COMBITRON Rectifiers

KEB COMBITRON Rectifiers are compact AC-to-DC conversion modules designed to power electromagnetic clutches and spring-applied brakes by turning 50/60 Hz input into the correct DC coil voltage. Within the line, Type 91 units are sized for motor terminal-box installation and are offered as full-wave or half-wave versions to suit the available AC supply. They feature built-in suppression and allow either AC-side or DC-side switching. The COMBITRON 98 "Powerbox" rectifiers add rapid switching with controlled overexcitation to sharpen engagement and release, available for 24 VDC supply or for 180-300 VAC supply. The 98 series defines application limits including maximum permissible coil-cable length, specified overexcitation pulse durations, and current ratings that must be derated for higher temperatures and altitude. Switching behavior is addressed clearly: AC-side interruption lengthens release delay, while DC-side switching accelerates release by dissipating stored magnetic energy; for higher DC-side switching rates, a parallel varistor is recommended.