Apparatus for drawing and processing electrical power from a communications line
First Claim
1. Apparatus for drawing and processing electrical power from a telephone line, the apparatus comprising:
- a pair of terminals for connection to the telephone line,a signal detector coupled to the terminals;
a DC to DC converter connected to receive power from the terminals and to power the signal detector for detecting the presence of a predetermined activation signal on the telephone line,the converter comprising an oscillator and a transformer with primary and secondary windings,the oscillator having an output connected to a primary winding of the transformer and causing DC level switching thereto such that power transfer from the telephone line to a secondary winding of the transformer occurs, andthe signal detector, on detection of the activation signal, causing an increase in oscillator frequency to cause an increase in the power transferred.
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Accused Products
Abstract
Apparatus powered from a communications line minimizes current drawn from the line by use of a variable power supply having a DC to DC conversion circuit controlled by an oscillator. The output of the DC to DC conversion circuit in a first lower power drawing mode is used to power a tone detection circuit which monitors the line for a wake-up tone. On receipt of an appropriate wake-up tone, the tone detection circuit provides an interrupt signal to a microprocessor which, in response, causes an increase in the oscillator frequency. The increased oscillator frequency then increases power drawn from the line via the DC to DC conversion circuit for operation in a second higher power drawing mode.
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Citations
20 Claims
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1. Apparatus for drawing and processing electrical power from a telephone line, the apparatus comprising:
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a pair of terminals for connection to the telephone line, a signal detector coupled to the terminals; a DC to DC converter connected to receive power from the terminals and to power the signal detector for detecting the presence of a predetermined activation signal on the telephone line, the converter comprising an oscillator and a transformer with primary and secondary windings, the oscillator having an output connected to a primary winding of the transformer and causing DC level switching thereto such that power transfer from the telephone line to a secondary winding of the transformer occurs, and the signal detector, on detection of the activation signal, causing an increase in oscillator frequency to cause an increase in the power transferred. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A telephone line powered processor comprising:
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telephone line connection terminals for connection to telephone lines; an oscillator having an oscillator frequency control input; a DC-to-DC conversion circuit connected to be driven and controlled by said oscillator, said DC-to-DC conversion circuit being connected to draw and process electrical power from said terminals and to provide a supply of processed electrical power to output terminals; and an activation signal detector having an input coupled to said telephone line connection terminals, said activation signal detector detecting the presence of a predetermined activation signal on said telephone lines and an output of said activation signal detector being connected to said oscillator frequency control input for controlling the frequency of the oscillator. - View Dependent Claims (20)
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Specification