Patents by Inventor Joan M. Stevenson

Joan M. Stevenson 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).

  • Patent number: 4432624
    Abstract: A relatively inexpensive electronic delay timer particularly suitable for portable use in such applications as control of a camera shutter. The timer can be used in either a leading or trailing mode and employs a small 6V battery as a power source. An integrated circuit timer device is arranged to provide an output signal at the end of a time delay period which can be variably selected by means of a built-in capacitive-resistive network and which is arranged to start in response to a movement of an external control switch. The output signal triggers a second time period of predetermined duration in a second integrated circuit timer during which time a second output signal is generated thereform which is used to activate a transistor device, allowing a capacitor in the circuit to discharge therethrough and through a solenoid which is mechanically coupled to the camera shutter. When the second output signal ceases, at the end of the second time period, the transistor is deactivated and the capacitor recharges.
    Type: Grant
    Filed: February 16, 1982
    Date of Patent: February 21, 1984
    Assignee: Queen's University at Kingston
    Inventors: Joan M. Stevenson, Mark G. Pipkorn