Patent ID: 6166547
Filing Date: 2000-12-26
Classification: G01R

Abstract:
A loss of battery detector for use on a line card, the line card having a positive voltage operational power feed, a negative voltage battery feed, and a connection to ground, said loss of battery detector comprising:a first resistor connected at one end to the positive voltage operational power feed;a capacitor connected at one end to the positive voltage operational power feed;the other end of said first resister and the other end of said capacitor connected to the negative battery voltage feed;a second resistor having one end connected to said other ends of said first resister and said capacitor;a third resistor connected at one end to the positive voltage operational power feed;an NPN transistor having it's base connected to the other end of said second resistor, it's emitter connected to said ground connection, and it's collector connected to the other end of said third resistor, said positive voltage operational power feed having sufficient voltage to cause said transistor to saturate; anda signal out lead connected to said collector of said transistor.