摘要 |
The collector-to-emitter voltage (VCE) of a transistor switch and its base drive are designed to have maximum specified values when the transistor switch conducts the highest specified load current. The base drive to the transistor switch is reduced when the load current is reduced, or when the beta of the transistor increases or is greater than a minimum specified value. The base drive to the transistor switch is regulated by sensing the VCE of the transistor switch and producing a control current which decreases with decreasing VCE and increases with increasing VCE. The control current is then used to supply a regulated base current to the transistor switch while maintaining the VCE of the transistor below, the maximum specified value, for values of load current below the maximum specified level.
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