KEY DEVICE (VERSIONS) Russian patent published in 2009 - IPC H03F3/217 

FIELD: electricity.

SUBSTANCE: according to the first version, key device comprises paraphase signal generator (PSG), preliminary amplifier (PA), transformer (T), key amplifier (KA) and output resonant filter (RF), additionally enabling circuit is introduced, connected between outlets of PSG and inlets of PA, and also the first and second diodes connected serially between busbars of service power supply, besides primary winding of transformer is connected to capacitor of input RF, and medium point of throttle and capacitor of inlet RF is connected to medium point of the first and second diodes. Under conditions of higher working frequencies, in compliance with the second version of invention, the following components are additionally introduced - enabling circuit, four diodes, the second PA and the second inlet RF, besides enabling circuit is connected between outlets of PSG and primary winding of transformer, secondary windings of which are connected accordingly to inlets of the first and second preliminary amplifiers, and outlets of the first and second inlet resonant filters are connected to the first and second inlets of key power amplifier control, the first and second diodes are connected serially between the first busbars of service power supply, and medium point of the first throttle and the first capacitor of the first inlet resonant filter is connected to medium point of the first and second diode accordingly, and the third and fourth diodes are connected similarly between the second busbars of service power supply, and medium point of the second throttle and second capacitor of the second inlet resonant filter.

EFFECT: provision of rated amplitude of pulse signals of key elements control with preservation of soft trajectory of switchover in wide band of working frequencies with reduction of energy losses in preliminary amplifiers and formation of quasi-resonant trajectories of outlet currents and voltages variation in key amplifier, therefore provides for improved parametres of electromagnet compatibility, expansion of band in case of working frequencies increase by formation of quasi-resonant control signals in each channel of preliminary amplifiers separately in each inlet of key power amplifier.

2 cl, 5 dwg