System for remotely checking equipment
First Claim
1. A system for remotely checking the operable condition of at least one piece of electrical equipment, the system comprising:
- a switch means responsive to the operable condition of said one piece of electrical equipment;
an oscillator means for generating a distinctive low frequency electrical signal, its output being connected to said switch means;
a switching means in series with said switch means for selectively coupling and output signal from said oscillator means directly to a telephone line, said switching means including a controlled rectifier having a cathode, an anode and a control electrode, said anode and said control electrode being coupled respectively to the cathode and anode of a first diode, which is a Zener diode, said Zener diode having its anode connected, via a resistance, in series with an energizing coil of a relay forming at least part of said switching means;
means responsive to a call signal on the telephone line for effecting closing of said switching means upon arrival of a call signal; and
timing means for effecting opening of said switching means upon expiration of a given period of time subsequent to receipt of a call signal;
whereby a user may place a call signal on the telephone line and determine if the oscillator means is supplying a distinctive signal directly to the telephone line as an indication of the operable condition of the piece of equipment.
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Accused Products
Abstract
A system for checking the operable conditions of one or more pieces of electrical equipment from a remote position includes an individual oscillator associated with each of the pieces of equipment to be checked. Switches which are responsive to the condition of the equipment are provided to connect the individual oscillators to a switching means. The switching means is operatively responsive to a call signal from a telephone line for effecting the coupling of signals from the oscillators to a telephone line. A timing circuit is provided to disconnect the oscillators from the telephone line after a given period of time expires. Each oscillator has a different distinctive output signal characteristic.
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Citations
8 Claims
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1. A system for remotely checking the operable condition of at least one piece of electrical equipment, the system comprising:
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a switch means responsive to the operable condition of said one piece of electrical equipment; an oscillator means for generating a distinctive low frequency electrical signal, its output being connected to said switch means; a switching means in series with said switch means for selectively coupling and output signal from said oscillator means directly to a telephone line, said switching means including a controlled rectifier having a cathode, an anode and a control electrode, said anode and said control electrode being coupled respectively to the cathode and anode of a first diode, which is a Zener diode, said Zener diode having its anode connected, via a resistance, in series with an energizing coil of a relay forming at least part of said switching means; means responsive to a call signal on the telephone line for effecting closing of said switching means upon arrival of a call signal; and timing means for effecting opening of said switching means upon expiration of a given period of time subsequent to receipt of a call signal; whereby a user may place a call signal on the telephone line and determine if the oscillator means is supplying a distinctive signal directly to the telephone line as an indication of the operable condition of the piece of equipment. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification