Patent ID: 6465996
Filing Date: 2002-10-15
Classification: H02J

Abstract:
A constant voltage circuit fed with a first voltage through a positive power conductor and a ground conductor for supplying a second voltage to a load, the constant voltage circuit including:an output transistor having a control electrode and having first and second channel electrodes constituting a primary output path to said load by having said first channel electrode connected with said ground conductor and said second channel electrode connected with one end of said load, with another end of said load being connected to said positive power conductor; bias means for providing a bias voltage to said control electrode to turn on said output transistor; an NPN transistor having an emitter connected to said ground conductor and a collector connected to said second channel electrode of said output transistor and said one end of said load; and means, responsive to a detection of a lowering of said first voltage to a predetermined voltage, for driving said NPN transistor to turn on said NPN transistor to provide a secondary output path connected in parallel with said primary output path, thereby minimizing the degree of lowering of said second voltage due to the lowering of said first voltage.