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US 4,234,967 AGranted
Optical signal transmitter
AssigneeMinnesota Mining and Manufacturing Company
InventorJohn P. Henschel
Life of this patent
Estimating the term…
Abstract
An optical signal transmitter for use by priority vehicles for remotely controlling traffic signals, including a light source which is flashed at a controlled repetition rate to transmit an optical signal to a receiver located at the traffic intersection. Circuitry associated with the light source includes a comparator network for disabling an electrical energy supply in the event of certain predetermined operating conditions.
Claims8
An optical signal transmitter having,
- a light source for converting stored electrical energy into light energy in response to a trigger signal,
- trigger means for providing a trigger repetition rate signal having a controlled repetition rate,
- electrical energy storage means, and
- electrical energy supply means for supplying electrical energy to said electrical energy storage means;
- wherein the improvement comprises
- means for disabling said electrical energy supply means in response to a disable signal,
- means for generating a reference signal,
- means for generating an input signal indicative of a measured operating condition, and
- means for comparing said reference signal with said input signal to generate said disable signal for controlling said electrical energy supply means such that said light source is operable only under predetermined operating conditions.
6 more elements
An optical signal transmitter having,
- a light source for converting stored electrical energy into light energy in response to a trigger signal,
- trigger means for providing a trigger repetition rate signal having a controlled repetition rate,
- electrical energy storage means, and
- electrical energy supply means for supplying electrical energy to said electrical energy storage means;
- wherein the improvement comprises
- means for disabling said electrical energy supply means in response to a disable signal,
- means for generating an input signal responsive to said trigger repetition rate signal to disable said electrical energy supply means when a trigger signal is generated,
- means for comparing said reference signal with said input signal to generate said disable signal for controlling said electrical energy supply means such that said light source is operable only under predetermined operating conditions.
5 more elements
An optical signal transmitter, comprising:
- a gas discharge light source for converting stored electrical energy into light energy in response to a trigger signal;
- a trigger repetition rate generator coupled to said gas discharge light source for providing a trigger signal having a controlled repetition rate;
- a capacitor coupled to said gas discharge light source to provide electrical energy storage;
- an electrical energy supply coupled to said capacitor;
- a disable circuit coupled to said electrical energy supply responsive to a disable signal;
- a regulated power supply producing a reference signal;
- and
- a comparator coupled to said trigger repetition rate generator comparing said reference signal to an input signal indicative of a measured operating condition to generate said disable signal based upon said comparison;
- whereby said gas discharge light source is operable only under predetermined operating conditions.
6 more elements
Dependencies are inferred from the claim text.