Leroy A Baker

US Patent:

39683338, Jul 6, 1976

Filed:

Sep 18, 1973

Appl. No.:

5/398448

Inventors:

Frank L. Simokat - Euless TX
LeRoy S. Baker - Grapevine TX

Assignee:

Superior Continental Corporation - Hickory NC

International Classification:

H04H 108
H04M 100

US Classification:

179 16A

Abstract:

A telephone transmission system in which a telephone transmission line connects a central office d. c. power source to a battery charging control circuit to apply an input voltage to the control circuit, in which a battery charger connects a rechargeable battery to said control circuit to draw battery charging current from the transmission line under the control of the control circuit, in which the control circuit is rendered effective by a lowering of the input voltage to at least a predetermined value to effectively disconnect the battery charger and the battery from the transmission line for a period that exceeds the interval in which the input voltage is lowered.