Electrical indicating circuit
AssigneeThorn Emi Automation Limited
InventorDavid L. Neasham
Life of this patent
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Abstract
In some industrial situations a battery charger is used to supply d.c. power to an electrical equipment, and a battery is connected across the output terminals of the charger so that a "back-up" supply is available if the charger should fail. An indicating circuit is used to generate a warning if an open circuit condition arises in the battery charging circuit. The indicating circuit operates by monitoring the output impedance of the battery charger. If the output impedance exceeds a threshold value the indicating circuit generates a warning signal.
Claims4
An electrical indicating circuit suitable for indicating an open circuit condition in a battery charging circuit in which a battery charger is coupled across a battery, the indicating circuit comprising
- first circuit means for generating respective voltages related to the output current and the output voltage from the battery charger,
- second circuit means for generating a ratio signal related to the ratio of the voltages, generated by said first circuit means, and so to the output impedance of the battery charger,
- and third circuit means for comparing said ratio signal with a threshold signal and for generating an indication, indicative of an open circuit condition, in dependence on the comparison.
Dependencies are inferred from the claim text.