Warning lamp arrangements for vehicle battery charging systems
First Claim
1. A warning lamp arrangement for a vehicle battery charging system including an alternator having an armature winding, a resistor network comprising a plurality of resistors, one end of each resistor being connected to a respective output phase of the armature winding and the other end being connected to a common point, and means sensitive to the voltage waveform at said common point for illuminating a warning lamp when the voltage waveforms exceeds its normal amplitude relationship to the battery voltage, said voltage sensitive means comprising a pair of voltage comparators and a pair of voltage reference sources defining said normal amplitude relationship, and each comparator having one input connected to said common point and its other input connected to a respective one of said voltage reference sources.
1 Assignment
0 Petitions
Accused Products
Abstract
A warning lamp arrangement for a vehicle battery charging system comprises three resistors (16, 17, 18) connecting a point (19) to the output terminals of an alternator stator winding (10). The said point (19) is connected to the positive terminal of the battery (12) through a resistor (20) and to its negative terminal through a zener diode (34) and a resistor (35). A pair of comparators (21, 22) having their outputs connected to the base of a Darlington transistor (28, 30) detect if the voltage at the said point (19) is outside a predetermined range. The junction of the zener diode (34) and its as associated resistor (35) is also connected to the base of the Darlington transistor (28, 30). A warning lamp (32) connected in the collector circuit of the Darlington transistor is energized if the alternator does not produce an output or a malfunction occurs in the charging system.
14 Citations
5 Claims
- 1. A warning lamp arrangement for a vehicle battery charging system including an alternator having an armature winding, a resistor network comprising a plurality of resistors, one end of each resistor being connected to a respective output phase of the armature winding and the other end being connected to a common point, and means sensitive to the voltage waveform at said common point for illuminating a warning lamp when the voltage waveforms exceeds its normal amplitude relationship to the battery voltage, said voltage sensitive means comprising a pair of voltage comparators and a pair of voltage reference sources defining said normal amplitude relationship, and each comparator having one input connected to said common point and its other input connected to a respective one of said voltage reference sources.
Specification