Pager operated control unit

• US 5,798,707 A
• Filed: 12/12/1995
• Issued: 08/25/1998
• Est. Priority Date: 03/16/1994
• Status: Expired due to Fees

• Current Assignee: Center For New Product Development
• Original Assignee: Center For New Product Development
• Inventors: Camire, Arthur J.
• Primary Examiner(s): ZIMMERMAN, BRIAN A
• Application Number:
  US08/571,024
• Time in Patent Office: 987 Days
• Field of Search: 340/825.44, 340/825.69, 340/825.72, 340/825.37, 340/635, 340/636, 379/102
• US Class Current: 340/7.1
• CPC Class Codes: G08B 5/228 combined with other devices having a different main function, e.g. watches

Abstract

A pager operated control unit has input terminals of the control circuit are connected to the battery terminals of the pager and power is supplied to the pager receiver from the control circuit. Pager generated pulses are detected by the detection of changes in current drawn by the pager receiver. The control unit includes a pair of capacitors which are alternately charged under the control of a flip-flop in response to bursts of pulses generated by a pager receiver. An output relay is operated to one state when the charges on the two capacitors substantially equal, indicating the receipt of a burst of pulses of equal duration, and operated to another state when the capacitors have unequal charges, indicating the receipt of a burst of pulses of unequal duration.

Claims

1. A pager operated control circuit for use with a pager receiver generating bursts of pulses of a first type and bursts of pulses of a second type and comprising power terminals for connection to a power supply, the control circuit comprising:

an input terminal connectable to a power terminal of the pager receiver;

a detector circuit responsive to current flow in the pager receiver to generate a first detector output signal when pulses of the first type are generated by the pager receiver and to generate a second detector output signal when pulses of the second type are generated by the pager receiver; and

a two state output device responsive to the first and second detector output signals to selectively assume first and second output states;

the detector comprising first and second capacitors and a charge control circuit for alternately charging the first and second capacitors in response to sequentially occurring pulses of a burst of pulses generated by the pager receiver and output circuitry responsive to electrical charge on the capacitors to generate the detector output signals;

the charge control circuit comprising an input circuit connected to the input terminal and responsive to a current flow in the pager receiver of a magnitude greater than a predetermined magnitude, indicative of the generation of pulses by the pager receiver, to generate an input control signal and circuitry responsive to the input control signal to alternately charge the first and second capacitors;

the charge control circuit further comprising a flip-flop circuit having an input terminal connected to the input circuit and first and second output terminals and wherein the charge control circuit further comprises a first gating circuit connected to the input circuit and to the first flip-flop output terminal and a second gating circuit connected to the input circuit and to the second flip-flop output terminal, the first and second gating circuits responsive to the input control signal and the state of the flip-flop to alternately charge the first and second capacitors, respectively.

2. A pager operated control circuit for use with a pager receiver generating bursts of pulses of a first type and bursts of pulses of a second type and comprising power terminals for connection to a power supply, the control circuit comprising:

an input terminal connectable to a power terminal of the pager receiver;

a detector circuit responsive to current flow in the pager receiver to generate a first detector output signal when pulses of the first type are generated by the pager receiver and to generate a second detector output signal when pulses of the second type are generated by the pager receiver, the detector comprising first and second capacitors and a charge control circuit for alternately charging the first and second capacitors in response to sequentially occurring pulses of a burst of pulses generated by the pager receiver and output circuitry responsive to electrical charge on the capacitors to generate the detector output signals, the charge control circuit comprising an input circuit connected to the input terminal and responsive to a current flow in the pager receiver of a magnitude greater than a predetermined magnitude, indicative of the generation of pulses by the pager receiver, to generate an input control signal and circuitry responsive to the input control signal to alternately charge the first and second capacitors, the detector circuit comprising comparator circuitry connected to the capacitors and responsive to signals corresponding to charges on the first and second capacitors to selectively generate the first and second detector output signals, the comparator circuitry comprising circuitry connected to the first and second capacitors and generating a first threshold signal having a magnitude greater than a voltage level corresponding to the charge on one of the capacitors and a second threshold signal having a magnitude less than the voltage level corresponding to the charge on one of the capacitors and output circuitry for generating the first detector output signal when the voltage level corresponding to the charge on the other of the capacitors falls within a range defined between the magnitude of the first threshold signal and the magnitude of the second threshold signal and generating the second detector output signal when the voltage level corresponding to the charge on the other of the capacitors falls outside the range, and a two state output device responsive to the first and second detector output signals to selectively assume first and second output states.

3. The control circuit in accordance with claims 2 wherein the two state output device comprises a bistable latching relay.

4. A pager operated control circuit for use with a pager receiver generating bursts of pulses of a first type and bursts of pulses of a second type and comprising power terminals for connection to a power supply, the control circuit comprising:

an input terminal connectable to a power terminal of the pager receiver;

a detector circuit responsive to current flow in the pager receiver to generate a first detector output signal when pulses of the first type are generated by the pager receiver and to generate a second detector output signal when pulses of the second type are generated by the pager receiver, the detector circuit comprising an integrating circuit for storing an indication of pulses of the first type and pulses of the second type generated by the pager receiver and circuitry responsive to the stored indication of pulses of the first type and pulses of the second type to generate the detector output signals; and

a two state output device responsive to the first and second detector output signals to selectively assume first and second output states.

5. A pager operated control circuit for use with a pager receiver generating bursts of pulses of a first type and bursts of pulses of a second type, the pulses of bursts of pulses of the first type being of equal duration and pulses of bursts of pulses of the second type being of unequal duration, the pager operated control circuit comprising power terminals for connection to a power supply, the control circuit comprising:

an input terminal connectable to a power terminal of the pager receiver;

a detector circuit responsive to current flow in the pager receiver to generate a first detector output signal when pulses of the first type are generated by the pager receiver and to generate a second detector output signal when pulses of the second type are generated by the pager receiver;

the detector circuit comprising first and second capacitors and a charge control circuit for alternately charging the first and second capacitors in response to sequentially occurring pulses of a burst of pulses generated by the pager receiver and output circuitry responsive to electrical charge on the capacitors to generate the detector output signals; and

a two state output device responsive to the first and second detector output signals to selectively assume first and second output states.

6. The control circuit in accordance with claim 5 wherein the charge control circuit comprises an input circuit connected to the input terminal and responsive to a current flow in the pager receiver of a magnitude greater than a predetermined magnitude, indicative of the generation of pulses by the pager receiver, to generate an input control signal and circuitry responsive to the input control signal to alternately charge the first and second capacitors.