Dimming circuit having switching transistor protection means
Patent 4739226 Issued on April 19, 1988. Estimated Expiration Date: 
April 17, 2006. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
April 17, 2006. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3263119 3578983 3889159 D.C. power supply circuit Protection circuit for transistorized switch Dimmer Transistor switching means Protective circuit for a switching transistor Lamp drive circuit Patent #: 4593233 InventorAssigneeApplicationNo. 06/853179 filed on 04/17/1986US Classes:315/224, Impedance or current regulator in the supply circuit307/10.8, Lighting circuits315/127, Supply circuit current and/or potential actuated switch315/209R, PERIODIC SWITCH IN THE SUPPLY CIRCUIT315/225, Periodic switch cut-out315/246, PULSATING OR A.C. SUPPLY315/287, Periodic-type current and/or voltage regulator in the supply circuit315/307, Automatic regulation315/82, Head light systems361/101, With transistor circuit interrupter361/111, Transient responsive361/71, Automatic reclosing361/79, Voltage and current361/98TransistorizedExaminersPrimary: Moore, David K.Assistant: Powell, Mark R. Attorney, Agent or FirmInternational ClassesH03K 17/082 (20060101)H05B 39/04 (20060101) H05B 39/00 (20060101) Foreign Application Priority Data1985-04-18 JPAbstractA dimming circuit adjusts the light output of a lamp by controlling the current flow in the lamp that is connected to a transistor, through turning on and off the transistor with a predetermined timing which is changed by the control signal from a control signal generating circuit. The dimming circuit has a protective circuit for applying an off-state command signal to switch the transistor to the off-state by detecting an excess current flowing in the transistor when an input signal is applied as a control signal for switching the transistor to the on-state. | |
