초록 ▼

An improved Up-and-Down Chopper Circuit is provided which is useful for voltage regulation in a bi-directional DC power system. In the down mode, power is switched from a DC power source to a lower voltage energy storing load while in the up mode stored energy in the load is transferred to the highe

An improved Up-and-Down Chopper Circuit is provided which is useful for voltage regulation in a bi-directional DC power system. In the down mode, power is switched from a DC power source to a lower voltage energy storing load while in the up mode stored energy in the load is transferred to the higher voltage source. The system uses Darlington transistor switches in a conventional connection. The improvement relates to circuit additions to eliminate the effects of inter-electrode capacitance inherent with this Darlington transistor switching arrangement.

대표청구항 ▼

In a Darlington transistor type “up-and-down”chopper for regulating a DC voltage from a source supplying energy to an energy storing load in a “down”operating mode and alternately transferring energy stored in said load to said source in an “up”operating mode including first and second Darlington tr

In a Darlington transistor type “up-and-down”chopper for regulating a DC voltage from a source supplying energy to an energy storing load in a “down”operating mode and alternately transferring energy stored in said load to said source in an “up”operating mode including first and second Darlington transistors connected in a series-shunt relationship, respectively, between said source and said load, an inductor connected in immediate series with said load for smoothing the chopped current flowing through said load, a base drive logic circuit means for supplying base drive signals to the base electrodes of said first and second transistors to switch said first transistor “on”and “off”at a selected rate when said chopper is operating in said down mode and switching said second transistor “on”and “off”at a selected rate when said chopper is operating in said up mode, a first free-wheeling diode connected in parallel with the series connected inductor and load for maintaining conduction of current through said load in the down mode during the time said first transistor is switched “off”and a second free-wheeling diode connected between said source and said series connected inductor and load for conducting current from said load to said source in said up mode during the time said second transistor is switched “off”, the improvement comprising: a first charging circuit means for applying the DC source voltage between the collector and emitter electrodes of said second transistor to charge the inter-electrode capacitance of said second transistor to prevent conduction through said second transistor when said first transistor is turned “on”, and a second charging circuit means for applying the DC source voltage between the collector and emitter electrodes of said first transistor to charge the inter-electrode capacitance of said first transistor to prevent conduction through said first transistor when said second transistor is turned “on”.