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US 4,068,216 AGranted
Bulb outage warning system
AssigneeStewart-Warner Corporation
InventorsFrans Brouwer, Francis E. Ferrari
Life of this patent
Estimating the term…
Abstract
A warning system for detecting a burned out or defective bulb for a motor vehicle is disclosed. A transmitting circuit is connected to detect current flow through the bulb to be monitored. Failure of the bulb to draw current causes the transmitting circuit to produce a series of small voltage pulses on the battery line. These pulses are detected by a receiving circuit which causes an outage indicator light to be illuminated.
Claims5
A receiving circuit for producing an output in response to a signal pulse train imposed on a voltage supply line comprising:
- a. means for detecting the presence of pulses on said supply line,
- b. indicating means,
- c. control means responsive to said pulses for initiating operation of said indicating means, and
- d. digital filter means for discriminating between no pulses, random pulses, and said train of pulses for inhibiting said control means when no pulses or random pulses are detected.
1 more element
Dependencies are inferred from the claim text.