVS) refers to a switching method in which an electronic switch—usually a MOSFET or relay—is only activated at the moment when the voltage of the load to be switched is zero volts. This makes switching on and off particularly gentle and efficient. How ZVS works Phase monitoring The electronics continuously measure the AC voltage and detect the zero crossing. Switching process at zero crossing The switch is activated or deactivated exactly when the instantaneous voltage is at 0 V. Reduced electrical load Since the current and voltage are minimal at the moment of switching, there are hardly any overvoltage peaks or arcing. Benefits of ZVS Benefit Technical Effect Advantage in operation Lower inrush current Components are not subjected to high peak currents when switched on. Protects sensitive AV or IT equipment and prevents fuses from tripping. Minimized electromagnetic interference Reduced voltage spikes and harmonic harmonics. More stable operation of sensitive AV setups with less signal interference. Longer service life of relays and loads Less contact wear and thermal stress. More sustainable usage of integrated relays and connected hardware. Smooth, controlled power-up Uniform current consumption. Ideal for devices with transformers and switching power supplies. Efficient energy use Minimization of power loss at the moment of switching. Improved overall energy balance in the rack or installation. Particularly with intelligent power distribution units (PDUs), consumers are often switched automatically, e.g. via: Remote reboots Programmed schedules Sensor values Threshold events This results in numerous switching operations during daily operation. Zero-volt switching prevents these switching operations from causing electronic stress, device malfunctions, or premature wear. Especially in professional environments—AV installations, studios, IT racks, digital signage, broadcast, industrial automation—ZVS increases the operational reliability of an entire infrastructure. GUDE uses for most PDUs precise zero-crossing detection units to ensure particularly gentle and reliable switching operations – ideal for professional AV, IT, and industrial environments. How GUDE smart PDUs work Continuous zero crossing detection The PDU continuously measures the mains voltage and detects every zero crossing with high temporal accuracy. Switching at the optimal moment The relay is only activated when the current voltage is 0 V – i.e., when the technically most favorable point for switching has been reached. Temperature-compensated detection GUDE uses measuring modules for most devices that take temperature-related deviations into account to ensure precise zero crossing detection even under changing environmental conditions. Depending on the device model, the electronics detect the zero crossing with ±0.8 ms or ±1.0 ms temperature-compensated accuracy. All terms in Expert Know-how