KEB COMBITRON Rectifiers are compact AC-to-DC modules for supplying electromagnetic clutches and spring-applied brakes, converting 50/60 Hz input power to the required DC coil voltage.
The family includes Type 91 units sized for motor terminal-box mounting, offered as full-wave or half-wave versions to match the available AC supply, with internal suppression and support for either AC-side or DC-side switching. COMBITRON 98 “Powerbox” rectifiers add rapid-switching with overexcitation to improve engagement and release behavior, offered in versions for 24 VDC supply and for 180–300 VAC supply. The 98 series specifies application limits such as maximum coil-cable length, defined overexcitation pulse times, and current ratings with derating for temperature and altitude. Switching behavior is addressed directly: AC-side switching increases release delay, while DC-side switching speeds release by dissipating stored magnetic energy, with a parallel varistor recommended when higher DC-side switching rates are required.
