Patents by Inventor Allan Jackson

Allan Jackson has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Power supply circuit for a subscriber's telephone set
    Patent number: 4197425
    Abstract: A power supply circuit for providing a local power supply replenished from the exchange for a telephone instrument. An electrical energy storage device is connected in parallel with an impedance by a device providing a unidirectional transfer of electrical energy from a direct current path through the impedance. A by-pass circuit is connected in parallel with the impedance. The impedance is a zener diode, the storage device is a capacitor, the unidirectional transfer device is a diode, and the by-pass circuit is a transistor responsive to the state of charge of the capacitor. A trickle charge circuit is connected to transfer energy to the capacitor irrespective of the by-pass circuit and a speech-frequency by-pass circuit is in parallel with the zener diode. A switch responsive to on-hook/off-hook conditions is used to confine energy storage to off-hook periods.
    Type: Grant
    Filed: August 10, 1978
    Date of Patent: April 8, 1980
    Assignee: The Post Office
    Inventors: Malcolm R. Secrett, Allan Jackson